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.
LocateRegistry
Modifier and Type | Field and Description |
---|---|
static int |
REGISTRY_PORT
Well known port for registry.
|
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. |
static final int REGISTRY_PORT
Remote lookup(String name) throws RemoteException, NotBoundException, AccessException
name
in this registry.name
- the name for the remote reference to look upNotBoundException
- if name
is not currently boundRemoteException
- 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 operationAccessException
- if this registry is local and it denies
the caller access to perform this operationNullPointerException
- if name
is null
void bind(String name, Remote obj) throws RemoteException, AlreadyBoundException, AccessException
name
in
this registry.name
- the name to associate with the remote referenceobj
- a reference to a remote object (usually a stub)AlreadyBoundException
- if name
is already boundRemoteException
- 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 operationNullPointerException
- if name
is
null
, or if obj
is null
void unbind(String name) throws RemoteException, NotBoundException, AccessException
name
in
this registry.name
- the name of the binding to removeNotBoundException
- if name
is not currently boundRemoteException
- 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 operationNullPointerException
- if name
is null
void rebind(String name, Remote obj) throws RemoteException, AccessException
name
in
this registry with the supplied remote reference. If there is
an existing binding for the specified name
, it is
discarded.name
- the name to associate with the remote referenceobj
- a reference to a remote object (usually a stub)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 operationNullPointerException
- if name
is
null
, or if obj
is null
String[] list() throws RemoteException, AccessException
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 operationAccessException
- if this registry is local and it denies
the caller access to perform this operation Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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