mirror of git://gcc.gnu.org/git/gcc.git
230 lines
8.0 KiB
Java
230 lines
8.0 KiB
Java
/* RemoteObjectInvocationHandler.java -- RMI stub replacement.
|
|
Copyright (C) 2005 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., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.rmi.server;
|
|
|
|
import gnu.java.rmi.server.RMIHashes;
|
|
|
|
import java.io.Serializable;
|
|
import java.lang.reflect.InvocationHandler;
|
|
import java.lang.reflect.Method;
|
|
import java.lang.reflect.Proxy;
|
|
import java.rmi.Remote;
|
|
import java.rmi.RemoteException;
|
|
import java.rmi.UnexpectedException;
|
|
import java.rmi.registry.Registry;
|
|
import java.rmi.server.RemoteObject;
|
|
import java.rmi.server.RemoteRef;
|
|
import java.rmi.server.UnicastRemoteObject;
|
|
import java.util.Hashtable;
|
|
|
|
/**
|
|
* Together with dynamic proxy instance, this class replaces the generated RMI
|
|
* stub (*_Stub) classes that (following 1.5 specification) should be no longer
|
|
* required. It is unusual to use the instances of this class directly in the
|
|
* user program. Such instances are automatically created and returned by
|
|
* {@link Registry} or {@link UnicastRemoteObject} methods if the remote
|
|
* reference is known but the corresponding stub class is not accessible.
|
|
*
|
|
* @see Registry#lookup
|
|
*
|
|
* @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
|
|
*/
|
|
public class RemoteObjectInvocationHandler extends RemoteObject implements
|
|
InvocationHandler, Remote, Serializable
|
|
{
|
|
/**
|
|
* Use the jdk 1.5 SUID for interoperability.
|
|
*/
|
|
static final long serialVersionUID = 2L;
|
|
|
|
/**
|
|
* The RMI method hash codes, computed once as described in the section 8.3
|
|
* of the Java Remote Method Invocation (RMI) Specification.
|
|
*/
|
|
static Hashtable methodHashCodes = new Hashtable();
|
|
|
|
/**
|
|
* The empty class array to define parameters of .hashCode and .toString.
|
|
*/
|
|
static final Class[] noArgsC = new Class[0];
|
|
|
|
/**
|
|
* The class array to define parameters of .equals
|
|
*/
|
|
static final Class[] anObjectC = new Class[] { Object.class };
|
|
|
|
/**
|
|
* The empty object array to replace null when no args are passed.
|
|
*/
|
|
static final Object[] noArgs = new Object[0];
|
|
|
|
/**
|
|
* Construct the remote invocation handler that forwards calls to the given
|
|
* remote object.
|
|
*
|
|
* @param reference the reference to the remote object where the method
|
|
* calls should be forwarded.
|
|
*/
|
|
public RemoteObjectInvocationHandler(RemoteRef reference)
|
|
{
|
|
super(reference);
|
|
}
|
|
|
|
/**
|
|
* Invoke the remote method. When the known method is invoked on a created RMI
|
|
* stub proxy class, the call is delivered to this method and then transferred
|
|
* to the {@link RemoteRef#invoke(Remote, Method, Object[], long)} of the
|
|
* remote reference that was passed in constructor. The methods are handled as
|
|
* following:
|
|
* <ul>
|
|
* <li> The toString() method is delegated to the passed proxy instance.</li>
|
|
* <li>The .equals method only returns true if the passed object is an
|
|
* instance of proxy class and its invocation handler is equal to this
|
|
* invocation handles.</li>
|
|
* <li>The .hashCode returns the hashCode of this invocation handler (if the.</li>
|
|
* <li>All other methods are converted to remote calls and forwarded to the
|
|
* remote reference. </li>
|
|
* </ul>
|
|
*
|
|
* @param proxyInstance
|
|
* the instance of the proxy stub
|
|
* @param method
|
|
* the method being invoked
|
|
* @param parameters
|
|
* the method parameters
|
|
* @return the method return value, returned by RemoteRef.invoke
|
|
* @throws IllegalAccessException
|
|
* if the passed proxy instance does not implement Remote interface.
|
|
* @throws UnexpectedException
|
|
* if remote call throws some exception, not listed in the
|
|
* <code>throws</code> clause of the method being called.
|
|
* @throws Throwable
|
|
* that is thrown by remote call, if that exception is listend in
|
|
* the <code>throws</code> clause of the method being called.
|
|
*/
|
|
public Object invoke(Object proxyInstance, Method method, Object[] parameters)
|
|
throws Throwable
|
|
{
|
|
if (!(proxyInstance instanceof Remote))
|
|
{
|
|
String name = proxyInstance == null ? "null"
|
|
: proxyInstance.getClass().getName();
|
|
throw new IllegalAccessException(name + " does not implement "
|
|
+ Remote.class.getName());
|
|
}
|
|
|
|
if (parameters == null)
|
|
parameters = noArgs;
|
|
|
|
String name = method.getName();
|
|
switch (name.charAt(0))
|
|
{
|
|
case 'e':
|
|
if (parameters.length == 1 && name.equals("equals")
|
|
&& method.getParameterTypes()[0].equals(Object.class))
|
|
{
|
|
if (parameters[0] instanceof Proxy)
|
|
{
|
|
Object handler = Proxy.getInvocationHandler(parameters[0]);
|
|
if (handler == null)
|
|
return Boolean.FALSE;
|
|
else
|
|
return handler.equals(this) ? Boolean.TRUE : Boolean.FALSE;
|
|
}
|
|
else
|
|
return Boolean.FALSE;
|
|
}
|
|
break;
|
|
case 'h':
|
|
if (parameters.length == 0 && name.equals("hashCode"))
|
|
{
|
|
int hashC = Proxy.getInvocationHandler(proxyInstance).hashCode();
|
|
return new Integer(hashC);
|
|
}
|
|
break;
|
|
case 't':
|
|
if (parameters.length == 0 && name.equals("toString"))
|
|
return "Proxy stub:"+ref.remoteToString();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
Long hash = (Long) methodHashCodes.get(method);
|
|
if (hash == null)
|
|
{
|
|
hash = new Long(RMIHashes.getMethodHash(method));
|
|
methodHashCodes.put(method, hash);
|
|
}
|
|
|
|
try
|
|
{
|
|
return getRef().invoke((Remote) proxyInstance, method, parameters,
|
|
hash.longValue());
|
|
}
|
|
catch (RuntimeException exception)
|
|
{
|
|
// RuntimeException is always supported.
|
|
throw exception;
|
|
}
|
|
catch (RemoteException exception)
|
|
{
|
|
// All remote methods can throw RemoteException.
|
|
throw exception;
|
|
}
|
|
catch (Error exception)
|
|
{
|
|
throw exception;
|
|
}
|
|
catch (Exception exception)
|
|
{
|
|
Class[] exceptions = method.getExceptionTypes();
|
|
Class exceptionClass = exception.getClass();
|
|
|
|
for (int i = 0; i < exceptions.length; i++)
|
|
{
|
|
if (exceptions[i].equals(exceptionClass))
|
|
throw exception;
|
|
}
|
|
throw new UnexpectedException(method.getName(), exception);
|
|
}
|
|
}
|
|
|
|
}
|