Registry
implements Remote| java.rmi.registry.Registry |
 Known Indirect Subclasses
|
Class Overview
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.
See Also
Summary
| Constants | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| int | REGISTRY_PORT | Well known port for registry. | |||||||||
| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Binds a remote reference to the specified
name in
this registry. | |||||||||||
Returns an array of the names bound in this registry.
| |||||||||||
Returns the remote reference bound to the specified
name in this registry. | |||||||||||
Replaces the binding for the specified
name in
this registry with the supplied remote reference. | |||||||||||
Removes the binding for the specified
name in
this registry. | |||||||||||
Constants
public static final int REGISTRY_PORT
Well known port for registry.
Public Methods
public abstract void bind (String name, Remote obj)
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
|
public abstract String[] list ()
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 |
public abstract Remote lookup (String name)
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
|
public abstract void rebind (String name, Remote obj)
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
|
public abstract void unbind (String name)
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
|