/**
* 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.cxf.common.logging;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLConnection;
import javax.imageio.ImageIO;
import javax.xml.parsers.DocumentBuilderFactory;
import org.apache.cxf.common.classloader.ClassLoaderUtils;
import org.apache.cxf.common.classloader.ClassLoaderUtils.ClassLoaderHolder;
/**
* This is called from LogUtils as LogUtils is almost always one of the VERY
* first classes loaded in CXF so we can try and register to hacks/workarounds
* for various bugs in the JDK.
*
* Much of this is taken from work the Tomcat folks have done to find
* places where memory leaks and jars are locked and such.
* See:
* http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/
* core/JreMemoryLeakPreventionListener.java
*
*/
final class JDKBugHacks {
private JDKBugHacks() {
//not constructed
}
public static void doHacks() {
try {
// Use the system classloader as the victim for all this
// ClassLoader pinning we're about to do.
ClassLoaderHolder orig = ClassLoaderUtils
.setThreadContextClassloader(ClassLoader.getSystemClassLoader());
try {
try {
//Trigger a call to sun.awt.AppContext.getAppContext()
ImageIO.getCacheDirectory();
} catch (Throwable t) {
//ignore
}
try {
// Several components end up opening JarURLConnections without first
// disabling caching. This effectively locks the file.
// JAXB does this and thus affects us pretty badly.
// Doesn't matter that this JAR doesn't exist - just as long as
// the URL is well-formed
URL url = new URL("jar:file://dummy.jar!/");
URLConnection uConn = new URLConnection(url) {
@Override
public void connect() throws IOException {
// NOOP
}
};
uConn.setDefaultUseCaches(false);
} catch (Throwable e) {
//ignore
}
try {
//DocumentBuilderFactory seems to SOMETIMES pin the classloader
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.newDocumentBuilder();
} catch (Throwable e) {
//ignore
}
// Several components end up calling:
// sun.misc.GC.requestLatency(long)
//
// Those libraries / components known to trigger memory leaks due to
// eventual calls to requestLatency(long) are:
// - javax.management.remote.rmi.RMIConnectorServer.start()
try {
Class<?> clazz = Class.forName("sun.misc.GC");
Method method = clazz.getDeclaredMethod("requestLatency",
new Class[] {Long.TYPE});
method.invoke(null, Long.valueOf(3600000));
} catch (Throwable e) {
//ignore
}
// Calling getPolicy retains a static reference to the context
// class loader.
try {
// Policy.getPolicy();
Class<?> policyClass = Class
.forName("javax.security.auth.Policy");
Method method = policyClass.getMethod("getPolicy");
method.invoke(null);
} catch (Throwable e) {
// ignore
}
try {
// Initializing javax.security.auth.login.Configuration retains a static reference
// to the context class loader.
Class.forName("javax.security.auth.login.Configuration", true,
ClassLoader.getSystemClassLoader());
} catch (Throwable e) {
// Ignore
}
// Creating a MessageDigest during web application startup
// initializes the Java Cryptography Architecture. Under certain
// conditions this starts a Token poller thread with TCCL equal
// to the web application class loader.
java.security.Security.getProviders();
} finally {
if (orig != null) {
orig.reset();
}
}
} catch (Throwable t) {
//ignore
}
}
}