Commons Collections example source code file (TestListUtils.java)

This example Commons Collections source code file (TestListUtils.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, arraystack, collection, expecting, illegalargumentexception, illegalargumentexception, list, list, nullpointerexception, predicate, string, string, testlistutils, util

The Commons Collections TestListUtils.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;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

import junit.framework.Test;

import org.apache.commons.collections.list.PredicatedList;

/**
 * Tests for ListUtils.
 * 
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * 
 * @author Stephen Colebourne
 * @author Neil O'Toole
 * @author Matthew Hawthorne
 */
public class TestListUtils extends BulkTest {

    private static final String a = "a";
    private static final String b = "b";
    private static final String c = "c";
    private static final String d = "d";
    private static final String e = "e";
    private static final String x = "x";

    private String[] fullArray;
    private List fullList;
    
    public TestListUtils(String name) {
        super(name);
    }

    public static Test suite() {
        return BulkTest.makeSuite(TestListUtils.class);
    }

    public void setUp() {
        fullArray = new String[]{a, b, c, d, e};
        fullList = new ArrayList(Arrays.asList(fullArray));
    }
    
    
    public void testNothing() {
    }
    
    public void testpredicatedList() {
        Predicate predicate = new Predicate() {
            public boolean evaluate(Object o) {
                return o instanceof String;
            }
        };
        List list =
        ListUtils.predicatedList(new ArrayStack(), predicate);
        assertTrue("returned object should be a PredicatedList",
            list instanceof PredicatedList);
        try {
            list =
            ListUtils.predicatedList(new ArrayStack(), null);
            fail("Expecting IllegalArgumentException for null predicate.");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try {
            list =
            ListUtils.predicatedList(null, predicate);
            fail("Expecting IllegalArgumentException for null list.");
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

    public void testLazyList() {
        List list = ListUtils.lazyList(new ArrayList(), new Factory() {

            private int index;

            public Object create() {
                index++;
                return new Integer(index);
            }
        });

        assertNotNull((Integer)list.get(5));
        assertEquals(6, list.size());

        assertNotNull((Integer)list.get(5));
        assertEquals(6, list.size());
    }

    public void testEquals() {
        Collection data = Arrays.asList( new String[] { "a", "b", "c" });
        
        List a = new ArrayList( data );
        List b = new ArrayList( data );
        
        assertEquals(true, a.equals(b));
        assertEquals(true, ListUtils.isEqualList(a, b));
        a.clear();
        assertEquals(false, ListUtils.isEqualList(a, b));
        assertEquals(false, ListUtils.isEqualList(a, null));
        assertEquals(false, ListUtils.isEqualList(null, b));
        assertEquals(true, ListUtils.isEqualList(null, null));
    }
    
    public void testHashCode() {
        Collection data = Arrays.asList( new String[] { "a", "b", "c" });
            
        List a = new ArrayList( data );
        List b = new ArrayList( data );
        
        assertEquals(true, a.hashCode() == b.hashCode());
        assertEquals(true, a.hashCode() == ListUtils.hashCodeForList(a));
        assertEquals(true, b.hashCode() == ListUtils.hashCodeForList(b));
        assertEquals(true, ListUtils.hashCodeForList(a) == ListUtils.hashCodeForList(b));
        a.clear();
        assertEquals(false, ListUtils.hashCodeForList(a) == ListUtils.hashCodeForList(b));
        assertEquals(0, ListUtils.hashCodeForList(null));
    }
    
    public void testRetainAll() {
        List sub = new ArrayList();
        sub.add(a);
        sub.add(b);
        sub.add(x);

        List retained = ListUtils.retainAll(fullList, sub);
        assertTrue(retained.size() == 2);
        sub.remove(x);
        assertTrue(retained.equals(sub));
        fullList.retainAll(sub);
        assertTrue(retained.equals(fullList));
        
        try {
            List list = ListUtils.retainAll(null, null);
            fail("expecting NullPointerException");
        } catch(NullPointerException npe){} // this is what we want
    }

    public void testRemoveAll() {
        List sub = new ArrayList();
        sub.add(a);
        sub.add(b);
        sub.add(x);

        List remainder = ListUtils.removeAll(fullList, sub);
        assertTrue(remainder.size() == 3);
        fullList.removeAll(sub);
        assertTrue(remainder.equals(fullList));
        
        try {
            List list = ListUtils.removeAll(null, null);
            fail("expecting NullPointerException");
        } catch(NullPointerException npe) {} // this is what we want
    }
    
}