diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java
new file mode 100644
index 0000000..41b2418
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java
@@ -0,0 +1,112 @@
+/*
+ * 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.parserutils;
+
+import org.antlr.v4.runtime.ParserRuleContext;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.regex.Pattern;
+import org.onosproject.yangutils.utils.YangConstructType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+
+/**
+ * It's a utility for listener.
+ */
+public final class ListenerUtil {
+    private static final Pattern IDENTIFIER_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_.-]*");
+    private static final String PLUS = "+";
+    private static final int IDENTIFIER_LENGTH = 64;
+
+    /**
+     * Creates a new listener util.
+     */
+    private ListenerUtil() {
+    }
+
+    /**
+     * Removes doubles quotes and concatenates if string has plus symbol.
+     *
+     * @param yangStringData string from yang file
+     * @return concatenated string after removing double quotes
+     */
+    public static String removeQuotesAndHandleConcat(String yangStringData) {
+
+        yangStringData = yangStringData.replace("\"", "");
+        String[] tmpData = yangStringData.split(Pattern.quote(PLUS));
+        StringBuilder builder = new StringBuilder();
+        for (String yangString : tmpData) {
+            builder.append(yangString);
+        }
+        return builder.toString();
+    }
+
+    /**
+     * Validates identifier and returns concatenated string if string contains plus symbol.
+     *
+     * @param identifier string from yang file
+     * @param yangConstruct yang construct for creating error message
+     * @param ctx yang construct's context to get the line number and character position
+     * @return concatenated string after removing double quotes
+     */
+    public static String getValidIdentifier(String identifier, YangConstructType yangConstruct, ParserRuleContext ctx) {
+
+        String identifierString = removeQuotesAndHandleConcat(identifier);
+        ParserException parserException;
+
+        if (identifierString.length() > IDENTIFIER_LENGTH) {
+            parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(yangConstruct) + " name " + identifierString + " is " +
+                    "greater than 64 characters.");
+        } else if (!IDENTIFIER_PATTERN.matcher(identifierString).matches()) {
+            parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(yangConstruct) + " name " + identifierString + " is not " +
+                    "valid.");
+        } else {
+            return identifierString;
+        }
+
+        parserException.setLine(ctx.getStart().getLine());
+        parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+        throw parserException;
+    }
+
+    /**
+     * Validates the revision date.
+     *
+     * @param dateToValidate input revision date
+     * @return validation result, true for success, false for failure
+     */
+    public static boolean isDateValid(String dateToValidate) {
+
+        if (dateToValidate == null || !dateToValidate.matches("[0-9]{4}-[0-9]{2}-[0-9]{2}")) {
+            return false;
+        }
+
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+        sdf.setLenient(false);
+
+        try {
+            //if not valid, it will throw ParseException
+            sdf.parse(dateToValidate);
+        } catch (ParseException e) {
+            return false;
+        }
+
+        return true;
+    }
+}
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