Commons Collections example source code file (TestArrayListIterator.java)

This example Commons Collections source code file (TestArrayListIterator.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

arraylistiterator, arraylistiterator, illegalstateexception, iteration, iterator, listiterator, listiterator, nosuchelementexception, object, object, string, string, testarraylistiterator, the, util

The Commons Collections TestArrayListIterator.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.Arrays;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.NoSuchElementException;

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

/**
 * Test the ArrayListIterator class.
 * 
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * @author Neil O'Toole
 */
public class TestArrayListIterator extends TestArrayIterator {

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

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

    public Iterator makeEmptyIterator() {
        return new ArrayListIterator(new Object[0]);
    }

    public Iterator makeFullIterator() {
        return new ArrayListIterator(testArray);
    }

    public ListIterator makeArrayListIterator(Object array) {
        return new ArrayListIterator(array);
    }

    public boolean supportsRemove() {
        return false;
    }

    /**
     * Test the basic ListIterator functionality - going backwards using
     * <code>previous().
     */
    public void testListIterator() {
        ListIterator iter = (ListIterator) makeFullIterator();

        // TestArrayIterator#testIterator() has already tested the iterator forward,
        //  now we need to test it in reverse

        // fast-forward the iterator to the end...
        while (iter.hasNext()) {
            iter.next();
        }

        for (int x = testArray.length - 1; x >= 0; x--) {
            Object testValue = testArray[x];
            Object iterValue = iter.previous();

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

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

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

    }

    /**
     * Tests the {@link java.util.ListIterator#set} operation.
     */
    public void testListIteratorSet() {
        String[] testData = new String[] { "a", "b", "c" };

        String[] result = new String[] { "0", "1", "2" };

        ListIterator iter = (ListIterator) makeArrayListIterator(testData);
        int x = 0;

        while (iter.hasNext()) {
            iter.next();
            iter.set(Integer.toString(x));
            x++;
        }

        assertTrue("The two arrays should have the same value, i.e. {0,1,2}", Arrays.equals(testData, result));

        // a call to set() before a call to next() or previous() should throw an IllegalStateException
        iter = makeArrayListIterator(testArray);

        try {
            iter.set("should fail");
            fail("ListIterator#set should fail if next() or previous() have not yet been called.");
        } catch (IllegalStateException e) {
            // expected
        } catch (Throwable t) { // should never happen
            fail(t.toString());
        }

    }

}