Commons Collections example source code file (TestCollatingIterator.java)

This example Commons Collections source code file (TestCollatingIterator.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

abstracttestiterator, arraylist, arraylist, collatingiterator, collatingiterator, comparablecomparator, comparator, exception, integer, integer, iterator, test, testcollatingiterator, testcollatingiterator, util

The Commons Collections TestCollatingIterator.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.Comparator;
import java.util.Iterator;

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

import org.apache.commons.collections.comparators.ComparableComparator;

/**
 * Unit test suite for {@link CollatingIterator}.
 * 
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * @author Rodney Waldhoff
 */
public class TestCollatingIterator extends AbstractTestIterator {

    //------------------------------------------------------------ Conventional
    
    public TestCollatingIterator(String testName) {
        super(testName);
    }
    
    public static Test suite() {
        return new TestSuite(TestCollatingIterator.class);
    }

    //--------------------------------------------------------------- Lifecycle

    private Comparator comparator = null;
    private ArrayList evens = null; 
    private ArrayList odds = null; 
    private ArrayList fib = null; 

    public void setUp() throws Exception {
        super.setUp();
        comparator = new ComparableComparator();
        evens = new ArrayList();
        odds = new ArrayList();
        for(int i=0;i<20;i++) {
            if(0 == i%2) {
                evens.add(new Integer(i));
            } else {
                odds.add(new Integer(i));
            }
        }
        fib = new ArrayList();
        fib.add(new Integer(1));
        fib.add(new Integer(1));
        fib.add(new Integer(2));
        fib.add(new Integer(3));
        fib.add(new Integer(5));
        fib.add(new Integer(8));
        fib.add(new Integer(13));
        fib.add(new Integer(21));
    }       

    //---------------------------------------------------- TestIterator Methods
    
    public Iterator makeEmptyIterator() {
        return new CollatingIterator(comparator);
    }

    public Iterator makeFullIterator() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(evens.iterator());
        iter.addIterator(odds.iterator());
        iter.addIterator(fib.iterator());
        return iter;
    }

    //------------------------------------------------------------------- Tests

    public void testGetSetComparator() {
        CollatingIterator iter = new CollatingIterator();
        assertNull(iter.getComparator());
        iter.setComparator(comparator);
        assertSame(comparator,iter.getComparator());
        iter.setComparator(null);
        assertNull(iter.getComparator());
    }

    public void testIterateEven() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(evens.iterator());
        for(int i=0;i<evens.size();i++) {
            assertTrue(iter.hasNext());
            assertEquals(evens.get(i),iter.next());
        }
        assertTrue(!iter.hasNext());
    }

    public void testIterateEvenOdd() {
        CollatingIterator iter = new CollatingIterator(comparator,evens.iterator(),odds.iterator());
        for(int i=0;i<20;i++) {
            assertTrue(iter.hasNext());
            assertEquals(new Integer(i),iter.next());
        }
        assertTrue(!iter.hasNext());
    }

    public void testIterateOddEven() {
        CollatingIterator iter = new CollatingIterator(comparator,odds.iterator(),evens.iterator());
        for(int i=0;i<20;i++) {
            assertTrue(iter.hasNext());
            assertEquals(new Integer(i),iter.next());
        }
        assertTrue(!iter.hasNext());
    }

    public void testIterateEvenEven() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(evens.iterator());
        iter.addIterator(evens.iterator());
        for(int i=0;i<evens.size();i++) {
            assertTrue(iter.hasNext());
            assertEquals(evens.get(i),iter.next());
            assertTrue(iter.hasNext());
            assertEquals(evens.get(i),iter.next());
        }
        assertTrue(!iter.hasNext());
    }


    public void testIterateFibEvenOdd() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(fib.iterator());
        iter.addIterator(evens.iterator());
        iter.addIterator(odds.iterator());
        
        assertEquals(new Integer(0),iter.next());  // even   0
        assertEquals(new Integer(1),iter.next());  // fib    1
        assertEquals(new Integer(1),iter.next());  // fib    1
        assertEquals(new Integer(1),iter.next());  // odd    1
        assertEquals(new Integer(2),iter.next());  // fib    2
        assertEquals(new Integer(2),iter.next());  // even   2
        assertEquals(new Integer(3),iter.next());  // fib    3
        assertEquals(new Integer(3),iter.next());  // odd    3
        assertEquals(new Integer(4),iter.next());  // even   4
        assertEquals(new Integer(5),iter.next());  // fib    5
        assertEquals(new Integer(5),iter.next());  // odd    5
        assertEquals(new Integer(6),iter.next());  // even   6
        assertEquals(new Integer(7),iter.next());  // odd    7
        assertEquals(new Integer(8),iter.next());  // fib    8
        assertEquals(new Integer(8),iter.next());  // even   8
        assertEquals(new Integer(9),iter.next());  // odd    9
        assertEquals(new Integer(10),iter.next()); // even  10
        assertEquals(new Integer(11),iter.next()); // odd   11
        assertEquals(new Integer(12),iter.next()); // even  12
        assertEquals(new Integer(13),iter.next()); // fib   13
        assertEquals(new Integer(13),iter.next()); // odd   13
        assertEquals(new Integer(14),iter.next()); // even  14
        assertEquals(new Integer(15),iter.next()); // odd   15
        assertEquals(new Integer(16),iter.next()); // even  16
        assertEquals(new Integer(17),iter.next()); // odd   17
        assertEquals(new Integer(18),iter.next()); // even  18
        assertEquals(new Integer(19),iter.next()); // odd   19
        assertEquals(new Integer(21),iter.next()); // fib   21

        assertTrue(!iter.hasNext());
    }

    public void testRemoveFromSingle() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(evens.iterator());
        int expectedSize = evens.size();
        while(iter.hasNext()) {
            Integer val = (Integer)(iter.next());
            if(val.intValue() % 4 == 0) {
                expectedSize--;
                iter.remove();
            }
        }
        assertEquals(expectedSize,evens.size());
    }

    public void testRemoveFromDouble() {
        CollatingIterator iter = new CollatingIterator(comparator);
        iter.addIterator(evens.iterator());
        iter.addIterator(odds.iterator());
        int expectedSize = evens.size() + odds.size();
        while(iter.hasNext()) {
            Integer val = (Integer)(iter.next());
            if(val.intValue() % 4 == 0 || val.intValue() % 3 == 0 ) {
                expectedSize--;
                iter.remove();
            }
        }
        assertEquals(expectedSize,(evens.size() + odds.size()));
    }   

}