org.openrdf.util.rmirouting
Class ChannelIfaceInvocation

java.lang.Object
  org.openrdf.util.rmirouting.ChannelIfaceInvocation

All Implemented Interfaces:

InvocationHandler

public class ChannelIfaceInvocation

extends Object

implements InvocationHandler

The implementation of client side wraper used to handle and then pass the method invocation requests to the remote side of the channel.

we should notice that all 'void' methods that have only native or Serailizable arguments could be batched and passed at once at some future moment. This can be enable if the wrapped instance implements a Bachable Interface.

The rationale behind this is the assumption that such methods cannot change, in any other way, the state of the invoking context unless they has some very important and significant side effects implemented.

Version:

1.0

Author:

Damyan Ognyanoff

Constructor Summary

ChannelIfaceInvocation(ChannelIface remote, boolean bCanBatch)
the only constructor

Method Summary

Object	invoke(Object proxy, Method method, Object[] args) Handle instance method invocations.
Object	invoke(Object method, Object[] args) a helper which sends the method invocation requests to the remote instance and try to resiolve the return value to some locally stubbed object.
static Object	wrapIt(Object o) A static method used to wrap an remote ref ot an instance.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ChannelIfaceInvocation

public ChannelIfaceInvocation(ChannelIface remote,
                              boolean bCanBatch)

the only constructor

Parameters:

remote - - an instance to which all the 'invoke's are directed

bCanBatch - indicate while to suspend the method batching for that particular instance. It is set to false by the presence of NotBatchable interface into the list of implemented interfaces by the remote instance which is subject of wrapping

Method Detail

wrapIt

public static Object wrapIt(Object o)
                     throws Exception

A static method used to wrap an remote ref ot an instance. Only remote refs implementing ChannelIface will be wrapped

Parameters:

o - is the ref to be wrapped

Returns:

an wraped instance

Throws:

Exception

invoke

public Object invoke(Object method,
                     Object[] args)
              throws Throwable

a helper which sends the method invocation requests to the remote instance and try to resiolve the return value to some locally stubbed object. This is neccessary because we like to avoid multiple wrappings around such objects

Parameters:

method - is the description of the method being invoked

args - are the arguments passed to the method

Returns:

thre value returned by the ral method

Throws:

Throwable - if some exception occur. it will be wrapped into an RemoteException this way, later, we'll be able to get it's 'cause' and rise it locally. All this is an attempt to mimic the remote object's behaviour into the local context from where the method invocaation were originated.

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable

Handle instance method invocations. Here we describe th einvoked method so to be uniquely indentified on th eother side. This description is constructed from the name of the method being invoked followed by the names of the classes of its arguments. The delimiter used to separate these values is '|' character. Once constructed it is coverted to char array - to somehow reduce the net traffic a bit.

Specified by:

invoke in interface InvocationHandler

Parameters:

proxy - - unused here because we like to invoke an remote instance's method

method - - a method being invoked

args - are th earguments passed for the call

Returns:

is what the real method returns from the call.

Throws:

Throwable - it is the exception rised wrom the other side. It is good to use fully serializable exceptions because, if not, they couldn't be transported here at all.