com.alibaba.mtc.javassist.tools.rmi.AppletServer Maven / Gradle / Ivy
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a simple lib for transmitting context between thread even using thread pool.
/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist.tools.rmi;
import java.io.*;
import javassist.tools.web.*;
import javassist.CannotCompileException;
import javassist.NotFoundException;
import javassist.ClassPool;
import java.lang.reflect.Method;
import java.util.Hashtable;
import java.util.Vector;
/**
* An AppletServer object is a web server that an ObjectImporter
* communicates with. It makes the objects specified by
* exportObject() remotely accessible from applets.
* If the classes of the exported objects are requested by the client-side
* JVM, this web server sends proxy classes for the requested classes.
*
* @see javassist.tools.rmi.ObjectImporter
*/
public class AppletServer extends Webserver {
private StubGenerator stubGen;
private Hashtable exportedNames;
private Vector exportedObjects;
private static final byte[] okHeader
= "HTTP/1.0 200 OK\r\n\r\n".getBytes();
/**
* Constructs a web server.
*
* @param port port number
*/
public AppletServer(String port)
throws IOException, NotFoundException, CannotCompileException
{
this(Integer.parseInt(port));
}
/**
* Constructs a web server.
*
* @param port port number
*/
public AppletServer(int port)
throws IOException, NotFoundException, CannotCompileException
{
this(ClassPool.getDefault(), new StubGenerator(), port);
}
/**
* Constructs a web server.
*
* @param port port number
* @param src the source of classs files.
*/
public AppletServer(int port, ClassPool src)
throws IOException, NotFoundException, CannotCompileException
{
this(new ClassPool(src), new StubGenerator(), port);
}
private AppletServer(ClassPool loader, StubGenerator gen, int port)
throws IOException, NotFoundException, CannotCompileException
{
super(port);
exportedNames = new Hashtable();
exportedObjects = new Vector();
stubGen = gen;
addTranslator(loader, gen);
}
/**
* Begins the HTTP service.
*/
public void run() {
super.run();
}
/**
* Exports an object.
* This method produces the bytecode of the proxy class used
* to access the exported object. A remote applet can load
* the proxy class and call a method on the exported object.
*
* @param name the name used for looking the object up.
* @param obj the exported object.
* @return the object identifier
*
* @see javassist.tools.rmi.ObjectImporter#lookupObject(String)
*/
public synchronized int exportObject(String name, Object obj)
throws CannotCompileException
{
Class clazz = obj.getClass();
ExportedObject eo = new ExportedObject();
eo.object = obj;
eo.methods = clazz.getMethods();
exportedObjects.addElement(eo);
eo.identifier = exportedObjects.size() - 1;
if (name != null)
exportedNames.put(name, eo);
try {
stubGen.makeProxyClass(clazz);
}
catch (NotFoundException e) {
throw new CannotCompileException(e);
}
return eo.identifier;
}
/**
* Processes a request from a web browser (an ObjectImporter).
*/
public void doReply(InputStream in, OutputStream out, String cmd)
throws IOException, BadHttpRequest
{
if (cmd.startsWith("POST /rmi "))
processRMI(in, out);
else if (cmd.startsWith("POST /lookup "))
lookupName(cmd, in, out);
else
super.doReply(in, out, cmd);
}
private void processRMI(InputStream ins, OutputStream outs)
throws IOException
{
ObjectInputStream in = new ObjectInputStream(ins);
int objectId = in.readInt();
int methodId = in.readInt();
Exception err = null;
Object rvalue = null;
try {
ExportedObject eo
= (ExportedObject)exportedObjects.elementAt(objectId);
Object[] args = readParameters(in);
rvalue = convertRvalue(eo.methods[methodId].invoke(eo.object,
args));
}
catch(Exception e) {
err = e;
logging2(e.toString());
}
outs.write(okHeader);
ObjectOutputStream out = new ObjectOutputStream(outs);
if (err != null) {
out.writeBoolean(false);
out.writeUTF(err.toString());
}
else
try {
out.writeBoolean(true);
out.writeObject(rvalue);
}
catch (NotSerializableException e) {
logging2(e.toString());
}
catch (InvalidClassException e) {
logging2(e.toString());
}
out.flush();
out.close();
in.close();
}
private Object[] readParameters(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
int n = in.readInt();
Object[] args = new Object[n];
for (int i = 0; i < n; ++i) {
Object a = in.readObject();
if (a instanceof RemoteRef) {
RemoteRef ref = (RemoteRef)a;
ExportedObject eo
= (ExportedObject)exportedObjects.elementAt(ref.oid);
a = eo.object;
}
args[i] = a;
}
return args;
}
private Object convertRvalue(Object rvalue)
throws CannotCompileException
{
if (rvalue == null)
return null; // the return type is void.
String classname = rvalue.getClass().getName();
if (stubGen.isProxyClass(classname))
return new RemoteRef(exportObject(null, rvalue), classname);
else
return rvalue;
}
private void lookupName(String cmd, InputStream ins, OutputStream outs)
throws IOException
{
ObjectInputStream in = new ObjectInputStream(ins);
String name = DataInputStream.readUTF(in);
ExportedObject found = (ExportedObject)exportedNames.get(name);
outs.write(okHeader);
ObjectOutputStream out = new ObjectOutputStream(outs);
if (found == null) {
logging2(name + "not found.");
out.writeInt(-1); // error code
out.writeUTF("error");
}
else {
logging2(name);
out.writeInt(found.identifier);
out.writeUTF(found.object.getClass().getName());
}
out.flush();
out.close();
in.close();
}
}
class ExportedObject {
public int identifier;
public Object object;
public Method[] methods;
}