java.rmi.server
interface RemoteRef

All Superinterfaces:

Externalizable, Serializable

All Known Subinterfaces:

ServerRef

public interface RemoteRef
extends Externalizable

RemoteRef represents the handle for a remote object. A RemoteStub uses a remote reference to carry out a remote method invocation to a remote object.

packagePrefix

public static final String packagePrefix

Initialize the server package prefix: assumes that the implementation of server ref classes (e.g., UnicastRef, UnicastServerRef) are located in the package defined by the prefix.

serialVersionUID

public static final long serialVersionUID

indicate compatibility with JDK 1.1.x version of class.

done

public void done(RemoteCall call)
          throws RemoteException

Allows the remote reference to clean up (or reuse) the connection. Done should only be called if the invoke returns successfully (non-exceptionally) to the stub.

Parameters:

call - object representing remote call

Throws:

RemoteException - if remote error occurs during call cleanup

getRefClass

public String getRefClass(ObjectOutput out)

Returns the class name of the ref type to be serialized onto the stream 'out'.

Parameters:

out - the output stream to which the reference will be serialized

Returns:

the class name (without package qualification) of the reference type

invoke

public Object invoke(Remote obj,
                     Method method,
                     Object[] params,
                     long opnum)
              throws Exception

Invoke a method. This form of delegating method invocation to the reference allows the reference to take care of setting up the connection to the remote host, marshaling some representation for the method and parameters, then communicating the method invocation to the remote host. This method either returns the result of a method invocation on the remote object which resides on the remote host or throws a RemoteException if the call failed or an application-level exception if the remote invocation throws an exception.

Parameters:

obj - the object that contains the RemoteRef (e.g., the RemoteStub for the object.

method - the method to be invoked

params - the parameter list

opnum - a hash that may be used to represent the method

Returns:

result of remote method invocation

Throws:

Exception - if any exception occurs during remote method invocation

invoke

public void invoke(RemoteCall call)
            throws Exception

Executes the remote call. Invoke will raise any "user" exceptions which should pass through and not be caught by the stub. If any exception is raised during the remote invocation, invoke should take care of cleaning up the connection before raising the "user" or remote exception.

Parameters:

call - object representing remote call

Throws:

Exception - if any exception occurs during remote method

newCall

public RemoteCall newCall(RemoteObject obj,
                          Operation[] op,
                          int opnum,
                          long hash)
                   throws RemoteException

Creates an appropriate call object for a new remote method invocation on this object. Passing operation array and index, allows the stubs generator to assign the operation indexes and interpret them. The remote reference may need the operation to encode in the call.

Parameters:

obj - remote stub through which to make call

op - array of stub operations

opnum - operation number

hash - stub/skeleton interface hash

Returns:

call object representing remote call

Throws:

RemoteException - if failed to initiate new remote call

remoteEquals

public boolean remoteEquals(RemoteRef obj)

Compares two remote objects for equality. Returns a boolean that indicates whether this remote object is equivalent to the specified Object. This method is used when a remote object is stored in a hashtable.

Parameters:

obj - the Object to compare with

Returns:

true if these Objects are equal; false otherwise.

remoteHashCode

public int remoteHashCode()

Returns a hashcode for a remote object. Two remote object stubs that refer to the same remote object will have the same hash code (in order to support remote objects as keys in hash tables).

Returns:

remote object hashcode

remoteToString

public String remoteToString()

Returns a String that represents the reference of this remote object.

Returns:

string representing remote object reference