beanificationtestcase.java

APACHE 公司出的java bean 工具包

/*
 * 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.beanutils;

import java.util.*;

import java.lang.ref.WeakReference;
import java.lang.ref.ReferenceQueue;

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

import org.apache.commons.logging.LogFactory;

/**
 * <p>
 * Test Case for changes made during Beanutils Beanification
 * </p>
 *
 * @author Robert Burrell Donkin
 * @author Juozas Baliuka
 * @version $Revision: 469737 $ $Date: 2006-11-01 01:16:55 +0000 (Wed, 01 Nov 2006) $
 */

public class BeanificationTestCase extends TestCase {
    
    // ---------------------------------------------------- Constants
    
    /** Maximum number of iterations before our test fails */
    public static final int MAX_GC_ITERATIONS = 50;
    
    // ---------------------------------------------------- Instance Variables


    // ---------------------------------------------------------- Constructors


    /**
     * Construct a new instance of this test case.
     *
     * @param name Name of the test case
     */
    public BeanificationTestCase(String name) {
        super(name);
    }


    // -------------------------------------------------- Overall Test Methods


    /**
     * Set up instance variables required by this test case.
     */
    public void setUp() {

        ConvertUtils.deregister();

    }


    /**
     * Return the tests included in this test suite.
     */
    public static Test suite() {
        return (new TestSuite(BeanificationTestCase.class));
    }


    /**
     * Tear down instance variables required by this test case.
     */
    public void tearDown() {
        // No action required
    }


    // ------------------------------------------------ Individual Test Methods
    
    /** Test of the methodology we'll use for some of the later tests */
    public void testMemoryTestMethodology() throws Exception {
        // test methodology
        // many thanks to Juozas Baliuka for suggesting this method
        ClassLoader loader = new ClassLoader(this.getClass().getClassLoader()) {};
        WeakReference reference = new  WeakReference(loader);
        Class myClass = loader.loadClass("org.apache.commons.beanutils.BetaBean");
        
        assertNotNull("Weak reference released early", reference.get());
        
        // dereference class loader and class:
        loader = null;
        myClass = null;
        
        int iterations = 0;
        int bytz = 2;
        while(true) {
            System.gc();
            if(iterations++ > MAX_GC_ITERATIONS){
                fail("Max iterations reached before resource released.");
            }
            if( reference.get() == null ) {
                break;
                
            } else {
                // create garbage:
                byte[] b =  new byte[bytz];
                bytz = bytz * 2;
            }
        }
    }
    
    /** Tests whether classloaders and beans are released from memory by the map used by beanutils */
    public void testMemoryLeak2() throws Exception {
        // tests when the map used by beanutils has the right behaviour
        
        if (isPre14JVM()) {
            System.out.println("WARNING: CANNOT TEST MEMORY LEAK ON PRE1.4 JVM");
            return;
        }
        
        // many thanks to Juozas Baliuka for suggesting this methodology
        TestClassLoader loader = new TestClassLoader();
        ReferenceQueue queue = new ReferenceQueue();
        WeakReference loaderReference = new WeakReference(loader, queue);
        Integer test = new Integer(1);
        
        WeakReference testReference = new WeakReference(test, queue);
        //Map map = new ReferenceMap(ReferenceMap.WEAK, ReferenceMap.HARD, true);
        Map map = new WeakHashMap();
        map.put(loader, test);
        
        assertEquals("In map", test, map.get(loader));
        assertNotNull("Weak reference released early (1)", loaderReference.get());
        assertNotNull("Weak reference released early (2)", testReference.get());
        
        // dereference strong references
        loader = null;
        test = null;
        
        int iterations = 0;
        int bytz = 2;
        while(true) {
            System.gc();
            if(iterations++ > MAX_GC_ITERATIONS){
                fail("Max iterations reached before resource released.");
            }
            map.isEmpty();
            
            if( 
                loaderReference.get() == null &&
                testReference.get() == null) {
                break;
                
            } else {
                // create garbage:
                byte[] b =  new byte[bytz];
                bytz = bytz * 2;
            }
        }
    }
    
    /** Tests whether classloaders and beans are released from memory */
    public void testMemoryLeak() throws Exception {
        if (isPre14JVM()) {
            System.out.println("WARNING: CANNOT TEST MEMORY LEAK ON PRE1.4 JVM");
            return;
        }
        
        // many thanks to Juozas Baliuka for suggesting this methodology
        TestClassLoader loader = new TestClassLoader();
        WeakReference loaderReference = new  WeakReference(loader);
        BeanUtilsBean.getInstance();

        class GetBeanUtilsBeanThread extends Thread {
            
            BeanUtilsBean beanUtils;
            ConvertUtilsBean convertUtils;
            PropertyUtilsBean propertyUtils;
        
            GetBeanUtilsBeanThread() {}
            
            public void run() {
                beanUtils = BeanUtilsBean.getInstance();
                convertUtils = ConvertUtilsBean.getInstance();
                propertyUtils = PropertyUtilsBean.getInstance();
                // XXX Log keeps a reference around!
                LogFactory.releaseAll();
            }
            
            public String toString() {
                return "GetBeanUtilsBeanThread";
            }
        }
        
    
        GetBeanUtilsBeanThread thread = new GetBeanUtilsBeanThread();
        WeakReference threadWeakReference = new WeakReference(thread);
        thread.setContextClassLoader(loader);

        thread.start();
        thread.join();
        
        WeakReference beanUtilsReference = new WeakReference(thread.beanUtils);
        WeakReference propertyUtilsReference =  new WeakReference(thread.propertyUtils);
        WeakReference convertUtilsReference = new WeakReference(thread.convertUtils);
        
        assertNotNull("Weak reference released early (1)", loaderReference.get());
        assertNotNull("Weak reference released early (2)", beanUtilsReference.get());
        assertNotNull("Weak reference released early (3)", propertyUtilsReference.get());
        assertNotNull("Weak reference released early (4)", convertUtilsReference.get());
        
        // dereference strong references
        loader = null;
        thread.setContextClassLoader(null);
        thread = null;
        
        int iterations = 0;
        int bytz = 2;
        while(true) {
            BeanUtilsBean.getInstance();
            System.gc();
            if(iterations++ > MAX_GC_ITERATIONS){
                fail("Max iterations reached before resource released.");
            }

            if( 
                loaderReference.get() == null &&
                beanUtilsReference.get() == null && 
                propertyUtilsReference.get() == null && 
                convertUtilsReference.get() == null) {
                break;
                
            } else {
                // create garbage:
                byte[] b =  new byte[bytz];
                bytz = bytz * 2;
            }
        }
    }
    
    /** 
     * Tests whether difference instances are loaded by different 
     * context classloaders.
     */
    public void testGetByContextClassLoader() throws Exception {
            
        class GetBeanUtilsBeanThread extends Thread {
            
            private Signal signal;
        
            GetBeanUtilsBeanThread(Signal signal) {
                this.signal = signal;
            }
            
            public void run() {
                signal.setSignal(2);