diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeInterval.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeInterval.java
index 442cda0..9ccd5ff 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeInterval.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeInterval.java
@@ -13,12 +13,14 @@
 limitations under the License.*/
 package org.onosproject.yangutils.datamodel;
 
+import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
+
 /**
  * Represents single interval information of a range.
  *
- * @param <T> range type based on the data type.
+ * @param <T> range type based on the data type
  */
-public class YangRangeInterval<T extends Comparable<T>> {
+public class YangRangeInterval<T extends YangBuiltInDataTypeInfo<T>> {
 
     /**
      * Starting value of the range interval.
@@ -39,7 +41,7 @@
     /**
      * Returns the starting value of the range interval.
      *
-     * @return the starting value of the range interval.
+     * @return the starting value of the range interval
      */
     public T getStartValue() {
         return startValue;
@@ -48,7 +50,7 @@
     /**
      * Sets the starting value of the range interval.
      *
-     * @param startValue the starting value of the range interval.
+     * @param startValue the starting value of the range interval
      */
     public void setStartValue(T startValue) {
         this.startValue = startValue;
@@ -57,7 +59,7 @@
     /**
      * Returns the last value of the range interval.
      *
-     * @return last value of the range interval.
+     * @return last value of the range interval
      */
     public T getEndValue() {
         return endValue;
@@ -66,7 +68,7 @@
     /**
      * Sets the last value of the range interval.
      *
-     * @param endValue last value of the range interval.
+     * @param endValue last value of the range interval
      */
     public void setEndValue(T endValue) {
         this.endValue = endValue;
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
index 09eb796..38b48bd 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
@@ -20,7 +20,9 @@
 import java.util.List;
 
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
 
+import static org.onosproject.yangutils.utils.builtindatatype.BuiltInTypeObjectFactory.getDataObjectFromString;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 /*-
@@ -47,12 +49,14 @@
  *  "max". "min" and "max" mean the minimum and maximum value accepted
  *  for the type being restricted, respectively.
  */
+
 /**
  * Represents ascending range restriction information.
  *
  * @param <T> range type (data type)
  */
-public class YangRangeRestriction<T extends Comparable<T>> implements YangDesc, YangReference, YangAppErrorInfo {
+public class YangRangeRestriction<T extends YangBuiltInDataTypeInfo<T>>
+        implements YangDesc, YangReference, YangAppErrorInfo {
 
     /**
      * Ascending list of range interval restriction. If the restriction is a
@@ -171,6 +175,37 @@
     }
 
     /**
+     * Check if the given value is correct as per the restriction.
+     *
+     * @param valueInString value
+     * @return true, if the value is confirming to restriction, false otherwise
+     * @throws DataModelException data model error
+     */
+    public boolean isValidValueString(String valueInString) throws DataModelException {
+
+        if (getAscendingRangeIntervals() == null
+                || getAscendingRangeIntervals().size() == 0) {
+            // Throw exception, At least one default range needs to be set in constructor or in linker.
+            throw new DataModelException("Range interval missing in range restriction.");
+
+        }
+
+        YangDataTypes type = getAscendingRangeIntervals().get(0).getStartValue().getYangType();
+        YangBuiltInDataTypeInfo<?> value = getDataObjectFromString(valueInString, type);
+
+        for (YangRangeInterval<T> interval : getAscendingRangeIntervals()) {
+            int rangeStartCompareRes = interval.getStartValue().compareTo((T) value);
+            int rangeEndCompareRes = interval.getEndValue().compareTo((T) value);
+
+            if (rangeStartCompareRes <= 0 && rangeEndCompareRes >= 0) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
      * Returns the textual reference of the length restriction.
      *
      * @return textual reference of the length restriction
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangStringRestriction.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangStringRestriction.java
index 50a1f83..f2c67c3 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangStringRestriction.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangStringRestriction.java
@@ -16,7 +16,7 @@
 
 package org.onosproject.yangutils.datamodel;
 
-import java.math.BigInteger;
+import org.onosproject.yangutils.utils.builtindatatype.YangUint64;
 
 /*-
  * Reference RFC 6020.
@@ -64,10 +64,11 @@
      *  | reference     | 7.19.4  | 0..1        | string          |
      *  +---------------+---------+-------------+-----------------+
      */
+
     /**
      * Length restriction information.
      */
-    private YangRangeRestriction<BigInteger> lengthRestriction;
+    private YangRangeRestriction<YangUint64> lengthRestriction;
 
     /**
      * Effective pattern restriction for the type.
@@ -85,7 +86,7 @@
      *
      * @return length restriction on the string data
      */
-    public YangRangeRestriction<BigInteger> getLengthRestriction() {
+    public YangRangeRestriction<YangUint64> getLengthRestriction() {
         return lengthRestriction;
     }
 
@@ -94,7 +95,7 @@
      *
      * @param lengthRestriction length restriction on the string data
      */
-    public void setLengthRestriction(YangRangeRestriction<BigInteger> lengthRestriction) {
+    public void setLengthRestriction(YangRangeRestriction<YangUint64> lengthRestriction) {
         this.lengthRestriction = lengthRestriction;
     }
 
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
index d315d9b..51f3928 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
@@ -46,6 +46,7 @@
 import org.onosproject.yangutils.parser.impl.listeners.KeyListener;
 import org.onosproject.yangutils.parser.impl.listeners.LeafListListener;
 import org.onosproject.yangutils.parser.impl.listeners.LeafListener;
+import org.onosproject.yangutils.parser.impl.listeners.LengthRestrictionListener;
 import org.onosproject.yangutils.parser.impl.listeners.ListListener;
 import org.onosproject.yangutils.parser.impl.listeners.MandatoryListener;
 import org.onosproject.yangutils.parser.impl.listeners.MaxElementsListener;
@@ -55,6 +56,7 @@
 import org.onosproject.yangutils.parser.impl.listeners.NamespaceListener;
 import org.onosproject.yangutils.parser.impl.listeners.OrganizationListener;
 import org.onosproject.yangutils.parser.impl.listeners.OutputListener;
+import org.onosproject.yangutils.parser.impl.listeners.PatternRestrictionListener;
 import org.onosproject.yangutils.parser.impl.listeners.PositionListener;
 import org.onosproject.yangutils.parser.impl.listeners.PrefixListener;
 import org.onosproject.yangutils.parser.impl.listeners.PresenceListener;
@@ -586,7 +588,7 @@
 
     @Override
     public void enterLengthStatement(GeneratedYangParser.LengthStatementContext ctx) {
-        // TODO: implement the method.
+        LengthRestrictionListener.processLengthRestrictionEntry(this, ctx);
     }
 
     @Override
@@ -596,7 +598,7 @@
 
     @Override
     public void enterPatternStatement(GeneratedYangParser.PatternStatementContext ctx) {
-        // TODO: implement the method.
+        PatternRestrictionListener.processPatternRestrictionEntry(this, ctx);
     }
 
     @Override
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListener.java
new file mode 100644
index 0000000..51a29d5
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListener.java
@@ -0,0 +1,198 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.util.regex.Pattern;
+
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.datamodel.YangRangeInterval;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+import org.onosproject.yangutils.utils.YangConstructType;
+import org.onosproject.yangutils.utils.builtindatatype.DataTypeException;
+import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
+
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
+import static org.onosproject.yangutils.utils.YangConstructType.LENGTH_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.builtindatatype.BuiltInTypeObjectFactory.getDataObjectFromString;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ *  length-stmt         = length-keyword sep length-arg-str optsep
+ *                        (";" /
+ *                         "{" stmtsep
+ *                             ;; these stmts can appear in any order
+ *                             [error-message-stmt stmtsep]
+ *                             [error-app-tag-stmt stmtsep]
+ *                             [description-stmt stmtsep]
+ *                             [reference-stmt stmtsep]
+ *                          "}")
+ *
+ *
+ * ANTLR grammar rule
+ * lengthStatement : LENGTH_KEYWORD length
+ *                 (STMTEND | LEFT_CURLY_BRACE commonStatements RIGHT_CURLY_BRACE);
+ */
+
+/**
+ * Represents listener based call back function corresponding to the "length"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class LengthRestrictionListener {
+
+    private static final String PIPE = "|";
+    private static final String LENGTH_INTERVAL = "..";
+
+    /**
+     * Creates a new length restriction listener.
+     */
+    private LengthRestrictionListener() {
+    }
+
+    /**
+     * It is called when parser receives an input matching the grammar
+     * rule (length), performs validation and updates the data model
+     * tree.
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processLengthRestrictionEntry(TreeWalkListener listener,
+                                                    GeneratedYangParser.LengthStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, LENGTH_DATA, ctx.length().getText(), ENTRY);
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        if (tmpData.getYangConstructType() == TYPE_DATA) {
+            YangType type = (YangType) tmpData;
+            setLengthRestriction(type, ctx);
+        } else {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LENGTH_DATA,
+                    ctx.length().getText(), ENTRY));
+        }
+    }
+
+    /**
+     * Sets the length restriction to type.
+     *
+     * @param type Yang type for which length restriction to be set
+     * @param ctx context object of the grammar rule
+     */
+    private static void setLengthRestriction(YangType type,
+                                            GeneratedYangParser.LengthStatementContext ctx) {
+
+        YangStringRestriction stringRestriction;
+        YangBuiltInDataTypeInfo<?> startValue, endValue;
+        YangRangeRestriction lengthRestriction = new YangRangeRestriction<>();
+
+        if (type.getDataType() != YangDataTypes.STRING && type.getDataType() != YangDataTypes.DERIVED) {
+
+            ParserException parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(LENGTH_DATA) + " name " + ctx.length().getText() +
+                    " can be used to restrict the built-in type string or types derived from string.");
+            parserException.setLine(ctx.getStart().getLine());
+            parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+            throw parserException;
+        }
+
+        if (type.getDataType() == YangDataTypes.STRING) {
+            stringRestriction = (YangStringRestriction) type.getDataTypeExtendedInfo();
+        } else {
+            stringRestriction = (YangStringRestriction) ((YangDerivedInfo<?>) type
+                    .getDataTypeExtendedInfo()).getExtendedInfo();
+        }
+
+        if (stringRestriction == null) {
+            stringRestriction = new YangStringRestriction();
+            if (type.getDataType() == YangDataTypes.STRING) {
+                type.setDataTypeExtendedInfo(stringRestriction);
+            } else {
+                ((YangDerivedInfo<YangStringRestriction>) type.getDataTypeExtendedInfo())
+                        .setExtendedInfo(stringRestriction);
+            }
+        }
+
+        String rangeArgument = removeQuotesAndHandleConcat(ctx.length().getText());
+        String[] rangeArguments = rangeArgument.trim().split(Pattern.quote(PIPE));
+
+        for (String rangePart : rangeArguments) {
+            String startInterval, endInterval;
+            YangRangeInterval rangeInterval = new YangRangeInterval<>();
+            String[] rangeBoundary = rangePart.trim().split(Pattern.quote(LENGTH_INTERVAL));
+
+            if (rangeBoundary.length > 2) {
+                ParserException parserException = new ParserException("YANG file error : " +
+                        YangConstructType.getYangConstructType(LENGTH_DATA) + " " + rangeArgument +
+                        " is not valid.");
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
+            }
+
+            if (rangeBoundary.length == 1) {
+                startInterval = rangeBoundary[0];
+                endInterval = rangeBoundary[0];
+            } else {
+                startInterval = rangeBoundary[0];
+                endInterval = rangeBoundary[1];
+            }
+
+            try {
+                startValue = getDataObjectFromString(startInterval, YangDataTypes.UINT64);
+                endValue = getDataObjectFromString(endInterval, YangDataTypes.UINT64);
+            } catch (DataTypeException e) {
+                ParserException parserException = new ParserException(e.getMessage());
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
+            }
+
+            rangeInterval.setStartValue(startValue);
+            rangeInterval.setEndValue(endValue);
+
+            try {
+                lengthRestriction.addRangeRestrictionInterval(rangeInterval);
+            } catch (DataModelException e) {
+                ParserException parserException = new ParserException(constructExtendedListenerErrorMessage(
+                        UNHANDLED_PARSED_DATA, LENGTH_DATA, rangeArgument, ENTRY, e.getMessage()));
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
+            }
+        }
+
+        stringRestriction.setLengthRestriction(lengthRestriction);
+    }
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListener.java
new file mode 100644
index 0000000..b06ecb5
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListener.java
@@ -0,0 +1,134 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+import org.onosproject.yangutils.utils.YangConstructType;
+
+import static org.onosproject.yangutils.utils.YangConstructType.PATTERN_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ *  pattern-stmt        = pattern-keyword sep string optsep
+ *                        (";" /
+ *                         "{" stmtsep
+ *                             ;; these stmts can appear in any order
+ *                             [error-message-stmt stmtsep]
+ *                             [error-app-tag-stmt stmtsep]
+ *                             [description-stmt stmtsep]
+ *                             [reference-stmt stmtsep]
+ *                          "}")
+ *
+ * ANTLR grammar rule
+ *  patternStatement : PATTERN_KEYWORD string (STMTEND | LEFT_CURLY_BRACE commonStatements RIGHT_CURLY_BRACE);
+ */
+
+/**
+ * Represents listener based call back function corresponding to the "pattern"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class PatternRestrictionListener {
+
+    private static final String EMPTY_STRING = "";
+
+    /**
+     * Creates a new pattern restriction listener.
+     */
+    private PatternRestrictionListener() {
+    }
+
+    /**
+     * It is called when parser receives an input matching the grammar
+     * rule (pattern), performs validation and updates the data model
+     * tree.
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processPatternRestrictionEntry(TreeWalkListener listener,
+                                        GeneratedYangParser.PatternStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, PATTERN_DATA, ctx.string().getText(), ENTRY);
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        if (tmpData.getYangConstructType() == TYPE_DATA) {
+            YangType type = (YangType) tmpData;
+            setPatternRestriction(type, ctx);
+        } else {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PATTERN_DATA,
+                    ctx.string().getText(), ENTRY));
+        }
+    }
+
+    /**
+     * Sets the pattern restriction to type.
+     *
+     * @param type Yang type for which pattern restriction to be set
+     * @param ctx context object of the grammar rule
+     */
+    private static void setPatternRestriction(YangType type,
+                                              GeneratedYangParser.PatternStatementContext ctx) {
+
+        YangStringRestriction stringRestriction;
+
+        if (type.getDataType() != YangDataTypes.STRING && type.getDataType() != YangDataTypes.DERIVED) {
+
+            ParserException parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(PATTERN_DATA) + " name " + ctx.string().getText() +
+                    " can be used to restrict the built-in type string or types derived from string.");
+            parserException.setLine(ctx.getStart().getLine());
+            parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+            throw parserException;
+        }
+
+        if (type.getDataType() == YangDataTypes.STRING) {
+            stringRestriction = (YangStringRestriction) type.getDataTypeExtendedInfo();
+        } else {
+            stringRestriction = (YangStringRestriction) ((YangDerivedInfo<?>) type
+                    .getDataTypeExtendedInfo()).getExtendedInfo();
+        }
+
+        if (stringRestriction == null) {
+            stringRestriction = new YangStringRestriction();
+            if (type.getDataType() == YangDataTypes.STRING) {
+                type.setDataTypeExtendedInfo(stringRestriction);
+            } else {
+                ((YangDerivedInfo<YangStringRestriction>) type.getDataTypeExtendedInfo())
+                        .setExtendedInfo(stringRestriction);
+            }
+        }
+
+        String patternArgument = ctx.string().getText().replace("\"", EMPTY_STRING);
+        stringRestriction.addPattern(patternArgument);
+    }
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
index dfb9458..46bc67a 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
@@ -16,29 +16,33 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
-import java.math.BigInteger;
 import java.util.regex.Pattern;
 
-import org.onosproject.yangutils.datamodel.YangType;
-import org.onosproject.yangutils.datamodel.YangRangeRestriction;
 import org.onosproject.yangutils.datamodel.YangRangeInterval;
-import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+import org.onosproject.yangutils.utils.YangConstructType;
+import org.onosproject.yangutils.utils.builtindatatype.DataTypeException;
+import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
 
-import static org.onosproject.yangutils.utils.YangConstructType.RANGE_DATA;
-import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.RANGE_DATA;
+import static org.onosproject.yangutils.utils.builtindatatype.BuiltInTypeObjectFactory.getDataObjectFromString;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -78,8 +82,8 @@
      * rule (range), performs validation and updates the data model
      * tree.
      *
-     * @param listener listener's object.
-     * @param ctx context object of the grammar rule.
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
      */
     public static void processRangeRestrictionEntry(TreeWalkListener listener,
                                                       GeneratedYangParser.RangeStatementContext ctx) {
@@ -100,68 +104,71 @@
     /**
      * Sets the range restriction to type.
      *
-     * @param type YANG type for which range restriction to be added.
-     * @param ctx context object of the grammar rule.
+     * @param type YANG type for which range restriction to be added
+     * @param ctx context object of the grammar rule
      */
     private static void setRangeRestriction(YangType type,
-                                              GeneratedYangParser.RangeStatementContext ctx) {
-        YangRangeRestriction<?> rangeRestriction = null;
-        YangRangeInterval rangeInterval;
+            GeneratedYangParser.RangeStatementContext ctx) {
+
+        YangBuiltInDataTypeInfo<?> startValue, endValue;
+        YangRangeRestriction rangeRestriction = new YangRangeRestriction();
 
         String rangeArgument = removeQuotesAndHandleConcat(ctx.range().getText());
         String[] rangeArguments = rangeArgument.trim().split(Pattern.quote(PIPE));
 
         for (String rangePart : rangeArguments) {
+            String startInterval, endInterval;
+            YangRangeInterval rangeInterval = new YangRangeInterval();
             String[] rangeBoundary = rangePart.trim().split(Pattern.quote(RANGE_INTERVAL));
 
-            if (rangeBoundary.length == 1) {
-                rangeBoundary[1] = rangeBoundary[0];
+            if (rangeBoundary.length > 2) {
+                ParserException parserException = new ParserException("YANG file error : " +
+                        YangConstructType.getYangConstructType(RANGE_DATA) + " " + rangeArgument +
+                        " is not valid.");
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
             }
 
-            if (type.getDataType() == YangDataTypes.INT8) {
-                rangeRestriction = new YangRangeRestriction<Byte>();
-                rangeInterval = new YangRangeInterval<Byte>();
-                rangeInterval.setStartValue(Byte.parseByte(rangeBoundary[0]));
-                rangeInterval.setEndValue(Byte.parseByte(rangeBoundary[1]));
-            } else if ((type.getDataType() == YangDataTypes.INT16)
-                    || (type.getDataType() == YangDataTypes.UINT8)) {
-                rangeRestriction = new YangRangeRestriction<Short>();
-                rangeInterval = new YangRangeInterval<Short>();
-                rangeInterval.setStartValue(Short.parseShort(rangeBoundary[0]));
-                rangeInterval.setEndValue(Short.parseShort(rangeBoundary[1]));
-            } else if ((type.getDataType() == YangDataTypes.INT32)
-                    || (type.getDataType() == YangDataTypes.UINT16)) {
-                rangeRestriction = new YangRangeRestriction<Integer>();
-                rangeInterval = new YangRangeInterval<Integer>();
-                rangeInterval.setStartValue(Integer.parseInt(rangeBoundary[0]));
-                rangeInterval.setEndValue(Integer.parseInt(rangeBoundary[1]));
-            } else if ((type.getDataType() == YangDataTypes.INT64)
-                    || (type.getDataType() == YangDataTypes.UINT32)) {
-                rangeRestriction = new YangRangeRestriction<Long>();
-                rangeInterval = new YangRangeInterval<Long>();
-                rangeInterval.setStartValue(Long.parseLong(rangeBoundary[0]));
-                rangeInterval.setEndValue(Long.parseLong(rangeBoundary[1]));
-            } else if (type.getDataType() == YangDataTypes.UINT64) {
-                rangeRestriction = new YangRangeRestriction<BigInteger>();
-                rangeInterval = new YangRangeInterval<BigInteger>();
-                rangeInterval.setStartValue(new BigInteger(rangeBoundary[0]));
-                rangeInterval.setEndValue(new BigInteger(rangeBoundary[0]));
+            if (rangeBoundary.length == 1) {
+                startInterval = rangeBoundary[0];
+                endInterval = rangeBoundary[0];
             } else {
-                //TODO: support derived for base built in type of string
-                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, RANGE_DATA,
-                        rangeArgument, ENTRY));
+                startInterval = rangeBoundary[0];
+                endInterval = rangeBoundary[1];
             }
 
             try {
+                startValue = getDataObjectFromString(startInterval, type.getDataType());
+                endValue = getDataObjectFromString(endInterval, type.getDataType());
+            } catch (DataTypeException e) {
+                ParserException parserException = new ParserException(e.getMessage());
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
+            }
+
+            rangeInterval.setStartValue(startValue);
+            rangeInterval.setEndValue(endValue);
+
+            try {
                 rangeRestriction.addRangeRestrictionInterval(rangeInterval);
             } catch (DataModelException e) {
-                throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA, RANGE_DATA,
-                        rangeArgument, ENTRY, e.getMessage()));
+                ParserException parserException = new ParserException(constructExtendedListenerErrorMessage(
+                        UNHANDLED_PARSED_DATA, RANGE_DATA, rangeArgument, ENTRY, e.getMessage()));
+                parserException.setLine(ctx.getStart().getLine());
+                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                throw parserException;
             }
         }
 
         if (rangeRestriction != null) {
-            type.setDataTypeExtendedInfo(rangeRestriction);
+            if (type.getDataType() == YangDataTypes.DERIVED) {
+                ((YangDerivedInfo<YangRangeRestriction>) type.getDataTypeExtendedInfo())
+                        .setExtendedInfo(rangeRestriction);
+            } else {
+                type.setDataTypeExtendedInfo(rangeRestriction);
+            }
         }
 
     }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
index 67f2299..b611d6e 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
@@ -98,36 +98,6 @@
         type.setNodeIdentifier(nodeIdentifier);
         type.setDataType(yangDataTypes);
 
-        // Push the type to the stack.
-        listener.getParsedDataStack().push(type);
-    }
-
-    /**
-     * It is called when parser exits from grammar rule (type), it perform
-     * validations and update the data model tree.
-     *
-     * @param listener Listener's object
-     * @param ctx context object of the grammar rule
-     */
-    public static void processTypeExit(TreeWalkListener listener,
-            GeneratedYangParser.TypeStatementContext ctx) {
-
-        // Check for stack to be non empty.
-        checkStackIsNotEmpty(listener, MISSING_CURRENT_HOLDER, TYPE_DATA, ctx.string().getText(), EXIT);
-
-        Parsable parsableType = listener.getParsedDataStack().pop();
-        if (!(parsableType instanceof YangType)) {
-            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, TYPE_DATA,
-                    ctx.string().getText(), EXIT));
-        }
-
-        YangType<?> type = (YangType<?>) parsableType;
-
-        // Check for stack to be non empty.
-        checkStackIsNotEmpty(listener, MISSING_HOLDER, TYPE_DATA, ctx.string().getText(), EXIT);
-
-        YangDataTypes yangDataTypes = YangDataTypes.getType(ctx.string().getText());
-
         int errorLine = ctx.getStart().getLine();
         int errorPosition = ctx.getStart().getCharPositionInLine();
 
@@ -242,12 +212,35 @@
                 throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, TYPE_DATA,
                         ctx.string().getText(), EXIT));
         }
+
+        // Push the type to the stack.
+        listener.getParsedDataStack().push(type);
     }
 
     /**
-     * Add to resolution list.
+     * It is called when parser exits from grammar rule (type), it perform
+     * validations and update the data model tree.
      *
-     * @param resolutionInfo resolution information.
+     * @param listener Listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processTypeExit(TreeWalkListener listener,
+            GeneratedYangParser.TypeStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_CURRENT_HOLDER, TYPE_DATA, ctx.string().getText(), EXIT);
+
+        Parsable parsableType = listener.getParsedDataStack().pop();
+        if (!(parsableType instanceof YangType)) {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, TYPE_DATA,
+                    ctx.string().getText(), EXIT));
+        }
+    }
+
+    /**
+     * Adds to resolution list.
+     *
+     * @param resolutionInfo resolution information
      * @param ctx context object of the grammar rule
      */
     private static void addToResolutionList(YangResolutionInfo<YangType> resolutionInfo,
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/YangConstructType.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/YangConstructType.java
index f60b650..f9a6fda 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/YangConstructType.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/YangConstructType.java
@@ -277,7 +277,17 @@
     /**
      * Identifies the YANG range element parsed data.
      */
-    RANGE_DATA;
+    RANGE_DATA,
+
+    /**
+     * Identifies the YANG length element parsed data.
+     */
+    LENGTH_DATA,
+
+    /**
+     * Identifies the YANG pattern element parsed data.
+     */
+    PATTERN_DATA;
 
     /**
      * Returns the YANG construct keyword corresponding to enum values.
@@ -392,6 +402,10 @@
                 return "union";
             case RANGE_DATA:
                 return "range";
+            case LENGTH_DATA:
+                return "length";
+            case PATTERN_DATA:
+                return "pattern";
             default:
                 return "yang";
         }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/BuiltInTypeObjectFactory.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/BuiltInTypeObjectFactory.java
new file mode 100644
index 0000000..7002129
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/BuiltInTypeObjectFactory.java
@@ -0,0 +1,75 @@
+/*-
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Factory to create an object of required type.
+ */
+public final class BuiltInTypeObjectFactory {
+
+    /**
+     * Utility factory class, hence the object creation is forbidden.
+     */
+    private BuiltInTypeObjectFactory() {
+    }
+
+    /**
+     * Given the value represented in string return the corresponding types
+     * object with the value initialized.
+     *
+     * @param valueInStr value represented in string
+     * @param builtInType built in data type
+     * @return the target data type object with the value initialized
+     * @param <T> the data type of the target object
+     */
+    public static <T extends YangBuiltInDataTypeInfo<?>> T getDataObjectFromString(String valueInStr,
+            YangDataTypes builtInType) {
+
+        switch (builtInType) {
+            case INT8: {
+                return (T) new YangInt8(valueInStr);
+            }
+            case INT16: {
+                return (T) new YangInt16(valueInStr);
+            }
+            case INT32: {
+                return (T) new YangInt32(valueInStr);
+            }
+            case INT64: {
+                return (T) new YangInt64(valueInStr);
+            }
+            case UINT8: {
+                return (T) new YangUint8(valueInStr);
+            }
+            case UINT16: {
+                return (T) new YangUint16(valueInStr);
+            }
+            case UINT32: {
+                return (T) new YangUint32(valueInStr);
+            }
+            case UINT64: {
+                return (T) new YangUint64(valueInStr);
+            }
+            default: {
+                throw new DataTypeException("YANG file error : Unsupported data type");
+            }
+        }
+
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/DataTypeException.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/DataTypeException.java
new file mode 100644
index 0000000..4cad2cd
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/DataTypeException.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.builtindatatype;
+
+/**
+ * Base class for exceptions in data type.
+ */
+public class DataTypeException extends RuntimeException {
+
+    private static final long serialVersionUID = 20160211L;
+
+    /**
+     * Create a new data type exception.
+     */
+    public DataTypeException() {
+        super();
+    }
+
+    /**
+     * Creates a new data type exception with given message.
+     *
+     * @param message the detail of exception in string
+     */
+    public DataTypeException(String message) {
+        super(message);
+    }
+
+    /**
+     * Creates a new data type exception from given message and cause.
+     *
+     * @param message the detail of exception in string
+     * @param cause underlying cause of the error
+     */
+    public DataTypeException(final String message, final Throwable cause) {
+        super(message, cause);
+    }
+
+    /**
+     * Creates a new data type exception from cause.
+     *
+     * @param cause underlying cause of the error
+     */
+    public DataTypeException(final Throwable cause) {
+        super(cause);
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangBuiltInDataTypeInfo.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangBuiltInDataTypeInfo.java
new file mode 100644
index 0000000..437fe0f
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangBuiltInDataTypeInfo.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Represents the list of utility functions to be supported by YANG built in
+ * data type implementations.
+ *
+ * @param <T> The target data type
+ */
+public interface YangBuiltInDataTypeInfo<T> extends Comparable<T> {
+
+    /**
+     * Returns the YANG built in type.
+     *
+     * @return the YANG built in type
+     */
+    YangDataTypes getYangType();
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt16.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt16.java
new file mode 100644
index 0000000..1ad76b5
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt16.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+
+/**
+ * Handles the YANG's int16 data type processing.
+ *
+ * int16 represents integer values between -32768 and 32767, inclusively.
+ */
+public class YangInt16 implements YangBuiltInDataTypeInfo<YangInt16> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's int16.
+     */
+    public static final short MIN_VALUE = -32768;
+
+    /**
+     * Valid maximum value of YANG's int16.
+     */
+    public static final short MAX_VALUE = 32767;
+
+    /**
+     * The value of YANG's int16.
+     */
+    private final short value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    public YangInt16(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Short.parseShort(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+    }
+
+    /**
+     * Returns YANG's int16 value.
+     *
+     * @return value of YANG's int16
+     */
+    public short getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangInt16 anotherYangInt16) {
+        return Short.compare(value, anotherYangInt16.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.INT16;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt32.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt32.java
new file mode 100644
index 0000000..93dcec6
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt32.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's int32 data type processing.
+ *
+ * int32 represents integer values between -2147483648 and 2147483647, inclusively.
+ */
+public class YangInt32 implements YangBuiltInDataTypeInfo<YangInt32> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's int32.
+     */
+    public static final int MIN_VALUE = -2147483648;
+
+    /**
+     * Valid maximum value of YANG's int32.
+     */
+    public static final int MAX_VALUE = 2147483647;
+
+    /**
+     * The value of YANG's int32.
+     */
+    private final int value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    public YangInt32(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Integer.parseInt(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+    }
+
+
+    /**
+     * Returns YANG's int32 value.
+     *
+     * @return value of YANG's int32
+     */
+    public int getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangInt32 anotherYangInt32) {
+        return Integer.compare(value, anotherYangInt32.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.INT32;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt64.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt64.java
new file mode 100644
index 0000000..a046ee8
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt64.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's int8 data type processing.
+ *
+ * int8 represents integer values between -9223372036854775808 and 9223372036854775807, inclusively.
+ */
+public class YangInt64 implements YangBuiltInDataTypeInfo<YangInt64> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's int64.
+     */
+    public static final Long MIN_VALUE = 0x8000000000000000L;
+
+    /**
+     * Valid maximum value of YANG's int64.
+     */
+    public static final long MAX_VALUE = 0x7fffffffffffffffL;
+
+    /**
+     * The value of YANG's int64.
+     */
+    private final long value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    public YangInt64(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Long.parseLong(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+    }
+
+
+    /**
+     * Returns YANG's int64 value.
+     *
+     * @return value of YANG's int64
+     */
+    public long getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangInt64 anotherYangInt64) {
+        return Long.compare(value, anotherYangInt64.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.INT64;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt8.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt8.java
new file mode 100644
index 0000000..c902410
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangInt8.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's int8 data type processing.
+ *
+ * int8 represents integer values between -128 and 127, inclusively.
+ */
+public class YangInt8 implements YangBuiltInDataTypeInfo<YangInt8> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's int8.
+     */
+    public static final byte MIN_VALUE = -128;
+
+    /**
+     * Valid maximum value of YANG's int8.
+     */
+    public static final byte MAX_VALUE = 127;
+
+    /**
+     * The value of YANG's int8.
+     */
+    private final byte value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    public YangInt8(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Byte.parseByte(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+    }
+
+    /**
+     * Returns YANG's int8 value.
+     *
+     * @return value of YANG's int8
+     */
+    public byte getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangInt8 anotherYangInt8) {
+        return Byte.compare(value, anotherYangInt8.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.INT8;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint16.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint16.java
new file mode 100644
index 0000000..b109103
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint16.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's Uint16 data type processing.
+ *
+ * Uint16 represents integer values between 0 and 65535, inclusively.
+ */
+public class YangUint16 implements YangBuiltInDataTypeInfo<YangUint16> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's Uint16.
+     */
+    public static final int MIN_VALUE = 0;
+
+    /**
+     * Valid maximum value of YANG's Uint16.
+     */
+    public static final int MAX_VALUE = 65535;
+
+    /**
+     * Value of the object.
+     */
+    private int value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    YangUint16(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Integer.parseInt(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+
+        if (value < MIN_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is lesser than minimum value "
+                    + MIN_VALUE + ".");
+        } else if (value > MAX_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is greater than maximum value "
+                    + MAX_VALUE + ".");
+        }
+    }
+
+    /**
+     * Returns YANG's uint16 value.
+     *
+     * @return value of YANG's uint16
+     */
+    public int getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangUint16 another) {
+        return Integer.compare(value, another.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.UINT16;
+    }
+
+}
+
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint32.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint32.java
new file mode 100644
index 0000000..e356055
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint32.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's Uint32 data type processing.
+ *
+ * Uint32 represents integer values between 0 and 4294967295, inclusively.
+ */
+public class YangUint32 implements YangBuiltInDataTypeInfo<YangUint32> {
+
+    private static final String MIN_KEYWORD = "min";
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's Uint32.
+     */
+    public static final long MIN_VALUE = 0;
+
+    /**
+     * Valid maximum value of YANG's Uint32.
+     */
+    public static final long MAX_VALUE = 4294967295L;
+
+    /**
+     * Value of the object.
+     */
+    private long value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    YangUint32(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Long.parseLong(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+
+        if (value < MIN_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is lesser than minimum value "
+                    + MIN_VALUE + ".");
+        } else if (value > MAX_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is greater than maximum value "
+                    + MAX_VALUE + ".");
+        }
+    }
+
+    /**
+     * Returns YANG's uint32 value.
+     *
+     * @return value of YANG's uint32
+     */
+    public long getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangUint32 another) {
+        return Long.compare(value, another.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.UINT32;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint64.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint64.java
new file mode 100644
index 0000000..70001ae
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint64.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import java.math.BigInteger;
+import java.util.regex.Pattern;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's Uint16 data type processing.
+ *
+ * Uint64 represents integer values between 0 and 18446744073709551615, inclusively.
+ */
+public class YangUint64 implements YangBuiltInDataTypeInfo<YangUint64> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * YANG's Integer value pattern.
+     */
+    private static final Pattern NON_NEGATIVE_INTEGER_PATTERN = Pattern.compile("[0-9]+");
+
+    /**
+     * Valid minimum value of YANG's Uint64.
+     */
+    public static final BigInteger MIN_VALUE = BigInteger.valueOf(0);
+
+    /**
+     * Valid maximum value of YANG's Uint64.
+     */
+    public static final BigInteger MAX_VALUE = new BigInteger("18446744073709551615");
+
+    /**
+     * Value of the object.
+     */
+    private BigInteger value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    YangUint64(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else if (NON_NEGATIVE_INTEGER_PATTERN.matcher(valueInString).matches()) {
+            value = new BigInteger(valueInString);
+        } else {
+            throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+        }
+
+        if (value.compareTo(MIN_VALUE) < 0) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is lesser than minimum value "
+                    + MIN_VALUE + ".");
+        } else if (value.compareTo(MAX_VALUE) > 0) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is greater than maximum value "
+                    + MAX_VALUE + ".");
+        }
+    }
+
+    /**
+     * Returns YANG's uint64 value.
+     *
+     * @return value of YANG's uint64
+     */
+    public BigInteger getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangUint64 another) {
+        return value.compareTo(another.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.UINT64;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint8.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint8.java
new file mode 100644
index 0000000..caf0628
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/YangUint8.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
+
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+
+/**
+ * Handles the YANG's Uint8 data type processing.
+ *
+ * Uint8 represents integer values between 0 and 255, inclusively.
+ */
+public class YangUint8 implements YangBuiltInDataTypeInfo<YangUint8> {
+
+    /**
+     * YANG's min keyword.
+     */
+    private static final String MIN_KEYWORD = "min";
+
+    /**
+     * YANG's max keyword.
+     */
+    private static final String MAX_KEYWORD = "max";
+
+    /**
+     * Valid minimum value of YANG's Uint8.
+     */
+    public static final short MIN_VALUE = 0;
+
+    /**
+     * Valid maximum value of YANG's Uint8.
+     */
+    public static final short MAX_VALUE = 255;
+
+    /**
+     * Value of the object.
+     */
+    private short value;
+
+    /**
+     * Creates an object with the value initialized with value represented in
+     * string.
+     *
+     * @param valueInString value of the object in string
+     */
+    YangUint8(String valueInString) {
+
+        if (valueInString.matches(MIN_KEYWORD)) {
+            value = MIN_VALUE;
+        } else if (valueInString.matches(MAX_KEYWORD)) {
+            value = MAX_VALUE;
+        } else {
+            try {
+                value = Short.parseShort(valueInString);
+            } catch (Exception e) {
+                throw new DataTypeException("YANG file error : " + valueInString + " is not valid.");
+            }
+        }
+
+        if (value < MIN_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is lesser than minimum value "
+                    + MIN_VALUE + ".");
+        } else if (value > MAX_VALUE) {
+            throw new DataTypeException("YANG file error : " + valueInString + " is greater than maximum value "
+                    + MAX_VALUE + ".");
+        }
+    }
+
+    /**
+     * Returns YANG's uint8 value.
+     *
+     * @return value of YANG's uint8
+     */
+    public short getValue() {
+        return value;
+    }
+
+    @Override
+    public int compareTo(YangUint8 another) {
+        return Short.compare(value, another.value);
+    }
+
+    @Override
+    public YangDataTypes getYangType() {
+        return YangDataTypes.UINT8;
+    }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/package-info.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/package-info.java
new file mode 100644
index 0000000..9d3aa33
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/builtindatatype/package-info.java
@@ -0,0 +1,20 @@
+/*-
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Utilities for YANG built in data types.
+ */
+package org.onosproject.yangutils.utils.builtindatatype;
diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java
new file mode 100644
index 0000000..e5e647a
--- /dev/null
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java
@@ -0,0 +1,237 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangRangeInterval;
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.utils.builtindatatype.YangUint64;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for length restriction listener.
+ */
+public class LengthRestrictionListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid length statement as sub-statement of leaf statement.
+     */
+    @Test
+    public void processValidLengthStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidLengthStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                                                    .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                                                    .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks valid length statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLengthStatementInsideLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthStatementInsideLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks valid length statement as sub-statement of typedef.
+     */
+    @Test
+    public void processLengthStatementInsideTypeDef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthStatementInsideTypeDef.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
+        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getDataType()
+                .getDataTypeExtendedInfo();
+
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks length statement with invalid type.
+     */
+    @Test
+    public void processLengthWithInvalidType() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : length name \"1..100\" can be used to restrict the built-in type" +
+                " string or types derived from string.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidType.yang");
+    }
+
+    /**
+     * Checks length statement with only start interval.
+     */
+    @Test
+    public void processLengthWithOneInterval() throws IOException, ParserException {
+
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithOneInterval.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(1)));
+    }
+
+    /**
+     * Checks length statement with min and max.
+     */
+    @Test
+    public void processLengthWithMinMax() throws IOException, ParserException {
+
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithMinMax.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(new BigInteger("18446744073709551615")));
+    }
+
+    /**
+     * Checks length statement with invalid integer pattern.
+     */
+    @Test
+    public void processLengthWithInvalidIntegerPattern() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : a is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidIntegerPattern.yang");
+    }
+
+    /**
+     * Checks length statement with invalid interval.
+     */
+    @Test
+    public void processLengthWithInvalidInterval() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : 18446744073709551617 is greater than maximum value" +
+                " 18446744073709551615.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidInterval.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
new file mode 100644
index 0000000..ffd8470
--- /dev/null
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
@@ -0,0 +1,169 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangPatternRestriction;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for pattern restriction listener.
+ */
+public class PatternRestrictionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid pattern statement as sub-statement of leaf statement.
+     */
+    @Test
+    public void processValidPatternStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidPatternStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processPatternStatementInsideLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementInsideLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement as sub-statement of typedef.
+     */
+    @Test
+    public void processPatternStatementInsideTypeDef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementInsideTypeDef.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
+        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getDataType()
+                .getDataTypeExtendedInfo();
+
+        YangPatternRestriction yangPatternRestriction = stringRestriction.getPatternRestriction();
+        assertThat(yangPatternRestriction.getPatternList().listIterator().next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid multiple pattern statements.
+     */
+    @Test
+    public void processMultiplePatternStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement with plus symbol in pattern.
+     */
+    @Test
+    public void processPatternStatementWithPlus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementWithPlus.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("-[0-9]+|[0-9]+"));
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java
index 2b7e3a8..3ae527b 100644
--- a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java
@@ -16,11 +16,12 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
-
 import java.io.IOException;
 import java.util.ListIterator;
 
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangLeaf;
 import org.onosproject.yangutils.datamodel.YangLeafList;
@@ -31,6 +32,7 @@
 import org.onosproject.yangutils.datamodel.YangDataTypes;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.utils.builtindatatype.YangInt32;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
@@ -40,6 +42,9 @@
  */
 public class RangeRestrictionListenerTest {
 
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
     private final YangUtilsParserManager manager = new YangUtilsParserManager();
 
     /**
@@ -67,8 +72,8 @@
         ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
                                                     .listIterator();
         YangRangeInterval rangeInterval = rangeListIterator.next();
-        assertThat(rangeInterval.getStartValue(), is(10));
-        assertThat(rangeInterval.getEndValue(), is(20));
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
     }
 
     /**
@@ -97,7 +102,77 @@
                 .listIterator();
         YangRangeInterval rangeInterval = rangeListIterator.next();
 
-        assertThat(rangeInterval.getStartValue(), is(10));
-        assertThat(rangeInterval.getEndValue(), is(20));
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
+
+    /**
+     * Checks valid range statement with one interval.
+     */
+    @Test
+    public void processRangeWithOneInterval() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithOneInterval.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(1));
+    }
+
+    /**
+     * Checks valid range statement with min and max.
+     */
+    @Test
+    public void processRangeWithMinMax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithMinMax.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(-2147483648));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(2147483647));
+    }
+
+    /**
+     * Checks valid range statement with invalid integer pattern.
+     */
+    @Test
+    public void processRangeWithInvalidIntegerPattern() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : a is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithInvalidIntegerPattern.yang");
     }
 }
\ No newline at end of file
diff --git a/utils/yangutils/src/test/resources/LengthStatementInsideLeafList.yang b/utils/yangutils/src/test/resources/LengthStatementInsideLeafList.yang
new file mode 100644
index 0000000..06d08db
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthStatementInsideLeafList.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            length "1..100";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthStatementInsideTypeDef.yang b/utils/yangutils/src/test/resources/LengthStatementInsideTypeDef.yang
new file mode 100644
index 0000000..c1195dc
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthStatementInsideTypeDef.yang
@@ -0,0 +1,15 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    typedef invalid-interval {
+        type string {
+            length "1..100";
+         }
+    }
+    leaf xyz {
+       type invalid-interval {
+           length "2..100";
+       }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthWithInvalidIntegerPattern.yang b/utils/yangutils/src/test/resources/LengthWithInvalidIntegerPattern.yang
new file mode 100644
index 0000000..f5c8a69
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthWithInvalidIntegerPattern.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            length "a..z";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthWithInvalidInterval.yang b/utils/yangutils/src/test/resources/LengthWithInvalidInterval.yang
new file mode 100644
index 0000000..7b4ae18
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthWithInvalidInterval.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            length "0..18446744073709551617";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthWithInvalidType.yang b/utils/yangutils/src/test/resources/LengthWithInvalidType.yang
new file mode 100644
index 0000000..74b183c
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthWithInvalidType.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type int8 {
+            length "1..100";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthWithMinMax.yang b/utils/yangutils/src/test/resources/LengthWithMinMax.yang
new file mode 100644
index 0000000..5884266
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthWithMinMax.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            length "min..max";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/LengthWithOneInterval.yang b/utils/yangutils/src/test/resources/LengthWithOneInterval.yang
new file mode 100644
index 0000000..b160f02
--- /dev/null
+++ b/utils/yangutils/src/test/resources/LengthWithOneInterval.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            length "1";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/MultiplePatternStatement.yang b/utils/yangutils/src/test/resources/MultiplePatternStatement.yang
new file mode 100644
index 0000000..7a47bfc
--- /dev/null
+++ b/utils/yangutils/src/test/resources/MultiplePatternStatement.yang
@@ -0,0 +1,11 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            pattern "[a-zA-Z]";
+            pattern "[a-z]";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/PatternStatementInsideLeafList.yang b/utils/yangutils/src/test/resources/PatternStatementInsideLeafList.yang
new file mode 100644
index 0000000..d21c0f6
--- /dev/null
+++ b/utils/yangutils/src/test/resources/PatternStatementInsideLeafList.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            pattern "[a-zA-Z]";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/PatternStatementInsideTypeDef.yang b/utils/yangutils/src/test/resources/PatternStatementInsideTypeDef.yang
new file mode 100644
index 0000000..edb625e
--- /dev/null
+++ b/utils/yangutils/src/test/resources/PatternStatementInsideTypeDef.yang
@@ -0,0 +1,15 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    typedef invalid-interval {
+        type string {
+            pattern "[a-zA-Z]";
+         }
+    }
+    leaf xyz {
+       type invalid-interval {
+           pattern "[a-z]";
+       }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/PatternStatementWithPlus.yang b/utils/yangutils/src/test/resources/PatternStatementWithPlus.yang
new file mode 100644
index 0000000..417e1d1
--- /dev/null
+++ b/utils/yangutils/src/test/resources/PatternStatementWithPlus.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type string {
+            pattern "-[0-9]+|[0-9]+";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/RangeWithInvalidIntegerPattern.yang b/utils/yangutils/src/test/resources/RangeWithInvalidIntegerPattern.yang
new file mode 100644
index 0000000..60c7992
--- /dev/null
+++ b/utils/yangutils/src/test/resources/RangeWithInvalidIntegerPattern.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type int32 {
+            range "a..z";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/RangeWithMinMax.yang b/utils/yangutils/src/test/resources/RangeWithMinMax.yang
new file mode 100644
index 0000000..373d45e
--- /dev/null
+++ b/utils/yangutils/src/test/resources/RangeWithMinMax.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type int32 {
+            range "min..max";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/RangeWithOneInterval.yang b/utils/yangutils/src/test/resources/RangeWithOneInterval.yang
new file mode 100644
index 0000000..85d0288
--- /dev/null
+++ b/utils/yangutils/src/test/resources/RangeWithOneInterval.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type int32 {
+            range "1";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/ValidLengthStatement.yang b/utils/yangutils/src/test/resources/ValidLengthStatement.yang
new file mode 100644
index 0000000..57cb809
--- /dev/null
+++ b/utils/yangutils/src/test/resources/ValidLengthStatement.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            length "0..100";
+         }
+    }
+}
diff --git a/utils/yangutils/src/test/resources/ValidPatternStatement.yang b/utils/yangutils/src/test/resources/ValidPatternStatement.yang
new file mode 100644
index 0000000..556db31
--- /dev/null
+++ b/utils/yangutils/src/test/resources/ValidPatternStatement.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            pattern "[a-zA-Z]";
+         }
+    }
+}