memoryleaktestcase.java

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/*
 * 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.memoryleaktests;

import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Locale;
import java.util.StringTokenizer;

import junit.framework.TestCase;

import org.apache.commons.beanutils.BeanUtilsBean;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.MappedPropertyDescriptor;
import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.beanutils.WrapDynaBean;
import org.apache.commons.beanutils.WrapDynaClass;
import org.apache.commons.beanutils.converters.IntegerConverter;
import org.apache.commons.beanutils.locale.LocaleBeanUtilsBean;
import org.apache.commons.beanutils.locale.LocaleConvertUtils;
import org.apache.commons.beanutils.locale.converters.IntegerLocaleConverter;

/**
 * Test BeanUtils memory leaks.
 * 
 * See https://issues.apache.org/jira/browse/BEANUTILS-291
 * 
 * @author Clebert Suconic
 */
public class MemoryLeakTestCase extends TestCase {

    /**
     * Tests that PropertyUtilsBean's descriptorsCache doesn't cause a memory leak.
     */
    public void testPropertyUtilsBean_descriptorsCache_memoryLeak() throws Exception {
        if (isPre15JVM()) {
            return;
        }

        // Clear All BeanUtils caches before the test
        clearAllBeanUtilsCaches();

        String className = "org.apache.commons.beanutils.memoryleaktests.pojotests.SomePojo";

        // The classLoader will go away only when these following variables are released
        ClassLoader loader = newClassLoader();
        Class beanClass    = loader.loadClass(className);
        Object bean        = beanClass.newInstance();
        // -----------------------------------------------------------------------------

        WeakReference someRef = new WeakReference(loader);

        // Sanity checks only
        assertNotNull("ClassLoader is null", loader);
        assertNotNull("BeanClass is null", beanClass);
        assertNotSame("ClassLoaders should be different..", getClass().getClassLoader(), beanClass.getClassLoader());
        assertSame("BeanClass ClassLoader incorrect", beanClass.getClassLoader(), loader);

        // if you comment the following line, the testcase will work, and the ClassLoader will be released.
        // That proves that nothing is wrong with the test, and PropertyUtils is holding a reference
        assertEquals("initialValue", PropertyUtils.getProperty(bean, "name"));

        // this should make the reference go away.
        loader    = null;
        beanClass = null;
        bean      = null;

        forceGarbageCollection(); /* Try to force the garbage collector to run by filling up memory */

        if (someRef.get() != null) {
            profilerLeakReport("PropertyUtilsBean descriptorsCache", className);
        }

        // if everything is fine, this will be null
        assertNull("PropertyUtilsBean is holding a reference to the classLoader", someRef.get());

        // Clear All BeanUtils caches after the test
        clearAllBeanUtilsCaches();
    }

    /**
     * Tests that PropertyUtilsBean's mappedDescriptorsCache doesn't cause a memory leak.
     */
    public void testPropertyUtilsBean_mappedDescriptorsCache_memoryLeak() throws Exception {
        if (isPre15JVM()) {
            return;
        }

        // Clear All BeanUtils caches before the test
        clearAllBeanUtilsCaches();

        String className = "org.apache.commons.beanutils.memoryleaktests.pojotests.SomeMappedPojo";

        // The classLoader will go away only when these following variables are released
        ClassLoader loader = newClassLoader();
        Class beanClass    = loader.loadClass(className);
        Object bean        = beanClass.newInstance();
        // -----------------------------------------------------------------------------

        WeakReference someRef = new WeakReference(loader);

        // Sanity checks only
        assertNotNull("ClassLoader is null", loader);
        assertNotNull("BeanClass is null", beanClass);
        assertNotSame("ClassLoaders should be different..", getClass().getClassLoader(), beanClass.getClassLoader());
        assertSame("BeanClass ClassLoader incorrect", beanClass.getClassLoader(), loader);

        // if you comment the following three lines, the testcase will work, and the ClassLoader will be released.
        // That proves that nothing is wrong with the test, and PropertyUtils is holding a reference
        assertEquals("Second Value", PropertyUtils.getProperty(bean, "mappedProperty(Second Key)"));
        PropertyUtils.setProperty(bean, "mappedProperty(Second Key)", "New Second Value");
        assertEquals("New Second Value", PropertyUtils.getProperty(bean, "mappedProperty(Second Key)"));

        // this should make the reference go away.
        loader = null;
        beanClass = null;
        bean = null;

        // PropertyUtilsBean uses the MethodUtils's method cache for mapped properties.
        // Uncomment the following line to check this is not just a repeat of that memory leak.
        // MethodUtils.clearCache();
        
        forceGarbageCollection(); /* Try to force the garbage collector to run by filling up memory */

        if (someRef.get() != null) {
            profilerLeakReport("PropertyUtilsBean mappedDescriptorsCache", className);
        }

        // if everything is fine, this will be null
        assertNull("PropertyUtilsBean is holding a reference to the classLoader", someRef.get());

        // Clear All BeanUtils caches after the test
        clearAllBeanUtilsCaches();
    }

    /**
     * Tests that MappedPropertyDescriptor can re-create the Method reference after it
     * has been garbage collected.
     */
    public void testMappedPropertyDescriptor_MappedMethodReference1() throws Exception {

        // Clear All BeanUtils caches before the test
        clearAllBeanUtilsCaches();

        String className = "org.apache.commons.beanutils.memoryleaktests.pojotests.SomeMappedPojo";
        ClassLoader loader = newClassLoader();
        Class beanClass    = loader.loadClass(className);
        Object bean        = beanClass.newInstance();
        // -----------------------------------------------------------------------------

        // Sanity checks only
        assertNotNull("ClassLoader is null", loader);
        assertNotNull("BeanClass is null", beanClass);
        assertNotSame("ClassLoaders should be different..", getClass().getClassLoader(), beanClass.getClassLoader());
        assertSame("BeanClass ClassLoader incorrect", beanClass.getClassLoader(), loader);

        MappedPropertyDescriptor descriptor = new MappedPropertyDescriptor("mappedProperty", beanClass);
        assertNotNull("1-Read Method null", descriptor.getMappedReadMethod());
        assertNotNull("1-Write Method null", descriptor.getMappedWriteMethod());
        assertEquals("1-Read Method name", "getMappedProperty", descriptor.getMappedReadMethod().getName());
        assertEquals("1-Read Write name", "setMappedProperty", descriptor.getMappedWriteMethod().getName());

        forceGarbageCollection(); /* Try to force the garbage collector to run by filling up memory */

        // The aim of this test is to check the functinality in MappedPropertyDescriptor which
        // re-creates the Method references after they have been garbage collected. However theres no
        // way of knowing the method references were garbage collected and that code was run, except by
        // un-commeting the System.out statement in MappedPropertyDescriptor's MappedMethodReference's
        // get() method.

        assertNotNull("1-Read Method null", descriptor.getMappedReadMethod());
        assertNotNull("1-Write Method null", descriptor.getMappedWriteMethod());
        assertEquals("1-Read Method name", "getMappedProperty", descriptor.getMappedReadMethod().getName());
        assertEquals("1-Read Write name", "setMappedProperty", descriptor.getMappedWriteMethod().getName());

        // Clear All BeanUtils caches after the test
        clearAllBeanUtilsCaches();
    }

    /**
     * Tests that MappedPropertyDescriptor can re-create the Method reference after it
     * has been garbage collected.
     */
    public void testMappedPropertyDescriptor_MappedMethodReference2() throws Exception {

        // Clear All BeanUtils caches before the test
        clearAllBeanUtilsCaches();

        String className = "org.apache.commons.beanutils.memoryleaktests.pojotests.SomeMappedPojo";
        ClassLoader loader = newClassLoader();
        Class beanClass    = loader.loadClass(className);
        Object bean        = beanClass.newInstance();
        // -----------------------------------------------------------------------------

        // Sanity checks only
        assertNotNull("ClassLoader is null", loader);
        assertNotNull("BeanClass is null", beanClass);
        assertNotSame("ClassLoaders should be different..", getClass().getClassLoader(), beanClass.getClassLoader());
        assertSame("BeanClass ClassLoader incorrect", beanClass.getClassLoader(), loader);

        MappedPropertyDescriptor descriptor = new MappedPropertyDescriptor("mappedProperty", beanClass);
        assertNotNull("1-Read Method null", descriptor.getMappedReadMethod());
        assertNotNull("1-Write Method null", descriptor.getMappedWriteMethod());
        assertEquals("1-Read Method name", "getMappedProperty", descriptor.getMappedReadMethod().getName());
        assertEquals("1-Read Write name", "setMappedProperty", descriptor.getMappedWriteMethod().getName());

        // this should make the reference go away.
        loader = null;
        beanClass = null;
        bean = null;

        forceGarbageCollection(); /* Try to force the garbage collector to run by filling up memory */

        // The aim of this test is to check the functinality in MappedPropertyDescriptor which
        // re-creates the Method references after they have been garbage collected. However theres no
        // way of knowing the method references were garbage collected and that code was run, except by
        // un-commeting the System.out statement in MappedPropertyDescriptor's MappedMethodReference's
        // get() method.

        assertNotNull("1-Read Method null", descriptor.getMappedReadMethod());
        assertNotNull("1-Write Method null", descriptor.getMappedWriteMethod());
        assertEquals("1-Read Method name", "getMappedProperty", descriptor.getMappedReadMethod().getName());
        assertEquals("1-Read Write name", "setMappedProperty", descriptor.getMappedWriteMethod().getName());

        // Clear All BeanUtils caches after the test
        clearAllBeanUtilsCaches();
    }

    /**
     * Tests that MethodUtils's cache doesn't cause a memory leak.
     */
    public void testMethodUtils_cache_memoryLeak() throws Exception {

        // Clear All BeanUtils caches before the test
        clearAllBeanUtilsCaches();

        String className = "org.apache.commons.beanutils.memoryleaktests.pojotests.SomePojo";

        // The classLoader will go away only when these following variables are released
        ClassLoader loader = newClassLoader();
        Class beanClass    = loader.loadClass(className);
        Object bean        = beanClass.newInstance();
        // -----------------------------------------------------------------------------

        WeakReference someRef = new WeakReference(loader);

        // Sanity checks only
        assertNotNull("ClassLoader is null", loader);
        assertNotNull("BeanClass is null", beanClass);
        assertNotSame("ClassLoaders should be different..", getClass().getClassLoader(), beanClass.getClassLoader());
        assertSame("BeanClass ClassLoader incorrect", beanClass.getClassLoader(), loader);

        // if you comment the following line, the testcase will work, and the ClassLoader will be released.
        // That proves that nothing is wrong with the test, and MethodUtils is holding a reference
        assertEquals("initialValue", MethodUtils.invokeExactMethod(bean, "getName", new Object[0]));

        // this should make the reference go away.
        loader    = null;
        beanClass = null;
        bean      = null;

        forceGarbageCollection(); /* Try to force the garbage collector to run by filling up memory */

        if (someRef.get() != null) {
            profilerLeakReport("MethodUtils cache", className);
        }

        // if everything is fine, this will be null
        assertNull("MethodUtils is holding a reference to the classLoader", someRef.get());