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Commons Collections example source code file (AbstractTestSet.java)

This example Commons Collections source code file (AbstractTestSet.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

abstracttestcollection, abstracttestset, collection, collection, empty, empty, equal, full, hashset, iterator, set, set, sets, sets, util

The Commons Collections AbstractTestSet.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.set;

import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.apache.commons.collections.collection.AbstractTestCollection;

/**
 * Abstract test class for {@link Set} methods and contracts.
 * <p>
 * Since {@link Set} doesn't stipulate much new behavior that isn't already
 * found in {@link Collection}, this class basically just adds tests for
 * {@link Set#equals} and {@link Set#hashCode()} along with an updated
 * {@link #verify()} that ensures elements do not appear more than once in the
 * set.
 * <p>
 * To use, subclass and override the {@link #makeEmptySet()}
 * method.  You may have to override other protected methods if your
 * set is not modifiable, or if your set restricts what kinds of
 * elements may be added; see {@link AbstractTestCollection} for more details.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * 
 * @author Paul Jack
 */
public abstract class AbstractTestSet extends AbstractTestCollection {

    /**
     * JUnit constructor.
     *
     * @param name  name for test
     */
    public AbstractTestSet(String name) {
        super(name);
    }

    //-----------------------------------------------------------------------
    /**
     * Provides additional verifications for sets.
     */
    public void verify() {
        super.verify();
        
        assertEquals("Sets should be equal", confirmed, collection);
        assertEquals("Sets should have equal hashCodes", 
                     confirmed.hashCode(), collection.hashCode());
        Collection set = makeConfirmedCollection();
        Iterator iterator = collection.iterator();
        while (iterator.hasNext()) {
            assertTrue("Set.iterator should only return unique elements", 
                       set.add(iterator.next()));
        }
    }

    //-----------------------------------------------------------------------
    /**
     * Set equals method is defined.
     */
    public boolean isEqualsCheckable() {
        return true;
    }

    /**
     * Returns an empty Set for use in modification testing.
     *
     * @return a confirmed empty collection
     */
    public Collection makeConfirmedCollection() {
        return new HashSet();
    }

    /**
     * Returns a full Set for use in modification testing.
     *
     * @return a confirmed full collection
     */
    public Collection makeConfirmedFullCollection() {
        Collection set = makeConfirmedCollection();
        set.addAll(Arrays.asList(getFullElements()));
        return set;
    }

    /**
     * Makes an empty set.  The returned set should have no elements.
     *
     * @return an empty set
     */
    public abstract Set makeEmptySet();

    /**
     * Makes a full set by first creating an empty set and then adding
     * all the elements returned by {@link #getFullElements()}.
     *
     * Override if your set does not support the add operation.
     *
     * @return a full set
     */
    public Set makeFullSet() {
        Set set = makeEmptySet();
        set.addAll(Arrays.asList(getFullElements()));
        return set;
    }

    /**
     * Makes an empty collection by invoking {@link #makeEmptySet()}.  
     *
     * @return an empty collection
     */
    public final Collection makeCollection() {
        return makeEmptySet();
    }

    /**
     * Makes a full collection by invoking {@link #makeFullSet()}.
     *
     * @return a full collection
     */
    public final Collection makeFullCollection() {
        return makeFullSet();
    }

    //-----------------------------------------------------------------------
    /**
     * Return the {@link AbstractTestCollection#collection} fixture, but cast as a Set.  
     */
    public Set getSet() {
        return (Set)collection;
    }

    /**
     * Return the {@link AbstractTestCollection#confirmed} fixture, but cast as a Set.
     */
    public Set getConfirmedSet() {
        return (Set)confirmed;
    }

    //-----------------------------------------------------------------------
    /**
     * Tests {@link Set#equals(Object)}.
     */
    public void testSetEquals() {
        resetEmpty();
        assertEquals("Empty sets should be equal", 
                     getSet(), getConfirmedSet());
        verify();

        Collection set2 = makeConfirmedCollection();
        set2.add("foo");
        assertTrue("Empty set shouldn't equal nonempty set", 
                   !getSet().equals(set2));

        resetFull();
        assertEquals("Full sets should be equal", getSet(), getConfirmedSet());
        verify();

        set2.clear();
        set2.addAll(Arrays.asList(getOtherElements()));
        assertTrue("Sets with different contents shouldn't be equal", 
                   !getSet().equals(set2));
    }

    /**
     * Tests {@link Set#hashCode()}.
     */
    public void testSetHashCode() {
        resetEmpty();
        assertEquals("Empty sets have equal hashCodes", 
                     getSet().hashCode(), getConfirmedSet().hashCode());

        resetFull();
        assertEquals("Equal sets have equal hashCodes", 
                     getSet().hashCode(), getConfirmedSet().hashCode());
    }

}

Other Commons Collections examples (source code examples)

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