java.rmi.registry

Interface Registry

All Superinterfaces:

Remote

public interface Registry
extends Remote

Registry is a remote interface to a simple remote object registry that provides methods for storing and retrieving remote object references bound with arbitrary string names. The bind, unbind, and rebind methods are used to alter the name bindings in the registry, and the lookup and list methods are used to query the current name bindings.

In its typical usage, a Registry enables RMI client bootstrapping: it provides a simple means for a client to obtain an initial reference to a remote object. Therefore, a registry's remote object implementation is typically exported with a well-known address, such as with a well-known ObjID and TCP port number (default is 1099).

The LocateRegistry class provides a programmatic API for constructing a bootstrap reference to a Registry at a remote address (see the static getRegistry methods) and for creating and exporting a Registry in the current VM on a particular local address (see the static createRegistry methods).

A Registry implementation may choose to restrict access to some or all of its methods (for example, methods that mutate the registry's bindings may be restricted to calls originating from the local host). If a Registry method chooses to deny access for a given invocation, its implementation may throw AccessException, which (because it extends RemoteException) will be wrapped in a ServerException when caught by a remote client.

The names used for bindings in a Registry are pure strings, not parsed. A service which stores its remote reference in a Registry may wish to use a package name as a prefix in the name binding to reduce the likelihood of name collisions in the registry.

Since:

JDK1.1

See Also:

LocateRegistry

Field Summary

Fields

Modifier and Type	Field and Description
static int	REGISTRY_PORT Well known port for registry.

Method Summary

Methods

Modifier and Type	Method and Description
void	bind(String name, Remote obj) Binds a remote reference to the specified name in this registry.
String[]	list() Returns an array of the names bound in this registry.
Remote	lookup(String name) Returns the remote reference bound to the specified name in this registry.
void	rebind(String name, Remote obj) Replaces the binding for the specified name in this registry with the supplied remote reference.
void	unbind(String name) Removes the binding for the specified name in this registry.

Field Detail

REGISTRY_PORT

static final int REGISTRY_PORT

Well known port for registry.

See Also:

Constant Field Values

Method Detail

lookup

Remote lookup(String name)
              throws RemoteException,
                     NotBoundException,
                     AccessException

Returns the remote reference bound to the specified name in this registry.

Parameters:

name - the name for the remote reference to look up

Returns:

a reference to a remote object

Throws:

NotBoundException - if name is not currently bound

RemoteException - if remote communication with the registry failed; if exception is a ServerException containing an AccessException, then the registry denies the caller access to perform this operation

AccessException - if this registry is local and it denies the caller access to perform this operation

NullPointerException - if name is null

bind

void bind(String name,
        Remote obj)
          throws RemoteException,
                 AlreadyBoundException,
                 AccessException

Binds a remote reference to the specified name in this registry.

Parameters:

name - the name to associate with the remote reference

obj - a reference to a remote object (usually a stub)

Throws:

AlreadyBoundException - if name is already bound

RemoteException - if remote communication with the registry failed; if exception is a ServerException containing an AccessException, then the registry denies the caller access to perform this operation (if originating from a non-local host, for example)

AccessException - if this registry is local and it denies the caller access to perform this operation

NullPointerException - if name is null, or if obj is null

unbind

void unbind(String name)
            throws RemoteException,
                   NotBoundException,
                   AccessException

Removes the binding for the specified name in this registry.

Parameters:

name - the name of the binding to remove

Throws:

NotBoundException - if name is not currently bound

RemoteException - if remote communication with the registry failed; if exception is a ServerException containing an AccessException, then the registry denies the caller access to perform this operation (if originating from a non-local host, for example)

AccessException - if this registry is local and it denies the caller access to perform this operation

NullPointerException - if name is null

rebind

void rebind(String name,
          Remote obj)
            throws RemoteException,
                   AccessException

Replaces the binding for the specified name in this registry with the supplied remote reference. If there is an existing binding for the specified name, it is discarded.

Parameters:

name - the name to associate with the remote reference

obj - a reference to a remote object (usually a stub)

Throws:

RemoteException - if remote communication with the registry failed; if exception is a ServerException containing an AccessException, then the registry denies the caller access to perform this operation (if originating from a non-local host, for example)

AccessException - if this registry is local and it denies the caller access to perform this operation

NullPointerException - if name is null, or if obj is null

list

String[] list()
              throws RemoteException,
                     AccessException

Returns an array of the names bound in this registry. The array will contain a snapshot of the names bound in this registry at the time of the given invocation of this method.

Returns:

an array of the names bound in this registry

Throws:

RemoteException - if remote communication with the registry failed; if exception is a ServerException containing an AccessException, then the registry denies the caller access to perform this operation

AccessException - if this registry is local and it denies the caller access to perform this operation