org.glowroot.container.impl.DelegatingJavaagent Maven / Gradle / Ivy
/*
* Copyright 2012-2015 the original author or authors.
*
* Licensed 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.glowroot.container.impl;
import java.io.File;
import java.io.FileOutputStream;
import java.lang.instrument.Instrumentation;
import java.lang.reflect.Method;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
import com.google.common.io.Resources;
import org.glowroot.common.ClassNames;
public class DelegatingJavaagent {
private static final String DELEGATE_JAVA_AGENT_PROPERTY = "delegateJavaagent";
private DelegatingJavaagent() {}
public static void premain(String agentArgs, Instrumentation instrumentation) throws Exception {
String delegateJavaagent = System.getProperty(DELEGATE_JAVA_AGENT_PROPERTY);
if (delegateJavaagent == null) {
throw new IllegalStateException("System property '" + DELEGATE_JAVA_AGENT_PROPERTY
+ "' is not set");
}
Class delegateClass = Class.forName(delegateJavaagent);
Method delegateMethod = delegateClass.getMethod("premain", String.class,
Instrumentation.class);
delegateMethod.invoke(null, agentArgs, instrumentation);
}
static File createDelegatingJavaagentJarFile(File dir) throws Exception {
File jarFile = File.createTempFile("glowroot-", ".jar", dir);
Manifest manifest = new Manifest();
manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
manifest.getMainAttributes().put(new Attributes.Name("Premain-Class"),
DelegatingJavaagent.class.getName());
manifest.getMainAttributes().put(new Attributes.Name("Can-Redefine-Classes"), "true");
manifest.getMainAttributes().put(new Attributes.Name("Can-Retransform-Classes"), "true");
JarOutputStream out = new JarOutputStream(new FileOutputStream(jarFile), manifest);
String resourceName =
ClassNames.toInternalName(DelegatingJavaagent.class.getName()) + ".class";
out.putNextEntry(new JarEntry(resourceName));
Resources.asByteSource(Resources.getResource(resourceName)).copyTo(out);
out.closeEntry();
out.close();
return jarFile;
}
}