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:
1.1
See Also:

  • Field Summary

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

  • Method Summary

    Modifier and Type
    Method
    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 Details

    • REGISTRY_PORT

      static final int REGISTRY_PORT
      Well known port for registry.
      See Also:

  • Method Details

    • 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