Source for gnu.java.rmi.server.UnicastServer

   1: /* UnicastServer.java --
   2:    Copyright (c) 1996, 1997, 1998, 1999, 2002, 2004
   3:    Free Software Foundation, Inc.
   4: 
   5: This file is part of GNU Classpath.
   6: 
   7: GNU Classpath is free software; you can redistribute it and/or modify
   8: it under the terms of the GNU General Public License as published by
   9: the Free Software Foundation; either version 2, or (at your option)
  10: any later version.
  11:  
  12: GNU Classpath is distributed in the hope that it will be useful, but
  13: WITHOUT ANY WARRANTY; without even the implied warranty of
  14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15: General Public License for more details.
  16: 
  17: You should have received a copy of the GNU General Public License
  18: along with GNU Classpath; see the file COPYING.  If not, write to the
  19: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20: 02110-1301 USA.
  21: 
  22: Linking this library statically or dynamically with other modules is
  23: making a combined work based on this library.  Thus, the terms and
  24: conditions of the GNU General Public License cover the whole
  25: combination.
  26: 
  27: As a special exception, the copyright holders of this library give you
  28: permission to link this library with independent modules to produce an
  29: executable, regardless of the license terms of these independent
  30: modules, and to copy and distribute the resulting executable under
  31: terms of your choice, provided that you also meet, for each linked
  32: independent module, the terms and conditions of the license of that
  33: module.  An independent module is a module which is not derived from
  34: or based on this library.  If you modify this library, you may extend
  35: this exception to your version of the library, but you are not
  36: obligated to do so.  If you do not wish to do so, delete this
  37: exception statement from your version. */
  38: 
  39: 
  40: package gnu.java.rmi.server;
  41: 
  42: import gnu.java.rmi.dgc.DGCImpl;
  43: 
  44: import java.io.DataOutputStream;
  45: import java.io.IOException;
  46: import java.io.ObjectInputStream;
  47: import java.io.ObjectOutputStream;
  48: import java.rmi.NoSuchObjectException;
  49: import java.rmi.Remote;
  50: import java.rmi.RemoteException;
  51: import java.rmi.ServerError;
  52: import java.rmi.server.ObjID;
  53: import java.rmi.server.UID;
  54: import java.util.Collections;
  55: import java.util.Map;
  56: import java.util.Hashtable;
  57: import java.util.IdentityHashMap;
  58: 
  59: public class UnicastServer
  60:     implements ProtocolConstants {
  61: 
  62: static private Hashtable objects = new Hashtable();  //mapping OBJID to server ref
  63: static private Map refcache = Collections.synchronizedMap(new IdentityHashMap()); //mapping obj itself to server ref
  64: static private DGCImpl dgc;
  65: 
  66: public static void exportObject(UnicastServerRef obj) {
  67:     startDGC();
  68:     objects.put(obj.objid, obj);
  69:     refcache.put(obj.myself, obj);
  70:     obj.manager.startServer();
  71: }
  72: 
  73: // FIX ME: I haven't handle force parameter
  74: public static boolean unexportObject(UnicastServerRef obj, boolean force) {
  75:     objects.remove(obj.objid);
  76:     refcache.remove(obj.myself);
  77:     obj.manager.stopServer();
  78:     return true;
  79: }
  80: 
  81: public static UnicastServerRef getExportedRef(Remote remote){
  82:     return (UnicastServerRef)refcache.get(remote);
  83: }
  84: 
  85: private static synchronized void startDGC() {
  86:     if (dgc == null) {
  87:         try {
  88:             dgc = new DGCImpl();
  89:             // Changed DGCImpl to inherit UnicastServerRef directly
  90:             //((UnicastServerRef)dgc.getRef()).exportObject(dgc);
  91:             dgc.exportObject(dgc);
  92:         }
  93:         catch (RemoteException e) {
  94:             e.printStackTrace();
  95:         }
  96:     }
  97: }
  98: 
  99: public static void dispatch(UnicastConnection conn) throws Exception {
 100:     switch (conn.getDataInputStream().readUnsignedByte()) {
 101:     case MESSAGE_CALL:
 102:         incomingMessageCall(conn);
 103:         break;
 104:     case MESSAGE_PING:  
 105:         // jdk sends a ping before each method call -> answer it!
 106:         DataOutputStream out = conn.getDataOutputStream();
 107:         out.writeByte(MESSAGE_PING_ACK);
 108:         out.flush();
 109:         break;
 110:     default:
 111:         throw new Exception("bad method type");
 112:     }
 113: }
 114: 
 115: private static void incomingMessageCall(UnicastConnection conn) throws IOException {
 116:     ObjectInputStream in = conn.startObjectInputStream();  // (re)start ObjectInputStream
 117: 
 118:     ObjID objid = ObjID.read(in);
 119:     int method = in.readInt();
 120:     long hash = in.readLong();
 121: 
 122: //System.out.println("ObjID: " + objid + ", method: " + method + ", hash: " + hash);
 123: 
 124:     // Use the objid to locate the relevant UnicastServerRef
 125:     UnicastServerRef uref = (UnicastServerRef)objects.get(objid);
 126:     Object returnval;
 127:     int returncode = RETURN_ACK;
 128:     // returnval is from Method.invoke(), so we must check the return class to see
 129:     // if it's primitive type
 130:     Class returncls = null;
 131:     if (uref != null) {
 132:         try {
 133:             // Dispatch the call to it.
 134:             returnval = uref.incomingMessageCall(conn, method, hash);
 135:             returncls = uref.getMethodReturnType(method, hash);
 136:         }
 137:         catch (Exception e) {
 138:             returnval = e;
 139:             returncode = RETURN_NACK;
 140:         }
 141:                 catch (Error e) {
 142:             returnval = new ServerError ("An Error is thrown while processing the invocation on the server", e);
 143:             returncode = RETURN_NACK;
 144:                 }
 145:     }
 146:     else {
 147:         returnval = new NoSuchObjectException("");
 148:         returncode = RETURN_NACK;
 149:     }
 150: 
 151:     conn.getDataOutputStream().writeByte(MESSAGE_CALL_ACK);
 152: 
 153:     ObjectOutputStream out = conn.startObjectOutputStream();   // (re)start ObjectOutputStream
 154: 
 155:     out.writeByte(returncode);
 156:     (new UID()).write(out);
 157: 
 158:     //System.out.println("returnval=" + returnval + " returncls=" + returncls);
 159: 
 160:     if(returnval != null && returncls != null)
 161:         ((RMIObjectOutputStream)out).writeValue(returnval, returncls);
 162: 
 163:     // 1.1/1.2 void return type detection:
 164:     else if (!(returnval instanceof RMIVoidValue || returncls == Void.TYPE)) 
 165:         out.writeObject(returnval);
 166: 
 167:     out.flush();
 168: }
 169: 
 170: }