Commons Collections example source code file (TestCircularFifoBuffer.java)

This example Commons Collections source code file (TestCircularFifoBuffer.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

a, arraylist, b, b, bytearrayoutputstream, c, circularfifobuffer, circularfifobuffer, collection, d, exception, exception, io, object, object, util

The Commons Collections TestCircularFifoBuffer.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.buffer;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import junit.framework.Test;
import junit.textui.TestRunner;

import org.apache.commons.collections.Buffer;
import org.apache.commons.collections.BufferUnderflowException;
import org.apache.commons.collections.BulkTest;
import org.apache.commons.collections.collection.AbstractTestCollection;

/**
 * Test cases for CircularFifoBuffer.
 * 
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 * 
 * @author Stephen Colebourne
 */
public class TestCircularFifoBuffer extends AbstractTestCollection {

    public TestCircularFifoBuffer(String n) {
        super(n);
    }

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

    public static void main(String args[]) {
        TestRunner.run(TestCircularFifoBuffer.class);
    }

    //-----------------------------------------------------------------------
    /**
     *  Runs through the regular verifications, but also verifies that 
     *  the buffer contains the same elements in the same sequence as the
     *  list.
     */
    public void verify() {
        super.verify();
        Iterator iterator1 = collection.iterator();
        Iterator iterator2 = confirmed.iterator();
        while (iterator2.hasNext()) {
            assertTrue(iterator1.hasNext());
            Object o1 = iterator1.next();
            Object o2 = iterator2.next();
            assertEquals(o1, o2);
        }
    }

    //-----------------------------------------------------------------------
    /**
     * Overridden because UnboundedFifoBuffer doesn't allow null elements.
     * @return false
     */
    public boolean isNullSupported() {
        return false;
    }

    /**
     * Overridden because UnboundedFifoBuffer isn't fail fast.
     * @return false
     */
    public boolean isFailFastSupported() {
        return false;
    }

    //-----------------------------------------------------------------------
    /**
     * Returns an empty ArrayList.
     *
     * @return an empty ArrayList
     */
    public Collection makeConfirmedCollection() {
        return new ArrayList();
    }

    /**
     * Returns a full ArrayList.
     *
     * @return a full ArrayList
     */
    public Collection makeConfirmedFullCollection() {
        Collection c = makeConfirmedCollection();
        c.addAll(java.util.Arrays.asList(getFullElements()));
        return c;
    }

    /**
     * Returns an empty BoundedFifoBuffer that won't overflow.  
     *  
     * @return an empty BoundedFifoBuffer
     */
    public Collection makeCollection() {
        return new CircularFifoBuffer(100);
    }

    //-----------------------------------------------------------------------
    /**
     * Tests that the removal operation actually removes the first element.
     */
    public void testCircularFifoBufferCircular() {
        List list = new ArrayList();
        list.add("A");
        list.add("B");
        list.add("C");
        Buffer buf = new CircularFifoBuffer(list);
        
        assertEquals(true, buf.contains("A"));
        assertEquals(true, buf.contains("B"));
        assertEquals(true, buf.contains("C"));
        
        buf.add("D");
        
        assertEquals(false, buf.contains("A"));
        assertEquals(true, buf.contains("B"));
        assertEquals(true, buf.contains("C"));
        assertEquals(true, buf.contains("D"));
        
        assertEquals("B", buf.get());
        assertEquals("B", buf.remove());
        assertEquals("C", buf.remove());
        assertEquals("D", buf.remove());
    }

    /**
     * Tests that the removal operation actually removes the first element.
     */
    public void testCircularFifoBufferRemove() {
        resetFull();
        int size = confirmed.size();
        for (int i = 0; i < size; i++) {
            Object o1 = ((CircularFifoBuffer) collection).remove();
            Object o2 = ((ArrayList) confirmed).remove(0);
            assertEquals("Removed objects should be equal", o1, o2);
            verify();
        }

        try {
            ((CircularFifoBuffer) collection).remove();
            fail("Empty buffer should raise Underflow.");
        } catch (BufferUnderflowException e) {
            // expected
        }
    }

    /**
     * Tests that the constructor correctly throws an exception.
     */
    public void testConstructorException1() {
        try {
            new CircularFifoBuffer(0);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    /**
     * Tests that the constructor correctly throws an exception.
     */
    public void testConstructorException2() {
        try {
            new CircularFifoBuffer(-20);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }
    
    /**
     * Tests that the constructor correctly throws an exception.
     */
    public void testConstructorException3() {
        try {
            new CircularFifoBuffer(null);
        } catch (NullPointerException ex) {
            return;
        }
        fail();
    }
    
    public void testRemoveError1() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");
        
        assertEquals("[1, 2, 3, 4, 5]", fifo.toString());
        
        fifo.remove("3");
        assertEquals("[1, 2, 4, 5]", fifo.toString());
        
        fifo.remove("4");
        assertEquals("[1, 2, 5]", fifo.toString());
    }

    public void testRemoveError2() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");
        fifo.add("6");
        
        assertEquals(5, fifo.size());
        assertEquals("[2, 3, 4, 5, 6]", fifo.toString());
        
        fifo.remove("3");
        assertEquals("[2, 4, 5, 6]", fifo.toString());
        
        fifo.remove("4");
        assertEquals("[2, 5, 6]", fifo.toString());
    }

    public void testRemoveError3() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");
        
        assertEquals("[1, 2, 3, 4, 5]", fifo.toString());
        
        fifo.remove("3");
        assertEquals("[1, 2, 4, 5]", fifo.toString());
        
        fifo.add("6");
        fifo.add("7");
        assertEquals("[2, 4, 5, 6, 7]", fifo.toString());
        
        fifo.remove("4");
        assertEquals("[2, 5, 6, 7]", fifo.toString());
    }

    public void testRemoveError4() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        
        assertEquals("[3, 4, 5, 6, 7]", fifo.toString());
        
        fifo.remove("4");  // remove element in middle of array, after start
        assertEquals("[3, 5, 6, 7]", fifo.toString());
    }

    public void testRemoveError5() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        
        assertEquals("[3, 4, 5, 6, 7]", fifo.toString());
        
        fifo.remove("5");  // remove element at last pos in array
        assertEquals("[3, 4, 6, 7]", fifo.toString());
    }

    public void testRemoveError6() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        
        assertEquals("[3, 4, 5, 6, 7]", fifo.toString());
        
        fifo.remove("6");  // remove element at position zero in array
        assertEquals("[3, 4, 5, 7]", fifo.toString());
    }

    public void testRemoveError7() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        
        assertEquals("[3, 4, 5, 6, 7]", fifo.toString());
        
        fifo.remove("7");  // remove element at position one in array
        assertEquals("[3, 4, 5, 6]", fifo.toString());
    }

    public void testRemoveError8() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        fifo.add("8");  // end=3
        
        assertEquals("[4, 5, 6, 7, 8]", fifo.toString());
        
        fifo.remove("7");  // remove element at position one in array, need to shift 8
        assertEquals("[4, 5, 6, 8]", fifo.toString());
    }

    public void testRemoveError9() throws Exception {
        // based on bug 33071
        CircularFifoBuffer fifo = new CircularFifoBuffer(5);
        fifo.add("1");
        fifo.add("2");
        fifo.add("3");
        fifo.add("4");
        fifo.add("5");  // end=0
        fifo.add("6");  // end=1
        fifo.add("7");  // end=2
        fifo.add("8");  // end=3
        
        assertEquals("[4, 5, 6, 7, 8]", fifo.toString());
        
        fifo.remove("8");  // remove element at position two in array
        assertEquals("[4, 5, 6, 7]", fifo.toString());
    }

    //-----------------------------------------------------------------------
    public void testRepeatedSerialization() throws Exception {
        // bug 31433
        CircularFifoBuffer b = new CircularFifoBuffer(2);
        b.add("a");
        assertEquals(1, b.size());
        assertEquals(true, b.contains("a"));
        
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        new ObjectOutputStream(bos).writeObject(b);
        
        CircularFifoBuffer b2 = (CircularFifoBuffer) new ObjectInputStream(
            new ByteArrayInputStream(bos.toByteArray())).readObject();
        
        assertEquals(1, b2.size());
        assertEquals(true, b2.contains("a"));
        b2.add("b");
        assertEquals(2, b2.size());
        assertEquals(true, b2.contains("a"));
        assertEquals(true, b2.contains("b"));
        
        bos = new ByteArrayOutputStream();
        new ObjectOutputStream(bos).writeObject(b2);
        
        CircularFifoBuffer b3 = (CircularFifoBuffer) new ObjectInputStream(
            new ByteArrayInputStream(bos.toByteArray())).readObject();
        
        assertEquals(2, b3.size());
        assertEquals(true, b3.contains("a"));
        assertEquals(true, b3.contains("b"));
        b3.add("c");
        assertEquals(2, b3.size());
        assertEquals(true, b3.contains("b"));
        assertEquals(true, b3.contains("c"));
    }

    public String getCompatibilityVersion() {
        return "3.1";
    }

//    public void testCreate() throws Exception {
//        resetEmpty();
//        writeExternalFormToDisk((java.io.Serializable) collection, "D:/dev/collections/data/test/CircularFifoBuffer.emptyCollection.version3.1.obj");
//        resetFull();
//        writeExternalFormToDisk((java.io.Serializable) collection, "D:/dev/collections/data/test/CircularFifoBuffer.fullCollection.version3.1.obj");
//    }

}