Commons Collections example source code file (TestSetUtils.java)

This example Commons Collections source code file (TestSetUtils.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

bulktest, collection, expecting, hashset, hashset, illegalargumentexception, illegalargumentexception, predicate, predicatedset, set, set, string, string, testsetutils, util

The Commons Collections TestSetUtils.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.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

import junit.framework.Test;

import org.apache.commons.collections.set.PredicatedSet;

/**
 * Tests for SetUtils.
 * 
 * @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 TestSetUtils extends BulkTest {

    public TestSetUtils(String name) {
        super(name);
    }

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

    public void testNothing() {
    }
    
    public void testpredicatedSet() {
        Predicate predicate = new Predicate() {
            public boolean evaluate(Object o) {
                return o instanceof String;
            }
        };
        Set set = SetUtils.predicatedSet(new HashSet(), predicate);
        assertTrue("returned object should be a PredicatedSet",
            set instanceof PredicatedSet);
        try {
            set = SetUtils.predicatedSet(new HashSet(), null);
            fail("Expecting IllegalArgumentException for null predicate.");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try {
            set = SetUtils.predicatedSet(null, predicate);
            fail("Expecting IllegalArgumentException for null set.");
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

    public void testEquals() {
        Collection data = Arrays.asList( new String[] { "a", "b", "c" });
        
        Set a = new HashSet( data );
        Set b = new HashSet( data );
        
        assertEquals(true, a.equals(b));
        assertEquals(true, SetUtils.isEqualSet(a, b));
        a.clear();
        assertEquals(false, SetUtils.isEqualSet(a, b));
        assertEquals(false, SetUtils.isEqualSet(a, null));
        assertEquals(false, SetUtils.isEqualSet(null, b));
        assertEquals(true, SetUtils.isEqualSet(null, null));
    }
    
    public void testHashCode() {
        Collection data = Arrays.asList( new String[] { "a", "b", "c" });
            
        Set a = new HashSet( data );
        Set b = new HashSet( data );
        
        assertEquals(true, a.hashCode() == b.hashCode());
        assertEquals(true, a.hashCode() == SetUtils.hashCodeForSet(a));
        assertEquals(true, b.hashCode() == SetUtils.hashCodeForSet(b));
        assertEquals(true, SetUtils.hashCodeForSet(a) == SetUtils.hashCodeForSet(b));
        a.clear();
        assertEquals(false, SetUtils.hashCodeForSet(a) == SetUtils.hashCodeForSet(b));
        assertEquals(0, SetUtils.hashCodeForSet(null));
    }   

}