libjava/gnu/java/rmi/server/UnicastServerRef.java

/*
  Copyright (c) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
 
GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License.
 */

package gnu.java.rmi.server;

import java.net.ServerSocket;
import java.net.Socket;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.server.RemoteStub;
import java.rmi.server.ObjID;
import java.rmi.server.ServerRef;
import java.rmi.server.RemoteRef;
import java.rmi.server.ServerNotActiveException;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.server.RMIServerSocketFactory;
import java.rmi.server.UID;
import java.rmi.server.Skeleton;
import java.rmi.server.RemoteCall;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
import java.lang.Thread;
import java.lang.Exception;
import java.io.IOException;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Hashtable;

public class UnicastServerRef
	extends UnicastRef {

final static private Class[] stubprototype = new Class[] { RemoteRef.class };

Remote myself;
private Skeleton skel;
private RemoteStub stub;
private Hashtable methods;

public UnicastServerRef(ObjID id, int port, RMIServerSocketFactory ssf) {
	super(id);
	manager = UnicastConnectionManager.getInstance(port, ssf);
}

public RemoteStub exportObject(Remote obj) throws RemoteException {
	if (myself == null) {
		myself = obj;

		// Find and install the stub
		Class cls = obj.getClass();
		stub = (RemoteStub)getHelperClass(cls, "_Stub");
		if (stub == null) {
			throw new RemoteException("failed to export: " + cls);
		}

		// Find and install the skeleton (if there is one)
		skel = (Skeleton)getHelperClass(cls, "_Skel");

		// Build hash of methods which may be called.
		buildMethodHash(obj.getClass());

		// Export it.
		UnicastServer.exportObject(this);
	}

	return (stub);
}

private Object getHelperClass(Class cls, String type) {
	try {   
		String classname = cls.getName();
		Class scls = Class.forName(classname + type);
		if (type.equals("_Stub")) {
			try {
				// JDK 1.2 stubs
				Constructor con = scls.getConstructor(stubprototype);
				return (con.newInstance(new Object[]{this}));
			}
			catch (NoSuchMethodException e) {
			}
			catch (InstantiationException e) {
			}
			catch (IllegalAccessException e) {
			}
			catch (IllegalArgumentException e) {
			}
			catch (InvocationTargetException e) {
			}
			// JDK 1.1 stubs
			RemoteStub stub = (RemoteStub)scls.newInstance();
			UnicastRemoteStub.setStubRef(stub, this);
			return (stub);
		}
		else {
			// JDK 1.1 skel
			return (scls.newInstance());
		}
	}
	catch (ClassNotFoundException e) {
	}
	catch (InstantiationException e) {
	}
	catch (IllegalAccessException e) {
	}
	return (null);
}

public String getClientHost() throws ServerNotActiveException {
	throw new Error("Not implemented");
}

private void buildMethodHash(Class cls) {
	methods = new Hashtable();
	Method[] meths = cls.getMethods();
	for (int i = 0; i < meths.length; i++) {
		/* Don't need to include any java.xxx related stuff */
		if (meths[i].getDeclaringClass().getName().startsWith("java.")) {
			continue;
		}
		long hash = RMIHashes.getMethodHash(meths[i]);
		methods.put(new Long (hash), meths[i]);
//System.out.println("meth = " + meths[i] + ", hash = " + hash);
	}
}

public Object incomingMessageCall(UnicastConnection conn, int method, long hash) throws Exception {
//System.out.println("method = " + method + ", hash = " + hash);
	// If method is -1 then this is JDK 1.2 RMI - so use the hash
	// to locate the method
	if (method == -1) {
		Method meth = (Method)methods.get(new Long (hash));
//System.out.println("class = " + myself.getClass() + ", meth = " + meth);
		if (meth == null) {
			throw new NoSuchMethodException();
		}

		ObjectInputStream in = conn.getObjectInputStream();
		int nrargs = meth.getParameterTypes().length;
		Object[] args = new Object[nrargs];
		for (int i = 0; i < nrargs; i++) {
			/** 
			 * For debugging purposes - we don't handle CodeBases
			 * quite right so we don't always find the stubs.  This
			 * lets us know that.
			 */
			try {
				args[i] = in.readObject();
			}
			catch (Exception t) {
				t.printStackTrace();
				throw t;
			}
		}
		return (meth.invoke(myself, args));
	}
	// Otherwise this is JDK 1.1 style RMI - we find the skeleton
	// and invoke it using the method number.  We wrap up our
	// connection system in a UnicastRemoteCall so it appears in a
	// way the Skeleton can handle.
	else {
		if (skel == null) {
			throw new NoSuchMethodException();
		}
		UnicastRemoteCall call = new UnicastRemoteCall(conn);
		skel.dispatch(myself, call, method, hash);
		return (call.returnValue());
	}
}

}