diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java
new file mode 100644
index 0000000..0daa5d5
--- /dev/null
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java
@@ -0,0 +1,120 @@
+/*
+ * 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;
+
+import org.junit.Test;
+import org.onosproject.yangutils.translator.GeneratedFileType;
+import org.onosproject.yangutils.translator.tojava.GeneratedMethodTypes;
+import org.onosproject.yangutils.translator.tojava.TraversalType;
+import org.onosproject.yangutils.utils.UtilConstants;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import static org.junit.Assert.assertNotNull;
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Unit tests for class definition generator for generated files.
+ */
+public final class ClassDefinitionGeneratorTest {
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException if any security violation is observed.
+     * @throws NoSuchMethodException if when the method is not found.
+     * @throws IllegalArgumentException if there is illegal argument found.
+     * @throws InstantiationException if instantiation is provoked for the private constructor.
+     * @throws IllegalAccessException if instance is provoked or a method is provoked.
+     * @throws InvocationTargetException when an exception occurs by the method or constructor.
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException,
+    IllegalArgumentException, InstantiationException, IllegalAccessException, InvocationTargetException {
+        Class<?>[] classesToConstruct = {ClassDefinitionGenerator.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertNotNull(constructor.newInstance());
+        }
+    }
+
+    /**
+     * Unit test for builder class definition.
+     */
+    @Test
+    public void generateBuilderClassDefinitionTest() {
+
+        String builderClassDefinition = ClassDefinitionGenerator
+                .generateClassDefinition(GeneratedFileType.BUILDER_CLASS, "BuilderClass");
+        assertThat(true, is(builderClassDefinition.contains(UtilConstants.BUILDER)));
+        assertThat(true, is(builderClassDefinition.contains(UtilConstants.CLASS)));
+    }
+
+    /**
+     * Unit test for builder interface definition.
+     */
+    @Test
+    public void generateBuilderInterfaceDefinitionTest() {
+
+        String builderInterfaceDefinition = ClassDefinitionGenerator
+                .generateClassDefinition(GeneratedFileType.BUILDER_INTERFACE, "BuilderInterfaceClass");
+        assertThat(true, is(builderInterfaceDefinition.contains(UtilConstants.BUILDER)));
+    }
+
+    /**
+     * Unit test for impl class definition.
+     */
+    @Test
+    public void generateImplDefinitionTest() {
+
+        String implDefinition = ClassDefinitionGenerator.generateClassDefinition(GeneratedFileType.IMPL, "ImplClass");
+        assertThat(true, is(implDefinition.contains(UtilConstants.IMPL)));
+    }
+
+    /**
+     * Unit test for interface definition.
+     */
+    @Test
+    public void generateinterfaceDefinitionTest() {
+
+        String interfaceDefinition = ClassDefinitionGenerator.generateClassDefinition(GeneratedFileType.INTERFACE,
+                "InterfaceClass");
+        assertThat(true, is(interfaceDefinition.contains(UtilConstants.INTERFACE)));
+    }
+
+    /**
+     * Unit test for invalid generated type.
+     */
+    @Test
+    public void generateInvalidDefinitionTest() {
+
+        String invalidDefinition = ClassDefinitionGenerator.generateClassDefinition(GeneratedFileType.ALL, "invalid");
+        assertThat(true, is(invalidDefinition == null));
+    }
+
+    /**
+     * Unit test for enum data types.
+     */
+    @Test
+    public void enumDataTypesTest() {
+
+        TraversalType.valueOf(TraversalType.CHILD.toString());
+        GeneratedMethodTypes.valueOf(GeneratedMethodTypes.CONSTRUCTOR.toString());
+    }
+}