Defect Fixes and optimization for YANG translator.

Change-Id: I974a968f3c41e1abea9f2567aceb3d523645d0ae
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/plugin/manager/YangUtilManager.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/plugin/manager/YangUtilManager.java
index 3373c65..27e5aa0 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/plugin/manager/YangUtilManager.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/plugin/manager/YangUtilManager.java
@@ -36,12 +36,12 @@
 import static org.apache.maven.plugins.annotations.LifecyclePhase.GENERATE_SOURCES;
 import static org.apache.maven.plugins.annotations.ResolutionScope.COMPILE;
 import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getPackageDirPathFromJavaJPackage;
 import static org.onosproject.yangutils.utils.UtilConstants.DEFAULT_BASE_PKG;
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
 import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.addToSource;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.clean;
-import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.convertPkgToPath;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.copyYangFilesToTarget;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.getDirectory;
 
@@ -89,7 +89,7 @@
     @Component
     private BuildContext context;
 
-    private static final String DEFAULT_PKG = SLASH + convertPkgToPath(DEFAULT_BASE_PKG);
+    private static final String DEFAULT_PKG = SLASH + getPackageDirPathFromJavaJPackage(DEFAULT_BASE_PKG);
 
     private YangUtilsParser yangUtilsParser = new YangUtilsParserManager();
     private String searchDir;
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedMethodTypes.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedMethodTypes.java
deleted file mode 100644
index f733419..0000000
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedMethodTypes.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * 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.translator.tojava;
-
-/**
- * Type of method generated.
- */
-public enum GeneratedMethodTypes {
-    /**
-     * getter method.
-     */
-    GETTER,
-
-    /**
-     * setter method.
-     */
-    SETTER,
-
-    /**
-     * Constructor.
-     */
-    CONSTRUCTOR,
-
-    /**
-     * Build.
-     */
-    BUILD,
-
-    /**
-     * Default Constructor.
-     */
-    DEFAULT_CONSTRUCTOR
-}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/TempJavaCodeFragmentFiles.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/TempJavaCodeFragmentFiles.java
index 2a32819..4ceb55a 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/TempJavaCodeFragmentFiles.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/TempJavaCodeFragmentFiles.java
@@ -284,6 +284,11 @@
     private YangNode curYangNode;
 
     /**
+     * Is attribute added.
+     */
+    private boolean isAttributePresent = false;
+
+    /**
      * Construct an object of temporary java code fragment.
      *
      * @param genFileType file generation type
@@ -684,6 +689,9 @@
      */
     public void setNewAttrInfo(JavaAttributeInfo newAttrInfo) {
 
+        if (newAttrInfo != null) {
+            isAttributePresent = true;
+        }
         this.newAttrInfo = newAttrInfo;
     }
 
@@ -903,9 +911,6 @@
         File file = new File(path + fileName + TEMP_FILE_EXTENSION);
         if (!file.exists()) {
             file.createNewFile();
-        } else {
-            file.delete();
-            file.createNewFile();
         }
         return file;
     }
@@ -965,7 +970,7 @@
          * TODO: check if this utility needs to be called or move to the caller
          */
         String attributeName = JavaIdentifierSyntax
-                .getCamelCase(JavaIdentifierSyntax.getLowerCase(attr.getAttributeName()));
+                .getCamelCase(JavaIdentifierSyntax.getSmallCase(attr.getAttributeName()));
         if (attr.isQualifiedName()) {
             return getJavaAttributeDefination(attr.getImportInfo().getPkgInfo(), attr.getImportInfo().getClassInfo(),
                     attributeName, attr.isListAttr());
@@ -1113,40 +1118,42 @@
             throws IOException {
 
         setNewAttrInfo(newAttrInfo);
-        if ((generatedTempFiles & ATTRIBUTES_MASK) != 0) {
-            addAttribute(newAttrInfo);
-        }
+        if (isAttributePresent) {
+            if ((generatedTempFiles & ATTRIBUTES_MASK) != 0) {
+                addAttribute(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & GETTER_FOR_INTERFACE_MASK) != 0) {
-            addGetterForInterface(newAttrInfo);
-        }
+            if ((generatedTempFiles & GETTER_FOR_INTERFACE_MASK) != 0) {
+                addGetterForInterface(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & SETTER_FOR_INTERFACE_MASK) != 0) {
-            addSetterForInterface(newAttrInfo);
-        }
+            if ((generatedTempFiles & SETTER_FOR_INTERFACE_MASK) != 0) {
+                addSetterForInterface(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & GETTER_FOR_CLASS_MASK) != 0) {
-            addGetterImpl(newAttrInfo, generatedJavaFiles);
-        }
+            if ((generatedTempFiles & GETTER_FOR_CLASS_MASK) != 0) {
+                addGetterImpl(newAttrInfo, generatedJavaFiles);
+            }
 
-        if ((generatedTempFiles & SETTER_FOR_CLASS_MASK) != 0) {
-            addSetterImpl(newAttrInfo);
-        }
+            if ((generatedTempFiles & SETTER_FOR_CLASS_MASK) != 0) {
+                addSetterImpl(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & CONSTRUCTOR_IMPL_MASK) != 0) {
-            addConstructor(newAttrInfo);
-        }
+            if ((generatedTempFiles & CONSTRUCTOR_IMPL_MASK) != 0) {
+                addConstructor(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & HASH_CODE_IMPL_MASK) != 0) {
-            addHashCodeMethod(newAttrInfo);
-        }
+            if ((generatedTempFiles & HASH_CODE_IMPL_MASK) != 0) {
+                addHashCodeMethod(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & EQUALS_IMPL_MASK) != 0) {
-            addEqualsMethod(newAttrInfo);
-        }
+            if ((generatedTempFiles & EQUALS_IMPL_MASK) != 0) {
+                addEqualsMethod(newAttrInfo);
+            }
 
-        if ((generatedTempFiles & TO_STRING_IMPL_MASK) != 0) {
-            addToStringMethod(newAttrInfo);
+            if ((generatedTempFiles & TO_STRING_IMPL_MASK) != 0) {
+                addToStringMethod(newAttrInfo);
+            }
         }
         return;
     }
@@ -1193,7 +1200,7 @@
 
         setCurYangNode(curNode);
         List<String> imports = new ArrayList<>();
-        if (curNode instanceof HasJavaImportData) {
+        if (curNode instanceof HasJavaImportData && isAttributePresent) {
             imports = ((HasJavaImportData) curNode).getJavaImportData().getImports(getNewAttrInfo());
         }
         /**
@@ -1206,13 +1213,14 @@
              * Create interface file.
              */
             setInterfaceJavaFileHandle(getJavaFileHandle(getJavaClassName(INTERFACE_FILE_NAME_SUFFIX)));
-            setInterfaceJavaFileHandle(generateInterfaceFile(getInterfaceJavaFileHandle(), imports, curNode));
+            setInterfaceJavaFileHandle(
+                    generateInterfaceFile(getInterfaceJavaFileHandle(), imports, curNode, isAttributePresent));
             /**
              * Create builder interface file.
              */
             setBuilderInterfaceJavaFileHandle(getJavaFileHandle(getJavaClassName(BUILDER_INTERFACE_FILE_NAME_SUFFIX)));
             setBuilderInterfaceJavaFileHandle(
-                    generateBuilderInterfaceFile(getBuilderInterfaceJavaFileHandle(), curNode));
+                    generateBuilderInterfaceFile(getBuilderInterfaceJavaFileHandle(), curNode, isAttributePresent));
             /**
              * Append builder interface file to interface file and close it.
              */
@@ -1221,7 +1229,7 @@
 
         }
 
-        if (curNode instanceof HasJavaImportData) {
+        if (curNode instanceof HasJavaImportData && isAttributePresent) {
             imports.add(((HasJavaImportData) curNode).getJavaImportData().getImportForHashAndEquals());
             imports.add(((HasJavaImportData) curNode).getJavaImportData().getImportForToString());
             java.util.Collections.sort(imports);
@@ -1234,12 +1242,14 @@
              * Create builder class file.
              */
             setBuilderClassJavaFileHandle(getJavaFileHandle(getJavaClassName(BUILDER_CLASS_FILE_NAME_SUFFIX)));
-            setBuilderClassJavaFileHandle(generateBuilderClassFile(getBuilderClassJavaFileHandle(), imports, curNode));
+            setBuilderClassJavaFileHandle(
+                    generateBuilderClassFile(getBuilderClassJavaFileHandle(), imports, curNode, isAttributePresent));
             /**
              * Create impl class file.
              */
             setImplClassJavaFileHandle(getJavaFileHandle(getJavaClassName(IMPL_CLASS_FILE_NAME_SUFFIX)));
-            setImplClassJavaFileHandle(generateImplClassFile(getImplClassJavaFileHandle(), curNode));
+            setImplClassJavaFileHandle(
+                    generateImplClassFile(getImplClassJavaFileHandle(), curNode, isAttributePresent));
             /**
              * Append impl class to builder class and close it.
              */
@@ -1269,46 +1279,38 @@
      */
     private void close() throws IOException {
 
-        closeFile(getJavaClassName(INTERFACE_FILE_NAME_SUFFIX));
+        if ((generatedJavaFiles & INTERFACE_MASK) != 0) {
+            closeFile(getInterfaceJavaFileHandle(), false);
+        }
 
-        closeFile(getJavaClassName(BUILDER_INTERFACE_FILE_NAME_SUFFIX));
-        getJavaFileHandle(getJavaClassName(BUILDER_INTERFACE_FILE_NAME_SUFFIX)).delete();
+        if ((generatedJavaFiles & BUILDER_CLASS_MASK) != 0) {
+            closeFile(getBuilderClassJavaFileHandle(), false);
+        }
 
-        closeFile(getJavaClassName(BUILDER_CLASS_FILE_NAME_SUFFIX));
+        if ((generatedJavaFiles & BUILDER_INTERFACE_MASK) != 0) {
+            closeFile(getBuilderInterfaceJavaFileHandle(), true);
+        }
 
-        closeFile(getJavaClassName(IMPL_CLASS_FILE_NAME_SUFFIX));
-        getJavaFileHandle(getJavaClassName(IMPL_CLASS_FILE_NAME_SUFFIX)).delete();
+        if ((generatedJavaFiles & IMPL_CLASS_MASK) != 0) {
+            closeFile(getImplClassJavaFileHandle(), true);
+        }
 
-        closeFile(getJavaClassName(TYPEDEF_CLASS_FILE_NAME_SUFFIX));
+        if ((generatedJavaFiles & GENERATE_TYPEDEF_CLASS) != 0) {
+            closeFile(getTypedefClassJavaFileHandle(), false);
+        }
 
-        closeFile(GETTER_METHOD_FILE_NAME);
-        getTemporaryFileHandle(GETTER_METHOD_FILE_NAME).delete();
-
-        closeFile(GETTER_METHOD_IMPL_FILE_NAME);
-        getTemporaryFileHandle(GETTER_METHOD_IMPL_FILE_NAME).delete();
-
-        closeFile(SETTER_METHOD_FILE_NAME);
-        getTemporaryFileHandle(SETTER_METHOD_FILE_NAME).delete();
-
-        closeFile(SETTER_METHOD_IMPL_FILE_NAME);
-        getTemporaryFileHandle(SETTER_METHOD_IMPL_FILE_NAME).delete();
-
-        closeFile(CONSTRUCTOR_FILE_NAME);
-        getTemporaryFileHandle(CONSTRUCTOR_FILE_NAME).delete();
-
-        closeFile(ATTRIBUTE_FILE_NAME);
-        getTemporaryFileHandle(ATTRIBUTE_FILE_NAME).delete();
-
-        closeFile(HASH_CODE_METHOD_FILE_NAME);
-        getTemporaryFileHandle(HASH_CODE_METHOD_FILE_NAME).delete();
-
-        closeFile(TO_STRING_METHOD_FILE_NAME);
-        getTemporaryFileHandle(TO_STRING_METHOD_FILE_NAME).delete();
-
-        closeFile(EQUALS_METHOD_FILE_NAME);
-        getTemporaryFileHandle(EQUALS_METHOD_FILE_NAME).delete();
-
-        clean(getTempDirPath());
+        /**
+         * Close all temporary file handles and delete the files.
+         */
+        closeFile(getGetterInterfaceTempFileHandle(), true);
+        closeFile(getGetterImplTempFileHandle(), true);
+        closeFile(getSetterInterfaceTempFileHandle(), true);
+        closeFile(getSetterImplTempFileHandle(), true);
+        closeFile(getConstructorImplTempFileHandle(), true);
+        closeFile(getAttributesTempFileHandle(), true);
+        closeFile(getHashCodeImplTempFileHandle(), true);
+        closeFile(getToStringImplTempFileHandle(), true);
+        closeFile(getEqualsImplTempFileHandle(), true);
     }
 
     /**
@@ -1317,8 +1319,14 @@
      * @param fileName temporary file's name
      * @throws IOException when failed to close the file handle
      */
-    private void closeFile(String fileName) throws IOException {
+    private void closeFile(File file, boolean toBeDeleted) throws IOException {
 
-        FileSystemUtil.updateFileHandle(new File(fileName), null, true);
+        if (file.exists()) {
+            FileSystemUtil.updateFileHandle(file, null, true);
+            if (toBeDeleted) {
+                file.delete();
+            }
+            clean(getTempDirPath());
+        }
     }
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaContainer.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaContainer.java
index 228b1d8..3c2b773 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaContainer.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaContainer.java
@@ -178,7 +178,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_INTERFACE_WITH_BUILDER, this);
     }
 
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaInput.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaInput.java
index cff69be..f3f3674 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaInput.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaInput.java
@@ -180,7 +180,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_INTERFACE_WITH_BUILDER, this);
     }
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaList.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaList.java
index d911c9a..c504b8f 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaList.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaList.java
@@ -181,7 +181,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_INTERFACE_WITH_BUILDER, this);
     }
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaModule.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaModule.java
index f5775b3..9413c64 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaModule.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaModule.java
@@ -37,8 +37,8 @@
  * Module information extended to support java code generation.
  */
 public class YangJavaModule extends YangModule
-implements JavaCodeGenerator, HasJavaFileInfo,
-HasJavaImportData, HasTempJavaCodeFragmentFiles {
+        implements JavaCodeGenerator, HasJavaFileInfo,
+        HasJavaImportData, HasTempJavaCodeFragmentFiles {
 
     /**
      * Contains the information of the java file being generated.
@@ -76,7 +76,7 @@
     public JavaFileInfo getJavaFileInfo() {
 
         if (javaFileInfo == null) {
-            throw new RuntimeException("Missing java info in java datamodel node.");
+            throw new RuntimeException("Missing java info in java datamodel node");
         }
         return javaFileInfo;
     }
@@ -171,7 +171,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_INTERFACE_WITH_BUILDER, this);
         return;
     }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaOutput.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaOutput.java
index b88f24c..498510a 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaOutput.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaOutput.java
@@ -180,7 +180,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_INTERFACE_WITH_BUILDER, this);
     }
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaTypeDef.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaTypeDef.java
index 8717635..a8cc75b 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaTypeDef.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/javamodel/YangJavaTypeDef.java
@@ -175,7 +175,6 @@
     @Override
     public void generateCodeExit() throws IOException {
 
-        getTempJavaCodeFragmentFiles().setCurYangNode(this);
         getTempJavaCodeFragmentFiles().generateJavaFile(GENERATE_TYPEDEF_CLASS, this);
     }
 
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGenerator.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGenerator.java
index 299f5ac..42a55a6 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGenerator.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGenerator.java
@@ -78,10 +78,12 @@
      * @param file file
      * @param imports imports for the file
      * @param curNode current YANG node
+     * @param isAttrPresent  if any attribute is present or not
      * @return interface file
      * @throws IOException when fails to write in file
      */
-    public static File generateInterfaceFile(File file, List<String> imports, YangNode curNode) throws IOException {
+    public static File generateInterfaceFile(File file, List<String> imports, YangNode curNode, boolean isAttrPresent)
+            throws IOException {
 
         JavaFileInfo javaFileInfo = ((HasJavaFileInfo) curNode).getJavaFileInfo();
 
@@ -89,18 +91,19 @@
         String path = javaFileInfo.getBaseCodeGenPath() + javaFileInfo.getPackageFilePath();
 
         initiateJavaFileGeneration(file, className, INTERFACE_MASK, imports, path);
-
-        /**
-         * Add getter methods to interface file.
-         */
-        try {
+        if (isAttrPresent) {
             /**
-             * Getter methods.
+             * Add getter methods to interface file.
              */
-            insertDataIntoJavaFile(file, getDataFromTempFileHandle(GETTER_FOR_INTERFACE_MASK, curNode));
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while interface file generation");
+            try {
+                /**
+                 * Getter methods.
+                 */
+                insertDataIntoJavaFile(file, getDataFromTempFileHandle(GETTER_FOR_INTERFACE_MASK, curNode));
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while interface file generation");
+            }
         }
         return file;
     }
@@ -110,10 +113,12 @@
      *
      * @param file file
      * @param curNode current YANG node
+     * @param isAttrPresent  if any attribute is present or not
      * @return builder interface file
      * @throws IOException when fails to write in file
      */
-    public static File generateBuilderInterfaceFile(File file, YangNode curNode) throws IOException {
+    public static File generateBuilderInterfaceFile(File file, YangNode curNode, boolean isAttrPresent)
+            throws IOException {
 
         JavaFileInfo javaFileInfo = ((HasJavaFileInfo) curNode).getJavaFileInfo();
 
@@ -122,22 +127,22 @@
 
         initiateJavaFileGeneration(file, className, BUILDER_INTERFACE_MASK, null, path);
         List<String> methods = new ArrayList<>();
-
-        try {
-            /**
-             * Getter methods.
-             */
-            methods.add(FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(GETTER_FOR_INTERFACE_MASK, curNode));
-            /**
-             * Setter methods.
-             */
-            methods.add(NEW_LINE);
-            methods.add(FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(SETTER_FOR_INTERFACE_MASK, curNode));
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while builder interface file generation");
+        if (isAttrPresent) {
+            try {
+                /**
+                 * Getter methods.
+                 */
+                methods.add(FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(GETTER_FOR_INTERFACE_MASK, curNode));
+                /**
+                 * Setter methods.
+                 */
+                methods.add(NEW_LINE);
+                methods.add(FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(SETTER_FOR_INTERFACE_MASK, curNode));
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while builder interface file generation");
+            }
         }
-
         /**
          * Add build method to builder interface file.
          */
@@ -161,10 +166,12 @@
      * @param file file
      * @param imports imports for the file
      * @param curNode current YANG node
+     * @param isAttrPresent  if any attribute is present or not
      * @return builder class file
      * @throws IOException when fails to write in file
      */
-    public static File generateBuilderClassFile(File file, List<String> imports, YangNode curNode) throws IOException {
+    public static File generateBuilderClassFile(File file, List<String> imports, YangNode curNode,
+            boolean isAttrPresent) throws IOException {
 
         JavaFileInfo javaFileInfo = ((HasJavaFileInfo) curNode).getJavaFileInfo();
 
@@ -175,31 +182,34 @@
 
         List<String> methods = new ArrayList<>();
 
-        /**
-         * Add attribute strings.
-         */
-        try {
-            insertDataIntoJavaFile(file,
-                    NEW_LINE + FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(ATTRIBUTES_MASK, curNode));
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while builder class file generation");
-        }
-
-        try {
+        if (isAttrPresent) {
             /**
-             * Getter methods.
+             * Add attribute strings.
              */
-            methods.add(getDataFromTempFileHandle(GETTER_FOR_CLASS_MASK, curNode));
-            /**
-             * Setter methods.
-             */
-            methods.add(getDataFromTempFileHandle(SETTER_FOR_CLASS_MASK, curNode) + NEW_LINE);
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while builder class file generation");
-        }
+            try {
+                insertDataIntoJavaFile(file,
+                        NEW_LINE + FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(ATTRIBUTES_MASK, curNode));
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while builder class file generation");
+            }
 
+            try {
+                /**
+                 * Getter methods.
+                 */
+                methods.add(getDataFromTempFileHandle(GETTER_FOR_CLASS_MASK, curNode));
+                /**
+                 * Setter methods.
+                 */
+                methods.add(getDataFromTempFileHandle(SETTER_FOR_CLASS_MASK, curNode) + NEW_LINE);
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while builder class file generation");
+            }
+        } else {
+            insertDataIntoJavaFile(file, NEW_LINE);
+        }
         /**
          * Add default constructor and build method impl.
          */
@@ -221,10 +231,11 @@
      *
      * @param file file
      * @param curNode current YANG node
+     * @param isAttrPresent if any attribute is present or not
      * @return impl class file
      * @throws IOException when fails to write in file
      */
-    public static File generateImplClassFile(File file, YangNode curNode)
+    public static File generateImplClassFile(File file, YangNode curNode, boolean isAttrPresent)
             throws IOException {
 
         JavaFileInfo javaFileInfo = ((HasJavaFileInfo) curNode).getJavaFileInfo();
@@ -235,45 +246,48 @@
         initiateJavaFileGeneration(file, className, IMPL_CLASS_MASK, null, path);
 
         List<String> methods = new ArrayList<>();
+        if (isAttrPresent) {
+            /**
+             * Add attribute strings.
+             */
+            try {
+                insertDataIntoJavaFile(file,
+                        NEW_LINE + FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(ATTRIBUTES_MASK, curNode));
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while impl class file generation");
+            }
 
-        /**
-         * Add attribute strings.
-         */
-        try {
-            insertDataIntoJavaFile(file,
-                    NEW_LINE + FOUR_SPACE_INDENTATION + getDataFromTempFileHandle(ATTRIBUTES_MASK, curNode));
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while impl class file generation");
+            insertDataIntoJavaFile(file, NEW_LINE);
+            try {
+                /**
+                 * Getter methods.
+                 */
+                methods.add(getDataFromTempFileHandle(GETTER_FOR_CLASS_MASK, curNode));
+
+                /**
+                 * Hash code method.
+                 */
+                methods.add(getHashCodeMethodClose(getHashCodeMethodOpen() + partString(
+                        getDataFromTempFileHandle(HASH_CODE_IMPL_MASK, curNode).replace(NEW_LINE, EMPTY_STRING))));
+                /**
+                 * Equals method.
+                 */
+                methods.add(getEqualsMethodClose(
+                        getEqualsMethodOpen(className + IMPL) + getDataFromTempFileHandle(EQUALS_IMPL_MASK, curNode)));
+                /**
+                 * To string method.
+                 */
+                methods.add(getToStringMethodOpen() + getDataFromTempFileHandle(TO_STRING_IMPL_MASK, curNode)
+                        + getToStringMethodClose());
+
+            } catch (IOException e) {
+                throw new IOException("No data found in temporary java code fragment files for " + className
+                        + " while impl class file generation");
+            }
+        } else {
+            insertDataIntoJavaFile(file, NEW_LINE);
         }
-
-        insertDataIntoJavaFile(file, NEW_LINE);
-        try {
-            /**
-             * Getter methods.
-             */
-            methods.add(getDataFromTempFileHandle(GETTER_FOR_CLASS_MASK, curNode));
-            /**
-             * Hash code method.
-             */
-            methods.add(getHashCodeMethodClose(getHashCodeMethodOpen() + partString(
-                    getDataFromTempFileHandle(HASH_CODE_IMPL_MASK, curNode).replace(NEW_LINE, EMPTY_STRING))));
-            /**
-             * Equals method.
-             */
-            methods.add(getEqualsMethodClose(
-                    getEqualsMethodOpen(className + IMPL) + getDataFromTempFileHandle(EQUALS_IMPL_MASK, curNode)));
-            /**
-             * To string method.
-             */
-            methods.add(getToStringMethodOpen() + getDataFromTempFileHandle(TO_STRING_IMPL_MASK, curNode)
-                    + getToStringMethodClose());
-
-        } catch (IOException e) {
-            throw new IOException("No data found in temporary java code fragment files for " + className
-                    + " while impl class file generation");
-        }
-
         try {
             /**
              * Constructor.
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGeneratorUtils.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGeneratorUtils.java
index ad4dd0d..56f365d 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGeneratorUtils.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaFileGeneratorUtils.java
@@ -42,6 +42,7 @@
 import static org.onosproject.yangutils.translator.tojava.GeneratedTempFileType.SETTER_FOR_INTERFACE_MASK;
 import static org.onosproject.yangutils.translator.tojava.GeneratedTempFileType.TO_STRING_IMPL_MASK;
 import static org.onosproject.yangutils.translator.tojava.utils.JavaCodeSnippetGen.getJavaClassDefStart;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getJavaPackageFromPackagePath;
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
 import static org.onosproject.yangutils.utils.UtilConstants.ORG;
 import static org.onosproject.yangutils.utils.UtilConstants.PACKAGE;
@@ -53,7 +54,6 @@
 import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.BUILDER_INTERFACE;
 import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.IMPL_CLASS;
 import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.INTERFACE;
-import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.convertPathToPkg;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.insertDataIntoJavaFile;
 
 /**
@@ -192,7 +192,7 @@
 
         if (javaPkg.contains(ORG)) {
             String[] strArray = javaPkg.split(ORG);
-            javaPkg = ORG + convertPathToPkg(strArray[1]);
+            javaPkg = ORG + getJavaPackageFromPackagePath(strArray[1]);
         }
         if (importsList != null) {
             if (!importsList.isEmpty()) {
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntax.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntax.java
index e89a8a9..5ea5f1e 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntax.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntax.java
@@ -32,8 +32,10 @@
 import static org.onosproject.yangutils.utils.UtilConstants.QUOTES;
 import static org.onosproject.yangutils.utils.UtilConstants.REGEX_FOR_FIRST_DIGIT;
 import static org.onosproject.yangutils.utils.UtilConstants.REGEX_WITH_SPECIAL_CHAR;
+import static org.onosproject.yangutils.utils.UtilConstants.REVISION_PREFIX;
 import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
 import static org.onosproject.yangutils.utils.UtilConstants.UNDER_SCORE;
+import static org.onosproject.yangutils.utils.UtilConstants.VERSION_PREFIX;
 
 /**
  * Utility Class for translating the name from YANG to java convention.
@@ -121,7 +123,7 @@
      */
     private static String getYangVersion(byte ver) {
 
-        return "v" + ver;
+        return VERSION_PREFIX + ver;
     }
 
     /**
@@ -154,7 +156,7 @@
 
         String[] revisionArr = date.split(HYPHEN);
 
-        String rev = "rev";
+        String rev = REVISION_PREFIX;
         rev = rev + revisionArr[INDEX_ZERO];
 
         if (Integer.parseInt(revisionArr[INDEX_ONE]) <= MAX_MONTHS
@@ -251,7 +253,7 @@
      * @param yangIdentifier identifier in YANG file.
      * @return corresponding java identifier
      */
-    public static String getLowerCase(String yangIdentifier) {
+    public static String getSmallCase(String yangIdentifier) {
 
         return yangIdentifier.substring(0, 1).toLowerCase() + yangIdentifier.substring(1);
     }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGenerator.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGenerator.java
index f1c17db..4eeadf6 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGenerator.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGenerator.java
@@ -20,7 +20,7 @@
 
 import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getCamelCase;
 import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getCaptialCase;
-import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getLowerCase;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getSmallCase;
 import static org.onosproject.yangutils.utils.UtilConstants.ADD_STRING;
 import static org.onosproject.yangutils.utils.UtilConstants.AND;
 import static org.onosproject.yangutils.utils.UtilConstants.BOOLEAN_DATA_TYPE;
@@ -113,7 +113,7 @@
     public static String getGetterString(JavaAttributeInfo attr) {
 
         String returnType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         return getJavaDoc(GETTER_METHOD, attributeName, attr.isListAttr())
                 + getGetterForInterface(attributeName, returnType, attr.isListAttr());
@@ -129,7 +129,7 @@
     public static String getSetterString(JavaAttributeInfo attr, String className) {
 
         String attrType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         return getJavaDoc(SETTER_METHOD, attributeName, attr.isListAttr())
                 + getSetterForInterface(attributeName, attrType, className, attr.isListAttr());
@@ -168,7 +168,7 @@
     public static String getTypeDefConstructor(JavaAttributeInfo attr, String className) {
 
         String attrQuaifiedType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         if (!attr.isListAttr()) {
             return getTypeDefConstructorString(attrQuaifiedType, attributeName, className);
@@ -225,7 +225,7 @@
     public static String getGetterForClass(JavaAttributeInfo attr) {
 
         String attrQuaifiedType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         if (!attr.isListAttr()) {
             return getGetter(attrQuaifiedType, attributeName);
@@ -258,7 +258,7 @@
     public static String getSetterForClass(JavaAttributeInfo attr, String className) {
 
         String attrQuaifiedType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
         if (!attr.isListAttr()) {
             return getSetter(className, attributeName, attrQuaifiedType);
         }
@@ -292,7 +292,7 @@
     public static String getSetterForTypeDefClass(JavaAttributeInfo attr) {
 
         String attrQuaifiedType = getReturnType(attr);
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
         return getTypeDefSetter(attrQuaifiedType, attributeName);
     }
 
@@ -445,7 +445,7 @@
      */
     public static String getConstructor(String yangName, JavaAttributeInfo attr) {
 
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         String constructor = EIGHT_SPACE_INDENTATION + THIS + PERIOD + getCamelCase(attributeName) + SPACE + EQUAL
                 + SPACE + BUILDER.toLowerCase() + OBJECT + PERIOD + GET_METHOD_PREFIX
@@ -513,7 +513,7 @@
      */
     public static String getToStringMethod(JavaAttributeInfo attr) {
 
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         return TWELVE_SPACE_INDENTATION + PERIOD + ADD_STRING + OPEN_PARENTHESIS + QUOTES + attributeName + QUOTES
                 + COMMA + SPACE + attributeName + CLOSE_PARENTHESIS;
@@ -554,7 +554,7 @@
      */
     public static String getHashCodeMethod(JavaAttributeInfo attr) {
 
-        return getLowerCase(attr.getAttributeName()) + COMMA + SPACE;
+        return getSmallCase(attr.getAttributeName()) + COMMA + SPACE;
     }
 
     /**
@@ -621,7 +621,7 @@
      */
     public static String getEqualsMethod(JavaAttributeInfo attr) {
 
-        String attributeName = getLowerCase(attr.getAttributeName());
+        String attributeName = getSmallCase(attr.getAttributeName());
 
         return SIXTEEN_SPACE_INDENTATION + SPACE + OBJECT_STRING + SUFFIX_S + PERIOD + EQUALS_STRING + OPEN_PARENTHESIS
                 + attributeName + COMMA + SPACE + OTHER + PERIOD + attributeName + CLOSE_PARENTHESIS + SPACE + AND
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/TempDataStoreTypes.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/TempDataStoreTypes.java
deleted file mode 100644
index 0344672..0000000
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/tojava/utils/TempDataStoreTypes.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * 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.translator.tojava.utils;
-
-/**
- * Data Store types.
- */
-public enum TempDataStoreTypes {
-
-    /**
-     * Getter methods for interfaces.
-     */
-    GETTER_METHODS,
-
-    /**
-     * Getter methods impl for classes.
-     */
-    GETTER_METHODS_IMPL,
-
-    /**
-     * Setter methods for interfaces.
-     */
-    SETTER_METHODS,
-
-    /**
-     * Setter methods impl for classes.
-     */
-    SETTER_METHODS_IMPL,
-
-    /**
-     * Constructor for impl class.
-     */
-    CONSTRUCTOR,
-
-    /**
-     * Attributes.
-     */
-    ATTRIBUTE,
-
-    /**
-     * TypeDef.
-     */
-    TYPE_DEF,
-
-    /**
-     * ToString method.
-     */
-    TO_STRING,
-
-    /**
-     * HashCode method.
-     */
-    HASH_CODE,
-
-    /**
-     * Equals method.
-     */
-    EQUALS
-}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
index 9f52cb7..369b08a 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
@@ -32,118 +32,405 @@
     }
 
     /**
-     * For java-docs.
+     * JavaDocs for impl class.
      */
     public static final String IMPL_CLASS_JAVA_DOC = " * Provides the implementation of ";
+
+    /**
+     * JavaDocs for builder class.
+     */
     public static final String BUILDER_CLASS_JAVA_DOC = " * Provides the builder implementation of ";
+
+    /**
+     * JavaDocs for interface class.
+     */
     public static final String INTERFACE_JAVA_DOC = " * Abstraction of an entity which provides functionalities of ";
+
+    /**
+     * JavaDocs for builder interface class.
+     */
     public static final String BUILDER_INTERFACE_JAVA_DOC = " * Builder for ";
+
+    /**
+     * JavaDocs for package info class.
+     */
     public static final String PACKAGE_INFO_JAVADOC = " * Implementation of YANG file ";
+
+    /**
+     * JavaDocs's first line.
+     */
     public static final String JAVA_DOC_FIRST_LINE = "/**\n";
+
+    /**
+     * JavaDocs's last line.
+     */
     public static final String JAVA_DOC_END_LINE = " */\n";
+
+    /**
+     * JavaDocs's param annotation.
+     */
     public static final String JAVA_DOC_PARAM = " * @param ";
+
+    /**
+     * JavaDocs's return annotation.
+     */
     public static final String JAVA_DOC_RETURN = " * @return ";
+
+    /**
+     * JavaDocs's throw annotation.
+     */
     public static final String JAVA_DOC_THROWS = " * @throws ";
+
+    /**
+     * JavaDocs's description for setter method.
+     */
     public static final String JAVA_DOC_SETTERS = " * Returns the builder object of ";
+
+    /**
+     * JavaDocs's description for OF method.
+     */
     public static final String JAVA_DOC_OF = " * Returns the object of ";
+
+    /**
+     * JavaDocs's description for typedef' setter method.
+     */
     public static final String JAVA_DOC_SETTERS_COMMON = " * Sets the value of ";
+
+    /**
+     * JavaDocs's description for getter method.
+     */
     public static final String JAVA_DOC_GETTERS = " * Returns the attribute ";
+
+    /**
+     * JavaDocs's description for default constructor.
+     */
     public static final String JAVA_DOC_DEFAULT_CONSTRUCTOR = " * Default Constructor.\n";
+
+    /**
+     * JavaDocs's description for constructor.
+     */
     public static final String JAVA_DOC_CONSTRUCTOR = " * Construct the object of ";
+
+    /**
+     * JavaDocs's description for build method.
+     */
     public static final String JAVA_DOC_BUILD = " * Builds object of ";
+
+    /**
+     * JavaDocs's return statement for build method.
+     */
     public static final String JAVA_DOC_BUILD_RETURN = "object of ";
 
     /**
-     * Basic requirements.
+     * JavaDocs's statement for builder object.
+     */
+    public static final String BUILDER_OBJECT = "builder object of ";
+
+    /**
+     * Static attribute for new line.
      */
     public static final String NEW_LINE = "\n";
+
+    /**
+     * Static attribute for multiple new line.
+     */
     public static final String MULTIPLE_NEW_LINE = "\n\n";
+
+    /**
+     * Static attribute for empty line.
+     */
     public static final String EMPTY_STRING = "";
-    public static final String NEW_LINE_ESTRIC = " *\n";
+
+    /**
+     * Static attribute for new line with asterisk.
+     */
+    public static final String NEW_LINE_ASTERISK = " *\n";
+
+    /**
+     * Static attribute for period.
+     */
     public static final String PERIOD = ".";
+
+    /**
+     * Static attribute for colan.
+     */
     public static final String COLAN = ":";
+
+    /**
+     * Static attribute for underscore.
+     */
     public static final String UNDER_SCORE = "_";
+
+    /**
+     * Static attribute for semi-colan.
+     */
     public static final String SEMI_COLAN = ";";
+
+    /**
+     * Static attribute for hyphen.
+     */
     public static final String HYPHEN = "-";
+
+    /**
+     * Static attribute for space.
+     */
     public static final String SPACE = " ";
+
+    /**
+     * Static attribute for tab.
+     */
     public static final String TAB = "\t";
+
+    /**
+     * Static attribute for new line.
+     */
     public static final String EQUAL = "=";
+
+    /**
+     * Static attribute for slash syntax.
+     */
     public static final String SLASH = File.separator;
+
+    /**
+     * Static attribute for add syntax.
+     */
     public static final String ADD = "+";
+
+    /**
+     * Static attribute for asterisk.
+     */
     public static final String ASTERISK = "*";
+
+    /**
+     * Static attribute for at.
+     */
     public static final String AT = "@";
+
+    /**
+     * Static attribute for quotes.
+     */
     public static final String QUOTES = "\"";
+
+    /**
+     * Static attribute for ampersand.
+     */
     public static final String AND = "&";
+
+    /**
+     * Static attribute for comma.
+     */
     public static final String COMMA = ",";
+
+    /**
+     * Static attribute for add syntax.
+     */
     public static final String ADD_STRING = "add";
+
+    /**
+     * Static attribute for check not null syntax.
+     */
     public static final String CHECK_NOT_NULL_STRING = "checkNotNull";
+
+    /**
+     * Static attribute for hash code syntax.
+     */
     public static final String HASH_CODE_STRING = "hashCode";
+
+    /**
+     * Static attribute for equals syntax.
+     */
     public static final String EQUALS_STRING = "equals";
+
+    /**
+     * Static attribute for object.
+     */
     public static final String OBJECT_STRING = "Object";
+
+    /**
+     * Static attribute for instance of syntax.
+     */
     public static final String INSTANCE_OF = " instanceof ";
 
+    /**
+     * Static attribute for value syntax.
+     */
     public static final String VALUE = "value";
+
+    /**
+     * Static attribute for suffix s.
+     */
     public static final String SUFFIX_S = "s";
 
+    /**
+     * Static attribute for if.
+     */
     public static final String IF = "if";
+
+    /**
+     * Static attribute for for.
+     */
     public static final String FOR = "for";
+
+    /**
+     * Static attribute for while.
+     */
     public static final String WHILE = "while";
+
+    /**
+     * Static attribute for of.
+     */
     public static final String OF = "of";
+
+    /**
+     * Static attribute for other.
+     */
     public static final String OTHER = "other";
+
+    /**
+     * Static attribute for obj syntax.
+     */
     public static final String OBJ = "obj";
+
+    /**
+     * Static attribute for hash syntax.
+     */
     public static final String HASH = "hash";
+
+    /**
+     * Static attribute for to syntax.
+     */
     public static final String TO = "to";
 
+    /**
+     * Static attribute for true syntax.
+     */
     public static final String TRUE = "true";
+
+    /**
+     * Static attribute for false syntax.
+     */
     public static final String FALSE = "false";
+
+    /**
+     * Static attribute for org.
+     */
     public static final String ORG = "org";
+
+    /**
+     * Static attribute for temp.
+     */
     public static final String TEMP = "temp";
+
+    /**
+     * Static attribute for YANG file directory.
+     */
     public static final String YANG_RESOURCES = "yang/resources";
 
     /**
-     * For brackets.
+     * Static attribute for diamond close bracket syntax.
      */
     public static final String DIAMOND_OPEN_BRACKET = "<";
+
+    /**
+     * Static attribute for diamond close bracket syntax.
+     */
     public static final String DIAMOND_CLOSE_BRACKET = ">";
+
+    /**
+     * Static attribute for square open bracket syntax.
+     */
     public static final String SQUARE_OPEN_BRACKET = "[";
+
+    /**
+     * Static attribute for square close bracket syntax.
+     */
     public static final String SQUARE_CLOSE_BRACKET = "]";
+
+    /**
+     * Static attribute for open parenthesis syntax.
+     */
     public static final String OPEN_PARENTHESIS = "(";
+
+    /**
+     * Static attribute for close parenthesis syntax.
+     */
     public static final String CLOSE_PARENTHESIS = ")";
+
+    /**
+     * Static attribute for open curly bracket syntax.
+     */
     public static final String OPEN_CURLY_BRACKET = "{";
+
+    /**
+     * Static attribute for close curly bracket syntax.
+     */
     public static final String CLOSE_CURLY_BRACKET = "}";
 
     /**
-     * For methods.
+     * Static attribute for getter method prefix.
      */
     public static final String GET_METHOD_PREFIX = "get";
+
+    /**
+     * Static attribute for setter method prefix.
+     */
     public static final String SET_METHOD_PREFIX = "set";
 
     /**
-     * For indentation.
+     * Static attribute for four space indentation.
      */
     public static final String FOUR_SPACE_INDENTATION = "    ";
+
+    /**
+     * Static attribute for eight space indentation.
+     */
     public static final String EIGHT_SPACE_INDENTATION = FOUR_SPACE_INDENTATION + FOUR_SPACE_INDENTATION;
+
+    /**
+     * Static attribute for twelve space indentation.
+     */
     public static final String TWELVE_SPACE_INDENTATION = FOUR_SPACE_INDENTATION + EIGHT_SPACE_INDENTATION;
+
+    /**
+     * Static attribute for sixteen space indentation.
+     */
     public static final String SIXTEEN_SPACE_INDENTATION = EIGHT_SPACE_INDENTATION + EIGHT_SPACE_INDENTATION;
 
     /**
-     * For directories.
+     * Static attribute for generated code path.
      */
     public static final String YANG_GEN_DIR = "src/main/java/";
+
+    /**
+     * Static attribute for base package.
+     */
     public static final String DEFAULT_BASE_PKG = "org.onosproject.yang.gen";
+
+    /**
+     * Static attribute for YANG date prefix.
+     */
     public static final String REVISION_PREFIX = "rev";
+
+    /**
+     * Static attribute for YANG version perifx.
+     */
     public static final String VERSION_PREFIX = "v";
 
     /**
-     * For class modifiers.
+     * Static attribute for private modifier.
      */
     public static final String PRIVATE = "private";
-    public static final String PUBLIC = "public";
-    public static final String PROTECTED = "protected";
 
     /**
-     * For data types.
+     * Static attribute for public modifier.
      */
+    public static final String PUBLIC = "public";
+
+    /**
+     * Static attribute for protected modifier.
+     */
+    public static final String PROTECTED = "protected";
+
     /**
      * Void java type.
      */
@@ -231,71 +518,230 @@
     /**
      * List of keywords in java, this is used for checking if the input does not contain these keywords.
      */
-    public static final List JAVA_KEY_WORDS = Arrays.asList("abstract", "assert", "boolean", "break", "byte", "case",
-            "catch", "char", "class", "const", "continue", "default", "do", "double", "else", "extends", "false",
-            "final", "finally", "float", "for", "goto", "if", "implements", "import", "instanceof", "int", "interface",
-            "long", "native", "new", "null", "package", "private", "protected", "public", "return", "short", "static",
-            "strictfp", "super", "switch", "synchronized", "this", "throw", "throws", "transient", "true", "try",
-            "void", "volatile", "while");
+    public static final List<String> JAVA_KEY_WORDS = Arrays.asList(
+            "abstract", "assert", "boolean", "break", "byte", "case", "catch", "char", "class", "const", "continue",
+            "default", "do", "double", "else", "extends", "false", "final", "finally", "float", "for", "goto", "if",
+            "implements", "import", "instanceof", "int", "interface", "long", "native", "new", "null", "package",
+            "private", "protected", "public", "return", "short", "static", "strictfp", "super", "switch",
+            "synchronized", "this", "throw", "throws", "transient", "true", "try", "void", "volatile", "while");
 
     /**
-     * Defining regular expression.
+     * Static attribute for regex for special char.
      */
     public static final String REGEX_WITH_SPECIAL_CHAR = "[ : / - @ $ # ' * + , ; = ]+";
+
+    /**
+     * Static attribute for regex for digits.
+     */
     public static final String REGEX_FOR_FIRST_DIGIT = "\\d.*";
 
     /**
-     * For identifiers.
+     * Static attribute for class syntax.
      */
     public static final String CLASS = "class";
-    public static final String BUILDER = "Builder";
-    public static final String BUILDER_OBJECT = "builder object of ";
-    public static final String INTERFACE = "interface";
-    public static final String ENUM = "enum";
-    public static final String STATIC = "static";
-    public static final String FINAL = "final";
-    public static final String PACKAGE = "package";
-    public static final String IMPORT = "import ";
-    public static final String NULL = "null";
-    public static final String RETURN = "return";
-    public static final String NEW = "new";
-    public static final String THIS = "this";
-    public static final String IMPLEMENTS = "implements";
-    public static final String EXTEND = "extends";
-    public static final String IMPL = "Impl";
-    public static final String BUILD = "build";
-    public static final String OBJECT = "Object";
-    public static final String OVERRIDE = "@Override";
-    public static final String CHILDREN = "'s children";
 
     /**
-     * For collections.
+     * Static attribute for builder syntax.
+     */
+    public static final String BUILDER = "Builder";
+
+    /**
+     * Static attribute for interface syntax.
+     */
+    public static final String INTERFACE = "interface";
+
+    /**
+     * Static attribute for enum syntax.
+     */
+    public static final String ENUM = "enum";
+
+    /**
+     * Static attribute for static syntax.
+     */
+    public static final String STATIC = "static";
+
+    /**
+     * Static attribute for final syntax.
+     */
+    public static final String FINAL = "final";
+
+    /**
+     * Static attribute for package syntax.
+     */
+    public static final String PACKAGE = "package";
+
+    /**
+     * Static attribute for import syntax.
+     */
+    public static final String IMPORT = "import ";
+
+    /**
+     * Static attribute for null syntax.
+     */
+    public static final String NULL = "null";
+
+    /**
+     * Static attribute for return syntax.
+     */
+    public static final String RETURN = "return";
+
+    /**
+     * Static attribute for java new syntax.
+     */
+    public static final String NEW = "new";
+
+    /**
+     * Static attribute for this syntax.
+     */
+    public static final String THIS = "this";
+
+    /**
+     * Static attribute for implements syntax.
+     */
+    public static final String IMPLEMENTS = "implements";
+
+    /**
+     * Static attribute for extends syntax.
+     */
+    public static final String EXTEND = "extends";
+
+    /**
+     * Static attribute for impl syntax.
+     */
+    public static final String IMPL = "Impl";
+
+    /**
+     * Static attribute for build method syntax.
+     */
+    public static final String BUILD = "build";
+
+    /**
+     * Static attribute for object.
+     */
+    public static final String OBJECT = "Object";
+
+    /**
+     * Static attribute for override annotation.
+     */
+    public static final String OVERRIDE = "@Override";
+
+    /**
+     * Static attribute for new line.
      */
     public static final String COLLECTION_IMPORTS = "java.util";
+
+    /**
+     * Static attribute for more object import package.
+     */
     public static final String GOOGLE_MORE_OBJECT_IMPORT_PKG = "com.google.common.base";
+
+    /**
+     * Static attribute for more object import class.
+     */
     public static final String GOOGLE_MORE_OBJECT_IMPORT_CLASS = "MoreObjects;\n";
+
+    /**
+     * Static attribute for to string method.
+     */
     public static final String GOOGLE_MORE_OBJECT_METHOD_STRING = " MoreObjects.toStringHelper(getClass())";
+
+    /**
+     * Static attribute for java utilities import package.
+     */
     public static final String JAVA_UTIL_OBJECTS_IMPORT_PKG = "java.util";
+
+    /**
+     * Static attribute for java utilities objects import class.
+     */
     public static final String JAVA_UTIL_OBJECTS_IMPORT_CLASS = "Objects;\n";
+
+    /**
+     * Static attribute for abstract collection.
+     */
     public static final String ABSTRACT_COLLECTION = "AbstractCollection";
 
+    /**
+     * Static attribute for list.
+     */
     public static final String LIST = "List";
+
+    /**
+     * Static attribute for linked list.
+     */
     public static final String LINKED_LIST = "LinkedList";
+
+    /**
+     * Static attribute for array list.
+     */
     public static final String ARRAY_LIST = "ArrayList";
+
+    /**
+     * Static attribute for abstract list.
+     */
     public static final String ABSTRACT_LIST = "AbstractList";
+
+    /**
+     * Static attribute for abstract sequential list.
+     */
     public static final String ABSTRACT_SEQUENTAIL_LIST = "AbstractSequentialList";
 
+    /**
+     * Static attribute for set.
+     */
     public static final String SET = "Set";
+
+    /**
+     * Static attribute for hash set.
+     */
     public static final String HASH_SET = "HashSet";
+
+    /**
+     * Static attribute for abstract set.
+     */
     public static final String ABSTRACT_SET = "AbstractSet";
+
+    /**
+     * Static attribute for linked has set.
+     */
     public static final String LINKED_HASH_SET = "LinkedHashSet";
+
+    /**
+     * Static attribute for tree set.
+     */
     public static final String TREE_SET = "TreeSet";
 
+    /**
+     * Static attribute for map.
+     */
     public static final String MAP = "Map";
+
+    /**
+     * Static attribute for abstract map.
+     */
     public static final String ABSTRACT_MAP = "AbstractMap";
+
+    /**
+     * Static attribute for hash map.
+     */
     public static final String HASH_MAP = "HashMap";
+
+    /**
+     * Static attribute for tree map.
+     */
     public static final String TREE_MAP = "TreeMap";
+
+    /**
+     * Static attribute for concurrent map.
+     */
     public static final String CONCURRENT_MAP = "ConcurrentMap";
+
+    /**
+     * Static attribute for eventually consistent map.
+     */
     public static final String EVENTUALLY_CONSISTENT_MAP = "EventuallyConsitentMap";
+
+    /**
+     * Static attribute for stack syntax.
+     */
     public static final String STACK = "stack";
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtil.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtil.java
index 3c312fb..a31bb7f 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtil.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtil.java
@@ -23,6 +23,8 @@
 import java.io.IOException;
 import java.io.PrintWriter;
 
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getJavaPackageFromPackagePath;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getPackageDirPathFromJavaJPackage;
 import static org.onosproject.yangutils.utils.UtilConstants.EIGHT_SPACE_INDENTATION;
 import static org.onosproject.yangutils.utils.UtilConstants.EMPTY_STRING;
 import static org.onosproject.yangutils.utils.UtilConstants.FOUR_SPACE_INDENTATION;
@@ -31,8 +33,6 @@
 import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
 import static org.onosproject.yangutils.utils.UtilConstants.SPACE;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.addPackageInfo;
-import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.convertPathToPkg;
-import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.convertPkgToPath;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.createDirectories;
 
 /**
@@ -54,7 +54,7 @@
      */
     public static boolean doesPackageExist(String pkg) {
 
-        File pkgDir = new File(convertPkgToPath(pkg));
+        File pkgDir = new File(getPackageDirPathFromJavaJPackage(pkg));
         File pkgWithFile = new File(pkgDir + SLASH + "package-info.java");
         if (pkgDir.exists() && pkgWithFile.isFile()) {
             return true;
@@ -74,7 +74,7 @@
         if (!doesPackageExist(pkg)) {
             try {
                 File pack = createDirectories(pkg);
-                addPackageInfo(pack, pkgInfo, convertPathToPkg(pkg));
+                addPackageInfo(pack, pkgInfo, getJavaPackageFromPackagePath(pkg));
             } catch (IOException e) {
                 throw new IOException("failed to create package-info file");
             }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/JavaDocGen.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/JavaDocGen.java
index 2c9c242..c3ff0a3 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/JavaDocGen.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/JavaDocGen.java
@@ -41,7 +41,7 @@
 import static org.onosproject.yangutils.utils.UtilConstants.JAVA_DOC_SETTERS_COMMON;
 import static org.onosproject.yangutils.utils.UtilConstants.LIST;
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
-import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE_ESTRIC;
+import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE_ASTERISK;
 import static org.onosproject.yangutils.utils.UtilConstants.OBJECT;
 import static org.onosproject.yangutils.utils.UtilConstants.OF;
 import static org.onosproject.yangutils.utils.UtilConstants.PACKAGE_INFO_JAVADOC;
@@ -141,7 +141,7 @@
      */
     public static String getJavaDoc(JavaDocType type, String name, boolean isList) {
 
-        name = JavaIdentifierSyntax.getLowerCase(JavaIdentifierSyntax.getCamelCase(name));
+        name = JavaIdentifierSyntax.getSmallCase(JavaIdentifierSyntax.getCamelCase(name));
         String javaDoc = UtilConstants.EMPTY_STRING;
         if (type.equals(JavaDocType.IMPL_CLASS)) {
             javaDoc = generateForImplClass(name);
@@ -183,7 +183,7 @@
     private static String generateForGetters(String attribute, boolean isList) {
 
         String getter = NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION
-                + JAVA_DOC_GETTERS + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC
+                + JAVA_DOC_GETTERS + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_RETURN;
         if (isList) {
             String listAttribute = LIST.toLowerCase() + SPACE + OF + SPACE;
@@ -206,7 +206,7 @@
     private static String generateForSetters(String attribute, boolean isList) {
 
         String setter = NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION
-                + JAVA_DOC_SETTERS + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC
+                + JAVA_DOC_SETTERS + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_PARAM + attribute + SPACE;
         if (isList) {
             String listAttribute = LIST.toLowerCase() + SPACE + OF + SPACE;
@@ -228,7 +228,7 @@
     private static String generateForOf(String attribute) {
 
         return NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_OF
-                + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC + FOUR_SPACE_INDENTATION
+                + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK + FOUR_SPACE_INDENTATION
                 + JAVA_DOC_PARAM + VALUE + SPACE + VALUE + SPACE + OF + SPACE + attribute + NEW_LINE
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_RETURN + OBJECT + SPACE + OF + SPACE + attribute + NEW_LINE
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_END_LINE;
@@ -243,7 +243,7 @@
     private static String generateForTypeDefSetter(String attribute) {
 
         return (NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION
-                + JAVA_DOC_SETTERS_COMMON + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC
+                + JAVA_DOC_SETTERS_COMMON + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_PARAM + VALUE + SPACE + VALUE + SPACE + OF + SPACE + attribute
                 + NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_END_LINE);
     }
@@ -257,7 +257,7 @@
     private static String generateForTypeDefConstructor(String attribute) {
 
         return (NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_CONSTRUCTOR
-                + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC + FOUR_SPACE_INDENTATION
+                + attribute + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK + FOUR_SPACE_INDENTATION
                 + JAVA_DOC_PARAM + VALUE + SPACE + VALUE + SPACE + OF + SPACE + attribute + NEW_LINE
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_END_LINE);
     }
@@ -341,8 +341,8 @@
 
         return NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_CONSTRUCTOR + className + IMPL + PERIOD + NEW_LINE
-                + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC + FOUR_SPACE_INDENTATION + JAVA_DOC_PARAM
-                + BUILDER.toLowerCase() + OBJECT + SPACE + BUILDER_OBJECT + SPACE + className + NEW_LINE
+                + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK + FOUR_SPACE_INDENTATION + JAVA_DOC_PARAM
+                + BUILDER.toLowerCase() + OBJECT + SPACE + BUILDER_OBJECT + className + NEW_LINE
                 + FOUR_SPACE_INDENTATION + JAVA_DOC_END_LINE;
     }
 
@@ -355,7 +355,7 @@
     private static String generateForBuild(String buildName) {
 
         return NEW_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_FIRST_LINE + FOUR_SPACE_INDENTATION + JAVA_DOC_BUILD
-                + buildName + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ESTRIC + FOUR_SPACE_INDENTATION
+                + buildName + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION + NEW_LINE_ASTERISK + FOUR_SPACE_INDENTATION
                 + JAVA_DOC_RETURN + JAVA_DOC_BUILD_RETURN + buildName + PERIOD + NEW_LINE + FOUR_SPACE_INDENTATION
                 + JAVA_DOC_END_LINE;
     }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangFileScanner.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangFileScanner.java
index 9de5358..bdf911a 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangFileScanner.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangFileScanner.java
@@ -45,7 +45,7 @@
      * @throws IOException when files get deleted while performing the
      *             operations
      */
-    public static List<String> getJavaFiles(String root) throws NullPointerException, IOException {
+    public static List<String> getJavaFiles(String root) throws IOException {
 
         return getFiles(root, JAVA_FILE_EXTENTION);
     }
@@ -59,7 +59,7 @@
      * @throws IOException when files get deleted while performing the
      *             operations
      */
-    public static List<String> getYangFiles(String root) throws NullPointerException, IOException {
+    public static List<String> getYangFiles(String root) throws IOException {
 
         return getFiles(root, YANG_FILE_EXTENTION);
     }
@@ -73,7 +73,7 @@
      * @throws NullPointerException when no file is there
      * @throws IOException when files get deleted while performing the operations
      */
-    public static List<String> getFiles(String root, String extension) throws NullPointerException, IOException {
+    public static List<String> getFiles(String root, String extension) throws IOException {
 
         List<String> store = new LinkedList<>();
         Stack<String> stack = new Stack<>();
@@ -100,8 +100,8 @@
                 }
             }
             return store;
-        } catch (NullPointerException e) {
-            throw new IOException("NullPointerException occured");
+        } catch (IOException e) {
+            throw new IOException("No File found of " + extension + " extension in " + root + " directory.");
         }
     }
 }
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
index 866ff97..4a9c4d7 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
@@ -36,7 +36,6 @@
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
 import static org.onosproject.yangutils.utils.UtilConstants.ORG;
 import static org.onosproject.yangutils.utils.UtilConstants.PACKAGE;
-import static org.onosproject.yangutils.utils.UtilConstants.PERIOD;
 import static org.onosproject.yangutils.utils.UtilConstants.SEMI_COLAN;
 import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
 import static org.onosproject.yangutils.utils.UtilConstants.SPACE;
@@ -294,26 +293,4 @@
             throw new IOException("Failed to insert in " + file + "file");
         }
     }
-
-    /**
-     * Convert directory path in java package format.
-     *
-     * @param path directory path
-     * @return java package
-     */
-    public static String convertPathToPkg(String path) {
-
-        return path.replace(SLASH, PERIOD);
-    }
-
-    /**
-     * Convert java package in directory path format.
-     *
-     * @param pkg java package
-     * @return directory path
-     */
-    public static String convertPkgToPath(String pkg) {
-
-        return pkg.replace(PERIOD, SLASH);
-    }
 }