Source for gnu.javax.rmi.CORBA.PortableRemoteObjectDelegateImpl

   1: /* PortableRemoteObjectDelegateImpl.java --
   2:    Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.javax.rmi.CORBA;
  40: 
  41: import gnu.CORBA.SimpleDelegate;
  42: import gnu.CORBA.Unexpected;
  43: import gnu.CORBA.Poa.LocalDelegate;
  44: import gnu.CORBA.Poa.ORB_1_4;
  45: import gnu.CORBA.Poa.AOM;
  46: 
  47: import java.rmi.NoSuchObjectException;
  48: import java.rmi.Remote;
  49: import java.rmi.RemoteException;
  50: import java.rmi.server.RMIClassLoader;
  51: 
  52: import javax.rmi.CORBA.PortableRemoteObjectDelegate;
  53: import javax.rmi.CORBA.Stub;
  54: import javax.rmi.CORBA.Tie;
  55: import javax.rmi.CORBA.Util;
  56: 
  57: import org.omg.CORBA.BAD_PARAM;
  58: import org.omg.CORBA.ORB;
  59: import org.omg.CORBA.portable.Delegate;
  60: import org.omg.CORBA.portable.ObjectImpl;
  61: import org.omg.PortableServer.POA;
  62: import org.omg.PortableServer.POAHelper;
  63: import org.omg.PortableServer.Servant;
  64: import org.omg.PortableServer.POAManagerPackage.State;
  65: 
  66: /**
  67:  * Implements PortableRemoteObjectDelegate.
  68:  *
  69:  * @author Wu Gansha (gansha.wu@intel.com) (stub)
  70:  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) (implementation)
  71:  */
  72: public class PortableRemoteObjectDelegateImpl
  73:   implements PortableRemoteObjectDelegate
  74: {
  75:   /**
  76:    * <p>
  77:    * Makes the remote object <code>a_target</code> ready for remote
  78:    * communication using the same communications runtime as for the passed
  79:    * <code>a_source</code> parameter. The a_target is connected to the same
  80:    * ORB (and, if applicable, to the same POA) as the a_source.
  81:    *
  82:    * @param a_target the target to connect to ORB, must be an instance of either
  83:    * {@link ObjectImpl} (Stubs and old-style ties) or {@link Servant} (POA-bases
  84:    * ties).
  85:    *
  86:    * @param a_source the object, providing the connection information, must be
  87:    * an instance of either {@link ObjectImpl} (Stubs and old-style ties) or
  88:    * {@link Servant} (POA-bases ties).
  89:    *
  90:    * @throws RemoteException if the target is already connected to another ORB.
  91:    */
  92:   public void connect(Remote a_target, Remote a_source)
  93:     throws RemoteException
  94:   {
  95:     ORB orb = null;
  96:     POA poa = null;
  97:     boolean ok = false;
  98: 
  99:     try
 100:       {
 101:         if (a_source instanceof Servant)
 102:           {
 103:             Servant s = (Servant) a_source;
 104:             orb = s._orb();
 105:             poa = s._poa();
 106:             ok = true;
 107:           }
 108: 
 109:         if (!ok && a_source instanceof ObjectImpl)
 110:           {
 111:             ObjectImpl o = (ObjectImpl) a_source;
 112:             orb = o._orb();
 113:             ok = true;
 114:             try
 115:               {
 116:                 if (orb instanceof ORB_1_4)
 117:                   {
 118:                     // POA information available.
 119:                     ORB_1_4 xorb = (ORB_1_4) orb;
 120:                     Delegate d = o._get_delegate();
 121: 
 122:                     if (d instanceof LocalDelegate)
 123:                       {
 124:                         LocalDelegate l = (LocalDelegate) d;
 125:                         poa = l.poa;
 126:                       }
 127:                     else if (d instanceof SimpleDelegate)
 128:                       {
 129:                         byte[] ior_key = ((SimpleDelegate) d).getIor().key;
 130:                         AOM.Obj ref = xorb.rootPOA.findIorKey(ior_key);
 131:                         if (ref != null)
 132:                           poa = ref.poa;
 133:                       }
 134:                   }
 135:               }
 136:             catch (Exception ex)
 137:               {
 138:                 // OK, POA info is not available, but as ORB is available, we
 139:                 // will connect in a default way.
 140:               }
 141:           }
 142:       }
 143:     catch (Exception ex)
 144:       {
 145:         RuntimeException rex = new RuntimeException("Unable to get info from "
 146:           + a_source);
 147:         rex.initCause(ex);
 148:         throw rex;
 149:       }
 150: 
 151:     if (!ok && a_source instanceof Tie)
 152:       {
 153:         Tie t = (Tie) a_source;
 154:         orb = t.orb();
 155:         poa = null;
 156:         ok = true;
 157:       }
 158: 
 159:     if (orb == null)
 160:       throw new RemoteException("Unable to determine ORB from " + a_source);
 161: 
 162:     if (a_target instanceof Stub)
 163:       {
 164:         StubDelegateImpl.connect((Stub) a_target, orb, poa);
 165:       }
 166:     else if (a_target instanceof Servant)
 167:       {
 168:         try
 169:           {
 170:             if (poa == null)
 171:               {
 172:                 poa = POAHelper.narrow(orb.resolve_initial_references("RootPOA"));
 173:                 // Activate if not active.
 174:                 if (poa.the_POAManager().get_state().value() == State._HOLDING)
 175:                   poa.the_POAManager().activate();
 176:               }
 177:             poa.servant_to_reference((Servant) a_target);
 178:           }
 179:         catch (Exception ex)
 180:           {
 181:             throw new Unexpected(ex);
 182:           }
 183:       }
 184:     else if (a_target instanceof org.omg.CORBA.Object)
 185:       {
 186:         // Connect as object.
 187:         orb.connect((org.omg.CORBA.Object) a_target);
 188:       }
 189:     else if (a_target instanceof Tie)
 190:       {
 191:         // We avoid calling this because it will aways connect to the root poa.
 192:         ((Tie) a_target).orb(orb);
 193:       }
 194:   }
 195: 
 196:   /**
 197:    * Narrow the given object to the instance of the given class. The currently
 198:    * supported narrowing types are:
 199:    *
 200:    * 1. Simple widening conversion.<br>
 201:    * 2. ObjectImpl -> RMI interface.<br>
 202:    * 3. ObjectImpl -> ObjectImpl.<br>
 203:    * 4. Tie -> Remote (implementation)<br>
 204:    * 5. Remote (implementation) -> Tie.<br>
 205:    *
 206:    * The narrowing has sense only for derived classes.
 207:    */
 208:   public Object narrow(Object narrowFrom, Class narrowTo)
 209:     throws ClassCastException
 210:   {
 211:     if (narrowTo == null)
 212:       throw new ClassCastException("Can't narrow to null class");
 213:     else if (narrowFrom == null)
 214:       return null;
 215:     else
 216:     // Simple narrowing case.
 217:     if (narrowTo.isAssignableFrom(narrowFrom.getClass()))
 218:       return narrowFrom;
 219:     else if (narrowTo.isInterface() || narrowFrom instanceof ObjectImpl)
 220:       {
 221:         // Narrow CORBA object to passed interface.
 222: 
 223:         String interf = narrowTo.getName();
 224:         String stubClassName;
 225: 
 226:         stubClassName = getStubClassName(interf);
 227: 
 228:         try
 229:           {
 230:             // Replace the interface class by the stub class.
 231:             narrowTo = Util.loadClass(stubClassName, null,
 232:               narrowTo.getClassLoader());
 233:           }
 234:         catch (ClassNotFoundException e)
 235:           {
 236:             ClassCastException cex = new ClassCastException("Class not found: "
 237:               + stubClassName);
 238:             cex.initCause(e);
 239:             throw cex;
 240:           }
 241:       }
 242:     else if (narrowFrom instanceof Tie)
 243:       {
 244:         // Try to substitute the return tie target as a return value.
 245:         Remote target = ((Tie) narrowFrom).getTarget();
 246:         if (target != null && narrowTo.isAssignableFrom(target.getClass()))
 247:           return target;
 248:       }
 249: 
 250:     Object narrowed;
 251:     try
 252:       {
 253:         narrowed = narrowTo.newInstance();
 254:       }
 255:     catch (Exception e)
 256:       {
 257:         ClassCastException cex = new ClassCastException("Cannot instantiate "
 258:           + narrowTo.getName());
 259:         cex.initCause(e);
 260:         throw cex;
 261:       }
 262: 
 263:     if (narrowed instanceof ObjectImpl)
 264:       {
 265:         // This also works for the instances of the Stub.
 266:         ObjectImpl target = (ObjectImpl) narrowed;
 267:         // Set the delegate, as is done in *Helper.narrow(..).
 268:         target._set_delegate(((ObjectImpl) narrowFrom)._get_delegate());
 269:       }
 270:     else if (narrowed instanceof Tie && narrowFrom instanceof Remote)
 271:       {
 272:         // Try to set the narrowing object as a target for the Tie.
 273:         ((Tie) narrowed).setTarget((Remote) narrowFrom);
 274:       }
 275:     else
 276:       throw new ClassCastException("Narrowing of " + narrowFrom.getClass()
 277:         + " to " + narrowTo + " is either not possible or not implemented.");
 278: 
 279:     return narrowed;
 280:   }
 281: 
 282:   /**
 283:    * Get the Stub class name for the name, representing the given interface.
 284:    */
 285:   static String getStubClassName(String interf)
 286:   {
 287:     String stubClassName;
 288:     int p = interf.lastIndexOf('.');
 289: 
 290:     if (p < 0)
 291:       // The interface is defined in the default package.
 292:       stubClassName = "_" + interf + "_Stub";
 293:     else
 294:       stubClassName = interf.substring(0, p + 1) + "_"
 295:         + interf.substring(p + 1) + "_Stub";
 296:     return stubClassName;
 297:   }
 298: 
 299:   /**
 300:    * Get stub for the given implementation, searching by class name pattern. The
 301:    * found stub must implement Remote for this method to succeed.
 302:    */
 303:   public Remote toStub(Remote ObjImpl)
 304:     throws NoSuchObjectException
 305:   {
 306:     String icn = ObjImpl.getClass().getName();
 307:     if (!icn.endsWith("Impl"))
 308:       throw new BAD_PARAM("Invalid class name '" + icn
 309:         + "', must end with 'Impl'");
 310: 
 311:     String sn = "_" + icn.substring(0, icn.length() - "Impl".length())
 312:       + "_Stub";
 313: 
 314:     Class stubClass;
 315:     Object o_stub;
 316: 
 317:     try
 318:       {
 319:         stubClass = RMIClassLoader.loadClass(sn);
 320:         o_stub = stubClass.newInstance();
 321:       }
 322:     catch (Exception e)
 323:       {
 324:         NoSuchObjectException n = new NoSuchObjectException(sn);
 325:         n.initCause(e);
 326:         throw n;
 327:       }
 328: 
 329:     if (!Remote.class.isAssignableFrom(stubClass))
 330:       throw new ClassCastException(stubClass.getName()
 331:         + " exists but cannot be returned as it does not inherit from "
 332:         + Remote.class.getName());
 333: 
 334:     return (Remote) o_stub;
 335:   }
 336: 
 337:   /**
 338:    * If the object tie is no longer in use, disconnet it from the orb.
 339:    */
 340:   public void unexportObject(Remote obj)
 341:     throws NoSuchObjectException
 342:   {
 343:     Util.unexportObject(obj);
 344:   }
 345: 
 346:   /**
 347:    * Find or create a tie for this target and mark it as being used by the given
 348:    * object.
 349:    */
 350:   public void exportObject(Remote obj)
 351:     throws RemoteException
 352:   {
 353:     if (obj instanceof Stub)
 354:       Util.registerTarget(StubDelegateImpl.getTieFromStub((Stub) obj), obj);
 355:     else if (obj instanceof Tie)
 356:       {
 357:         Tie t = (Tie) obj;
 358:         Util.registerTarget(t, null);
 359:       }
 360:   }
 361: 
 362: }