Jira347Test.java
/*
* 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
*
* https://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.beanutils2.bugs;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertNotSame;
import static org.junit.jupiter.api.Assertions.assertSame;
import static org.junit.jupiter.api.Assertions.fail;
import java.beans.IntrospectionException;
import java.lang.ref.SoftReference;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Objects;
import org.apache.commons.beanutils2.MappedPropertyDescriptor;
import org.apache.commons.beanutils2.memoryleaktests.MemoryLeakTest;
import org.junit.jupiter.api.Test;
/**
* Test case for Jira issue# BEANUTILS-347.
*
* @see <a href="https://issues.apache.org/jira/browse/BEANUTILS-347">https://issues.apache.org/jira/browse/BEANUTILS-347</a>
*/
class Jira347Test {
/**
* Create a new class loader instance.
*/
private static URLClassLoader newClassLoader() throws MalformedURLException {
final String dataFilePath = MemoryLeakTest.class.getResource("pojotests").getFile();
// System.out.println("dataFilePath: " + dataFilePath);
final String location = "file://"
+ dataFilePath.substring(0, dataFilePath.length() - "org.apache.commons.beanutils2.memoryleaktests.pojotests".length());
// System.out.println("location: " + location);
final StringBuilder newString = new StringBuilder();
for (int i = 0; i < location.length(); i++) {
if (location.charAt(i) == '\\') {
newString.append("/");
} else {
newString.append(location.charAt(i));
}
}
final String classLocation = newString.toString();
// System.out.println("classlocation: " + classLocation);
final URLClassLoader theLoader = URLClassLoader.newInstance(new URL[] { new URL(classLocation) }, null);
return theLoader;
}
/**
* Try to force the garbage collector to run by filling up memory and calling System.gc().
*/
private void forceGarbageCollection() throws Exception {
// Fill up memory
final SoftReference<Object> ref = new SoftReference<>(new Object());
int count = 0;
while (ref.get() != null && count++ < 5) {
ArrayList<Object> list = new ArrayList<>();
try {
long i = 0;
while (ref.get() != null) {
list.add(
"A Big String A Big String A Big String A Big String A Big String A Big String A Big String A Big String A Big String A Big String "
+ i++);
}
} catch (final Throwable ignored) {
}
list.clear();
list = null;
// System.out.println("Count " + count + " : " + getMemoryStats());
System.gc();
Thread.sleep(1000);
}
// System.out.println("After GC: " + getMemoryStats());
if (ref.get() != null) {
throw new IllegalStateException("Your JVM is not releasing SoftReference, try running the test with less memory (-Xmx)");
}
}
/**
* Gets the string representation of the mapped write method for the given descriptor. This conversion is needed as there must not be strong reference
* to the Method object outside of this method as otherwise the garbage collector will not clean up the soft reference within the MappedPropertyDescriptor.
*
* @return the string representation or null if mapped write method does not exist
*/
private String getMappedWriteMethod(final MappedPropertyDescriptor descriptor) {
final Method m = descriptor.getMappedWriteMethod();
return Objects.toString(m, null);
}
/**
* Tests that MappedPropertyDescriptor does not throw an exception while re-creating a Method reference after it has been garbage collected under the
* following circumstances. - a class has a property 'mappedProperty' - there is no getter for this property - there is method
* setMappedProperty(MappedPropertyTestBean,MappedPropertyTestBean)
*
* In this case getMappedWriteMethod should not throw an exception after the method reference has been garbage collected. It is essential that in both cases
* the same method is returned or in both cases null. If the constructor of the MappedPropertyDescriptor would recognize the situation (of the first param
* not being of type String) this would be fine as well.
*/
@Test
void testMappedPropertyDescriptor_AnyArgsProperty() throws Exception {
final String className = "org.apache.commons.beanutils2.MappedPropertyTestBean";
try (final URLClassLoader loader = newClassLoader()) {
final Class<?> beanClass = loader.loadClass(className);
beanClass.newInstance();
// Sanity checks only
assertNotNull(loader, "ClassLoader is null");
assertNotNull(beanClass, "BeanClass is null");
assertNotSame(getClass().getClassLoader(), beanClass.getClassLoader(), "ClassLoaders should be different..");
assertSame(beanClass.getClassLoader(), loader, "BeanClass ClassLoader incorrect");
// now start the test
MappedPropertyDescriptor descriptor = null;
try {
descriptor = new MappedPropertyDescriptor("anyMapped", beanClass);
} catch (final IntrospectionException e) {
// this would be fine as well
}
if (descriptor != null) {
final String m1 = getMappedWriteMethod(descriptor);
forceGarbageCollection();
try {
final String m2 = getMappedWriteMethod(descriptor);
assertEquals(m1, m2, "Method returned post garbage collection differs from Method returned prior to gc");
} catch (final RuntimeException e) {
fail("getMappedWriteMethod threw an exception after garbage collection " + e);
}
}
}
}
}