/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.hook;
import com.sun.jdi.VirtualMachine;
import java.io.File;
import java.io.IOException;
import java.util.StringTokenizer;
/**
* ProcessStarter uses JPDA JDI api to start a VM with a runtime modified java.lang.ClassLoader, or transparently use a
* Xbootclasspath style (java 1.3 detected or forced) <p/>
* <p/>
* <h2>Important note</h2>
* Due to a JPDA issue in LauchingConnector, this implementation is based on Process forking. If Xbootclasspath is not
* used the target VM is started with JDWP options <i>transport=dt_socket,address=9300 </i> unless other specified.
* <br/>It is possible after the short startup sequence to attach a debugger or any other JPDA attaching connector. It
* has been validated against a WebLogic 7 startup and is the <i>must use </i> implementation.
* </p>
* <p/>
* <p/>
* <h2>Implementation Note</h2>
* See http://java.sun.com/products/jpda/ <br/>See http://java.sun.com/j2se/1.4.1/docs/guide/jpda/jdi/index.html <br/>
* </p>
* <p/><p/>For java 1.3, it launch the target VM using a modified java.lang.ClassLoader by generating it and putting it
* in the bootstrap classpath of the target VM. The java 1.3 version should only be run for experimentation since it
* breaks the Java 2 Runtime Environment binary code license by overriding a class of rt.jar
* </p>
* <p/><p/>For java 1.4, it hotswaps java.lang.ClassLoader with a runtime patched version, wich is compatible with the
* Java 2 Runtime Environment binary code license. For JVM not supporting the class hotswapping, the same mechanism as
* for java 1.3 is used.
* </p>
* <p/>
* <p/>
* <h2>Usage</h2>
* Use it as a replacement of "java" :<br/><code>java [target jvm option] [target classpath]
* targetMainClass [targetMainClass args]</code>
* <br/>should be called like: <br/><code>java [jvm option] [classpath]
* org.codehaus.aspectwerkz.hook.ProcessStarter [target jvm option] [target classpath] targetMainClass [targetMainClass
* args]</code>
* <br/><b>[classpath] must contain %JAVA_HOME%/tools.jar for HotSwap support </b> <br/>[target jvm option] can contain
* JDWP options, transport and address are preserved if specified.
* </p>
* <p/>
* <p/>
* <h2>Options</h2>
* [classpath] must contain %JAVA_HOME%/tools.jar and the jar you want for bytecode modification (asm, bcel, ...)
* <br/>The java.lang.ClassLoader is patched using the <code>-Daspectwerkz.classloader.clpreprocessor=...</code> in
* [jvm option]. Specify the FQN of your implementation of hook.ClassLoaderPreProcessor. See {@link
* org.codehaus.aspectwerkz.hook.ClassLoaderPreProcessor} If not given, the default AspectWerkz layer 1 ASM
* implementation hook.impl.* is used, which is equivalent to
* <code>-Daspectwerkz.classloader.clpreprocessor=org.codehaus.aspectwerkz.hook.impl.ClassLoaderPreProcessorImpl</code>
* <br/>Use -Daspectwerkz.classloader.wait=2 in [jvm option] to force a pause of 2 seconds between process fork and JPDA
* connection for HotSwap. Defaults to no wait.
* </p>
* <p/>
* <p/>
* <h2>Disabling HotSwap</h2>
* You disable HotSwap and thus force the use of -Xbootclasspath (like in java 1.3 mode) and specify the directory where
* the modified class loader bytecode will be stored using in [jvm option]
* <code>-Daspectwerkz.classloader.clbootclasspath=...</code>. Specify the directory where you want the patched
* java.lang.ClassLoader to be stored. Default is "./_boot". The directory is created if needed (with the subdirectories
* corresponding to package names). <br/>The directory is <b>automatically </b> incorporated in the -Xbootclasspath
* option of [target jvm option]. <br/>You shoud use this option mainly for debuging purpose, or if you need to start
* different jvm with different classloader preprocessor implementations.
* </p>
* <p/>
* <p/>
* <h2>Option for AspectWerkz layer 1 ASM implementation</h2>
* When using the default AspectWerkz layer 1 ASM implementation
* <code>org.codehaus.aspectwerkz.hook.impl.ClassLoaderPreProcessorImpl</code>, java.lang.ClassLoader is modified to
* call a class preprocessor at each class load (except for class loaded by the bootstrap classloader). <br/>The
* effective class preprocessor is defined with <code>-Daspectwerkz.classloader.preprocessor=...</code> in [target jvm
* option]. Specify the FQN of your implementation of org.codehaus.aspectwerkz.hook.ClassPreProcessor interface. <br/>If
* this parameter is not given, the default AspectWerkz layer 2
* org.codehaus.aspectwerkz.transform.AspectWerkzPreProcessor is used. <br/>
* </p>
*
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur </a>
*/
public class ProcessStarter {
/**
* option for classloader preprocessor target
*/
final static String CL_PRE_PROCESSOR_CLASSNAME_PROPERTY = "aspectwerkz.classloader.clpreprocessor";
/**
* default dir when -Xbootclasspath is forced or used (java 1.3)
*/
private final static String CL_BOOTCLASSPATH_FORCE_DEFAULT = "." + File.separatorChar + "_boot";
/**
* option for target dir when -Xbootclasspath is forced or used (java 1.3)
*/
private final static String CL_BOOTCLASSPATH_FORCE_PROPERTY = "aspectwerkz.classloader.clbootclasspath";
/**
* option for seconds to wait before connecting
*/
private final static String CONNECTION_WAIT_PROPERTY = "aspectwerkz.classloader.wait";
/**
* target process
*/
private Process process = null;
/**
* used if target VM exits before launching VM
*/
private boolean executeShutdownHook = true;
/**
* thread to redirect streams of target VM in launching VM
*/
private Thread inThread;
/**
* thread to redirect streams of target VM in launching VM
*/
private Thread outThread;
/**
* thread to redirect streams of target VM in launching VM
*/
private Thread errThread;
/**
* Test if current java installation supports HotSwap
*/
private static boolean hasCanRedefineClass() {
try {
VirtualMachine.class.getMethod("canRedefineClasses", new Class[]{});
} catch (NoSuchMethodException e) {
return false;
}
return true;
}
private int run(String[] args) {
// retrieve options and main
String[] javaArgs = parseJavaCommandLine(args);
String optionArgs = javaArgs[0];
String cpArgs = javaArgs[1];
String mainArgs = javaArgs[2];
String options = optionArgs + " -cp " + cpArgs;
String clp = System.getProperty(
CL_PRE_PROCESSOR_CLASSNAME_PROPERTY,
"org.codehaus.aspectwerkz.hook.impl.ClassLoaderPreProcessorImpl"
);
// if java version does not support method "VirtualMachine.canRedefineClass"
// or if bootclasspath is forced, transform optionsArg
if (!hasCanRedefineClass() || (System.getProperty(CL_BOOTCLASSPATH_FORCE_PROPERTY) != null)) {
String bootDir = System.getProperty(CL_BOOTCLASSPATH_FORCE_PROPERTY, CL_BOOTCLASSPATH_FORCE_DEFAULT);
if (System.getProperty(CL_BOOTCLASSPATH_FORCE_PROPERTY) != null) {
System.out.println("HotSwap deactivated, using bootclasspath: " + bootDir);
} else {
System.out.println("HotSwap not supported by this java version, using bootclasspath: " + bootDir);
}
ClassLoaderPatcher.patchClassLoader(clp, bootDir);
BootClasspathStarter starter = new BootClasspathStarter(options, mainArgs, bootDir);
try {
process = starter.launchVM();
} catch (IOException e) {
System.err.println("failed to launch process :" + starter.getCommandLine());
e.printStackTrace();
return -1;
}
// attach stdout VM streams to this streams
// this is needed early to support -verbose:class like options
redirectStdoutStreams();
} else {
// lauch VM in suspend mode
JDWPStarter starter = new JDWPStarter(options, mainArgs, "dt_socket", "9300");
try {
process = starter.launchVM();
} catch (IOException e) {
System.err.println("failed to launch process :" + starter.getCommandLine());
e.printStackTrace();
return -1;
}
// attach stdout VM streams to this streams
// this is needed early to support -verbose:class like options
redirectStdoutStreams();
// override class loader in VM thru an attaching connector
int secondsToWait = 0;
try {
secondsToWait = Integer.parseInt(System.getProperty(CONNECTION_WAIT_PROPERTY, "0"));
} catch (NumberFormatException nfe) {
;
}
VirtualMachine vm = JDWPClassLoaderPatcher.hotswapClassLoader(
clp,
starter.getTransport(),
starter.getAddress(),
secondsToWait
);
if (vm == null) {
process.destroy();
} else {
vm.resume();
vm.dispose();
}
}
// attach VM other streams to this streams
redirectOtherStreams();
// add a shutdown hook to "this" to shutdown VM
Thread shutdownHook = new Thread() {
public void run() {
shutdown();
}
};
try {
Runtime.getRuntime().addShutdownHook(shutdownHook);
int exitCode = process.waitFor();
executeShutdownHook = false;
return exitCode;
} catch (Exception e) {
executeShutdownHook = false;
e.printStackTrace();
return -1;
}
}
/**
* shutdown target VM (used by shutdown hook of lauching VM)
*/
private void shutdown() {
if (executeShutdownHook) {
process.destroy();
}
try {
outThread.join();
errThread.join();
} catch (InterruptedException e) {
;
}
}
/**
* Set up stream redirection in target VM for stdout
*/
private void redirectStdoutStreams() {
outThread = new StreamRedirectThread("out.redirect", process.getInputStream(), System.out);
outThread.start();
}
/**
* Set up stream redirection in target VM for stderr and stdin
*/
private void redirectOtherStreams() {
inThread = new StreamRedirectThread("in.redirect", System.in, process.getOutputStream());
inThread.setDaemon(true);
errThread = new StreamRedirectThread("err.redirect", process.getErrorStream(), System.err);
inThread.start();
errThread.start();
}
public static void main(String[] args) {
System.exit((new ProcessStarter()).run(args));
}
private static String escapeWhiteSpace(String s) {
if (s.indexOf(' ') > 0) {
StringBuffer sb = new StringBuffer();
StringTokenizer st = new StringTokenizer(s, " ", true);
String current = null;
while (st.hasMoreTokens()) {
current = st.nextToken();
if (" ".equals(current)) {
sb.append("\\ ");
} else {
sb.append(current);
}
}
return sb.toString();
} else {
return s;
}
}
/**
* Remove first and last " or ' if any
*
* @param s string to handle
* @return s whitout first and last " or ' if any
*/
public static String removeEmbracingQuotes(String s) {
if ((s.length() >= 2) && (s.charAt(0) == '"') && (s.charAt(s.length() - 1) == '"')) {
return s.substring(1, s.length() - 1);
} else if ((s.length() >= 2) && (s.charAt(0) == '\'') && (s.charAt(s.length() - 1) == '\'')) {
return s.substring(1, s.length() - 1);
} else {
return s;
}
}
/**
* Analyse the args[] as a java command line
*
* @param args
* @return String[] [0]:jvm options except -cp|-classpath, [1]:classpath without -cp, [2]: mainClass + mainOptions
*/
public String[] parseJavaCommandLine(String[] args) {
StringBuffer optionsArgB = new StringBuffer();
StringBuffer cpOptionsArgB = new StringBuffer();
StringBuffer mainArgB = new StringBuffer();
String previous = null;
boolean foundMain = false;
for (int i = 0; i < args.length; i++) {
//System.out.println("" + i + " " + args[i]);
if (args[i].startsWith("-") && !foundMain) {
if (!("-cp".equals(args[i])) && !("-classpath").equals(args[i])) {
optionsArgB.append(args[i]).append(" ");
}
} else if (!foundMain && ("-cp".equals(previous) || "-classpath".equals(previous))) {
if (cpOptionsArgB.length() > 0) {
cpOptionsArgB.append(
(System.getProperty("os.name", "").toLowerCase().indexOf("windows") >= 0)
? ";"
: ":"
);
}
cpOptionsArgB.append(removeEmbracingQuotes(args[i]));
} else {
foundMain = true;
mainArgB.append(args[i]).append(" ");
}
previous = args[i];
}
// restore quote around classpath or escape whitespace depending on win*/*nix
StringBuffer classPath = new StringBuffer();
if (System.getProperty("os.name", "").toLowerCase().indexOf("windows") >= 0) {
classPath = classPath.append("\"").append(cpOptionsArgB.toString()).append("\"");
} else {
classPath = classPath.append(escapeWhiteSpace(cpOptionsArgB.toString()));
}
String[] res = new String[]{
optionsArgB.toString(), classPath.toString(), mainArgB.toString()
};
return res;
}
}