Commons Collections example source code file (TestListIteratorWrapper.java)

This example Commons Collections source code file (TestListIteratorWrapper.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

arraylist, arraylist, five, four, iteration, iteration, iterator, iterator, listiterator, object, object, six, testlistiteratorwrapper, two, util

The Commons Collections TestListIteratorWrapper.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.iterators;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;

import junit.framework.Test;
import junit.framework.TestSuite;
import org.apache.commons.collections.ResettableListIterator;

/**
 * Tests the ListIteratorWrapper to insure that it simulates
 * a ListIterator correctly.
 *
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * 
 * @author Morgan Delagrange
 */
public class TestListIteratorWrapper extends AbstractTestIterator {

    protected String[] testArray = {
        "One", "Two", "Three", "Four", "Five", "Six"
    };

    protected List list1 = null;

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

    public TestListIteratorWrapper(String testName) {
        super(testName);
    }

    public void setUp() {
        list1 = new ArrayList();
        list1.add("One");
        list1.add("Two");
        list1.add("Three");
        list1.add("Four");
        list1.add("Five");
        list1.add("Six");
    }

    public Iterator makeEmptyIterator() {
        ArrayList list = new ArrayList();
        return new ListIteratorWrapper(list.iterator());
    }

    public Iterator makeFullIterator() {
        Iterator i = list1.iterator();

        return new ListIteratorWrapper(i);
    }

    public void testIterator() {
        ListIterator iter = (ListIterator) makeFullIterator();
        for ( int i = 0; i < testArray.length; i++ ) {
            Object testValue = testArray[i];            
            Object iterValue = iter.next();

            assertEquals( "Iteration value is correct", testValue, iterValue );
        }

        assertTrue("Iterator should now be empty", ! iter.hasNext() );

        try {
            iter.next();
        } catch (Exception e) {
            assertTrue("NoSuchElementException must be thrown", 
                       e.getClass().equals((new NoSuchElementException()).getClass()));
        }

        // now, read it backwards
        for (int i = testArray.length - 1; i > -1; --i) {
            Object testValue = testArray[i];
            Object iterValue = iter.previous();

            assertEquals( "Iteration value is correct", testValue, iterValue );
        }

        try {
            iter.previous();
        } catch (Exception e) {
            assertTrue("NoSuchElementException must be thrown", 
                       e.getClass().equals((new NoSuchElementException()).getClass()));
        }

        // now, read it forwards again
        for ( int i = 0; i < testArray.length; i++ ) {
            Object testValue = testArray[i];            
            Object iterValue = iter.next();

            assertEquals( "Iteration value is correct", testValue, iterValue );
        }

    }

    public void testRemove() {
        Iterator iter = (Iterator) makeFullIterator();

        try {
            iter.remove();
            fail("FilterIterator does not support the remove() method");
        } catch (UnsupportedOperationException e) {

        }

    }

    public void testReset() {
        ResettableListIterator iter = (ResettableListIterator) makeFullIterator();
        Object first = iter.next();
        Object second = iter.next();
        
        iter.reset();
        
        // after reset, there shouldn't be any previous elements
        assertFalse("No previous elements after reset()", iter.hasPrevious());

        // after reset, the results should be the same as before
        assertEquals("First element should be the same", first, iter.next());
        assertEquals("Second elment should be the same", second, iter.next());
        
        // after passing the point, where we resetted, continuation should work as expected
        for (int i = 2; i < testArray.length; i++) {
            Object testValue = testArray[i];
            Object iterValue = iter.next();

            assertEquals("Iteration value is correct", testValue, iterValue);
        }
    }

}