/*
* 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.openjpa.enhance;
import java.lang.instrument.Instrumentation;
import java.security.AccessController;
import java.util.Iterator;
import java.util.List;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.conf.OpenJPAConfigurationImpl;
import org.apache.openjpa.lib.conf.Configuration;
import org.apache.openjpa.lib.conf.Configurations;
import org.apache.openjpa.lib.util.J2DoPrivHelper;
import org.apache.openjpa.lib.util.Options;
import org.apache.openjpa.util.ClassResolver;
/**
* <p>Java agent that makes persistent classes work with OpenJPA at runtime.
* This is achieved by either running the enhancer on the classes as they
* are loaded, or by redefining the classes on the fly.
* The agent is launched at JVM startup from the command line:</p>
*
* <p><code>java -javaagent:openjpa.jar[=<options>]</code>
* The options string should be formatted as a OpenJPA plugin, and may
* contain any properties understood by the OpenJPA enhancer or any
* configuration properties. For example:</p>
*
* <p><code>java -javaagent:openjpa.jar</code></p>
*
* <p>By default, if specified, the agent runs the OpenJPA enhancer on
* all classes listed in the first persistence unit as they are loaded,
* and redefines all other persistent classes when they are encountered.
* To disable enhancement at class-load time and rely solely on the
* redefinition logic, set the ClassLoadEnhancement flag to false. To
* disable redefinition and rely solely on pre-deployment or class-load
* enhancement, set the RuntimeRedefinition flag to false.
* </p>
*
* <p><code>java -javaagent:openjpa.jar=ClassLoadEnhancement=false</code></p>
*
* @author Abe White
* @author Patrick Linskey
*/
public class PCEnhancerAgent {
public static void premain(String args, Instrumentation inst) {
Options opts = Configurations.parseProperties(args);
if (opts.containsKey("ClassLoadEnhancement") ||
opts.containsKey("classLoadEnhancement")) {
if (opts.getBooleanProperty(
"ClassLoadEnhancement", "classLoadEnhancement", true))
registerClassLoadEnhancer(inst, opts);
}
else if (opts.containsKey("RuntimeEnhancement") ||
opts.containsKey("runtimeEnhancement")) {
// Deprecated property setting
if (opts.getBooleanProperty(
"RuntimeEnhancement", "runtimeEnhancement", true))
registerClassLoadEnhancer(inst, opts);
} else {
// if neither is set, then we should be turning it on. We need this
// logic instead of just a getBooleanProperty() because of the
// backwards-compat logic flow.
registerClassLoadEnhancer(inst, opts);
}
if (opts.getBooleanProperty(
"RuntimeRedefinition", "runtimeRedefinition", true)) {
InstrumentationFactory.setInstrumentation(inst);
} else {
InstrumentationFactory.setDynamicallyInstallAgent(false);
}
}
private static void registerClassLoadEnhancer(Instrumentation inst,
Options opts) {
List<String> anchors = Configurations.
getFullyQualifiedAnchorsInPropertiesLocation(opts);
for (String a : anchors) {
Options clonedOptions = (Options) opts.clone();
clonedOptions.setProperty("properties", a);
OpenJPAConfiguration conf = new OpenJPAConfigurationImpl();
Configurations.populateConfiguration(conf, clonedOptions);
// don't allow connections
conf.setConnectionUserName(null);
conf.setConnectionPassword(null);
conf.setConnectionURL(null);
conf.setConnectionDriverName(null);
conf.setConnectionFactoryName(null);
// set single class resolver
final ClassLoader tmpLoader = (ClassLoader) AccessController
.doPrivileged(J2DoPrivHelper
.newTemporaryClassLoaderAction((ClassLoader) AccessController
.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction())
));
conf.setClassResolver(new ClassResolver() {
public ClassLoader getClassLoader(Class context,
ClassLoader env) {
return tmpLoader;
}
});
conf.setReadOnly(Configuration.INIT_STATE_FREEZING);
conf.instantiateAll(); // avoid threading issues
PCClassFileTransformer transformer = new PCClassFileTransformer
(conf.newMetaDataRepositoryInstance(), clonedOptions,
tmpLoader);
inst.addTransformer(transformer);
conf.close();
}
}
}