Commons Collections example source code file (TestDefaultKeyValue.java)

This example Commons Collections source code file (TestDefaultKeyValue.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Collections tags/keywords

defaultkeyvalue, defaultkeyvalue, hashmap, illegalargumentexception, illegalargumentexception, map, map, object, should, string, string, test, testcase, testdefaultkeyvalue, util

The Commons Collections TestDefaultKeyValue.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.apache.commons.collections.keyvalue;

import java.util.HashMap;
import java.util.Map;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

/**
 * Test the DefaultKeyValue class.
 * 
 * @since Commons Collections 3.0
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * 
 * @author Neil O'Toole
 */
public class TestDefaultKeyValue extends TestCase {
    
    private final String key = "name";
    private final String value = "duke";

    /**
     * JUnit constructor.
     * 
     * @param testName  the test name
     */
    public TestDefaultKeyValue(String testName) {
        super(testName);

    }

    public static void main(String[] args) {
        junit.textui.TestRunner.run(TestDefaultKeyValue.class);
    }

    public static Test suite() {
        return new TestSuite(TestDefaultKeyValue.class);
    }

    //-----------------------------------------------------------------------
    /**
     * Make an instance of DefaultKeyValue with the default (null) key and value.
     * Subclasses should override this method to return a DefaultKeyValue
     * of the type being tested.
     */
    protected DefaultKeyValue makeDefaultKeyValue() {
        return new DefaultKeyValue(null, null);
    }

    /**
     * Make an instance of DefaultKeyValue with the specified key and value.
     * Subclasses should override this method to return a DefaultKeyValue
     * of the type being tested.
     */
    protected DefaultKeyValue makeDefaultKeyValue(Object key, Object value) {
        return new DefaultKeyValue(key, value);
    }

    //-----------------------------------------------------------------------
    public void testAccessorsAndMutators() {
        DefaultKeyValue kv = makeDefaultKeyValue();

        kv.setKey(key);
        assertTrue(kv.getKey() == key);

        kv.setValue(value);
        assertTrue(kv.getValue() == value);

        // check that null doesn't do anything funny
        kv.setKey(null);
        assertTrue(kv.getKey() == null);

        kv.setValue(null);
        assertTrue(kv.getValue() == null);

    }

    public void testSelfReferenceHandling() {
        // test that #setKey and #setValue do not permit
        //  the KVP to contain itself (and thus cause infinite recursion
        //  in #hashCode and #toString)

        DefaultKeyValue kv = makeDefaultKeyValue();

        try {
            kv.setKey(kv);
            fail("Should throw an IllegalArgumentException");
        } catch (IllegalArgumentException iae) {
            // expected to happen...

            // check that the KVP's state has not changed
            assertTrue(kv.getKey() == null && kv.getValue() == null);
        }

        try {
            kv.setValue(kv);
            fail("Should throw an IllegalArgumentException");
        } catch (IllegalArgumentException iae) {
            // expected to happen...

            // check that the KVP's state has not changed
            assertTrue(kv.getKey() == null && kv.getValue() == null);
        }
    }

    /**
     * Subclasses should override this method to test their own constructors.
     */
    public void testConstructors() {
        // 1. test default constructor
        DefaultKeyValue kv = new DefaultKeyValue();
        assertTrue(kv.getKey() == null && kv.getValue() == null);

        // 2. test key-value constructor
        kv = new DefaultKeyValue(key, value);
        assertTrue(kv.getKey() == key && kv.getValue() == value);

        // 3. test copy constructor
        DefaultKeyValue kv2 = new DefaultKeyValue(kv);
        assertTrue(kv2.getKey() == key && kv2.getValue() == value);

        // test that the KVPs are independent
        kv.setKey(null);
        kv.setValue(null);

        assertTrue(kv2.getKey() == key && kv2.getValue() == value);

        // 4. test Map.Entry constructor
        Map map = new HashMap();
        map.put(key, value);
        Map.Entry entry = (Map.Entry) map.entrySet().iterator().next();

        kv = new DefaultKeyValue(entry);
        assertTrue(kv.getKey() == key && kv.getValue() == value);

        // test that the KVP is independent of the Map.Entry
        entry.setValue(null);
        assertTrue(kv.getValue() == value);

    }

    public void testEqualsAndHashCode() {
        // 1. test with object data
        DefaultKeyValue kv = makeDefaultKeyValue(key, value);
        DefaultKeyValue kv2 = makeDefaultKeyValue(key, value);

        assertTrue(kv.equals(kv));
        assertTrue(kv.equals(kv2));
        assertTrue(kv.hashCode() == kv2.hashCode());

        // 2. test with nulls
        kv = makeDefaultKeyValue(null, null);
        kv2 = makeDefaultKeyValue(null, null);

        assertTrue(kv.equals(kv));
        assertTrue(kv.equals(kv2));
        assertTrue(kv.hashCode() == kv2.hashCode());
    }

    public void testToString() {
        DefaultKeyValue kv = makeDefaultKeyValue(key, value);
        assertTrue(kv.toString().equals(kv.getKey() + "=" + kv.getValue()));

        // test with nulls
        kv = makeDefaultKeyValue(null, null);
        assertTrue(kv.toString().equals(kv.getKey() + "=" + kv.getValue()));
    }

    public void testToMapEntry() {
        DefaultKeyValue kv = makeDefaultKeyValue(key, value);

        Map map = new HashMap();
        map.put(kv.getKey(), kv.getValue());
        Map.Entry entry = (Map.Entry) map.entrySet().iterator().next();

        assertTrue(entry.equals(kv.toMapEntry()));
        assertTrue(entry.hashCode() == kv.hashCode());
    }

}