libjava/gnu/java/rmi/server/UnicastServer.java

   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., 59 Temple Place, Suite 330, Boston, MA
  20 02111-1307 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.Hashtable;
  55
  56 public class UnicastServer
  57         implements ProtocolConstants {
  58
  59 static private Hashtable objects = new Hashtable();  //mapping OBJID to server ref
  60 static private Hashtable refcache = new Hashtable(); //mapping obj itself to server ref
  61 static private DGCImpl dgc;
  62
  63 public static void exportObject(UnicastServerRef obj) {
  64         startDGC();
  65         objects.put(obj.objid, obj);
  66         refcache.put(obj.myself, obj);
  67         obj.manager.startServer();
  68 }
  69
  70 // FIX ME: I haven't handle force parameter
  71 public static boolean unexportObject(UnicastServerRef obj, boolean force) {
  72         objects.remove(obj.objid);
  73         refcache.remove(obj.myself);
  74         obj.manager.stopServer();
  75         return true;
  76 }
  77
  78 public static UnicastServerRef getExportedRef(Remote remote){
  79     return (UnicastServerRef)refcache.get(remote);
  80 }
  81
  82 private static synchronized void startDGC() {
  83         if (dgc == null) {
  84                 try {
  85                         dgc = new DGCImpl();
  86                         // Changed DGCImpl to inherit UnicastServerRef directly
  87                         //((UnicastServerRef)dgc.getRef()).exportObject(dgc);
  88                         dgc.exportObject(dgc);
  89                 }
  90                 catch (RemoteException e) {
  91                         e.printStackTrace();
  92                 }
  93         }
  94 }
  95
  96 public static void dispatch(UnicastConnection conn) throws Exception {
  97         switch (conn.getDataInputStream().readUnsignedByte()) {
  98         case MESSAGE_CALL:
  99                 incomingMessageCall(conn);
 100                 break;
 101         case MESSAGE_PING:
 102                 // jdk sends a ping before each method call -> answer it!
 103                 DataOutputStream out = conn.getDataOutputStream();
 104                 out.writeByte(MESSAGE_PING_ACK);
 105                 out.flush();
 106                 break;
 107         default:
 108                 throw new Exception("bad method type");
 109         }
 110 }
 111
 112 private static void incomingMessageCall(UnicastConnection conn) throws IOException {
 113         ObjectInputStream in = conn.startObjectInputStream();  // (re)start ObjectInputStream
 114
 115         ObjID objid = ObjID.read(in);
 116         int method = in.readInt();
 117         long hash = in.readLong();
 118
 119 //System.out.println("ObjID: " + objid + ", method: " + method + ", hash: " + hash);
 120
 121         // Use the objid to locate the relevant UnicastServerRef
 122         UnicastServerRef uref = (UnicastServerRef)objects.get(objid);
 123         Object returnval;
 124         int returncode = RETURN_ACK;
 125         // returnval is from Method.invoke(), so we must check the return class to see
 126         // if it's primitive type
 127         Class returncls = null;
 128         if (uref != null) {
 129                 try {
 130                         // Dispatch the call to it.
 131                         returnval = uref.incomingMessageCall(conn, method, hash);
 132                         returncls = uref.getMethodReturnType(method, hash);
 133                 }
 134                 catch (Exception e) {
 135                         returnval = e;
 136                         returncode = RETURN_NACK;
 137                 }
 138                 catch (Error e) {
 139                         returnval = new ServerError ("An Error is thrown while processing the invocation on the server", e);
 140                         returncode = RETURN_NACK;
 141                 }
 142         }
 143         else {
 144                 returnval = new NoSuchObjectException("");
 145                 returncode = RETURN_NACK;
 146         }
 147
 148         conn.getDataOutputStream().writeByte(MESSAGE_CALL_ACK);
 149
 150         ObjectOutputStream out = conn.startObjectOutputStream();   // (re)start ObjectOutputStream
 151
 152         out.writeByte(returncode);
 153         (new UID()).write(out);
 154
 155         //System.out.println("returnval=" + returnval + " returncls=" + returncls);
 156
 157         if(returnval != null && returncls != null)
 158             ((RMIObjectOutputStream)out).writeValue(returnval, returncls);
 159
 160         // 1.1/1.2 void return type detection:
 161         else if (!(returnval instanceof RMIVoidValue || returncls == Void.TYPE))
 162             out.writeObject(returnval);
 163
 164         out.flush();
 165 }
 166
 167 }