Java tutorial
/* * Copyright (c) 1996, 2001, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.rmi.registry; import java.rmi.AccessException; import java.rmi.AlreadyBoundException; import java.rmi.NotBoundException; import java.rmi.Remote; import java.rmi.RemoteException; /** * <code>Registry</code> 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 * <code>bind</code>, <code>unbind</code>, and <code>rebind</code> * methods are used to alter the name bindings in the registry, and * the <code>lookup</code> and <code>list</code> methods are used to * query the current name bindings. * * <p>In its typical usage, a <code>Registry</code> 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 {@link * java.rmi.server.ObjID#REGISTRY_ID ObjID} and TCP port number * (default is {@link #REGISTRY_PORT 1099}). * * <p>The {@link LocateRegistry} class provides a programmatic API for * constructing a bootstrap reference to a <code>Registry</code> at a * remote address (see the static <code>getRegistry</code> methods) * and for creating and exporting a <code>Registry</code> in the * current VM on a particular local address (see the static * <code>createRegistry</code> methods). * * <p>A <code>Registry</code> 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 <code>Registry</code> * method chooses to deny access for a given invocation, its * implementation may throw {@link java.rmi.AccessException}, which * (because it extends {@link java.rmi.RemoteException}) will be * wrapped in a {@link java.rmi.ServerException} when caught by a * remote client. * * <p>The names used for bindings in a <code>Registry</code> are pure * strings, not parsed. A service which stores its remote reference * in a <code>Registry</code> may wish to use a package name as a * prefix in the name binding to reduce the likelihood of name * collisions in the registry. * * @author Ann Wollrath * @author Peter Jones * @since 1.1 * @see LocateRegistry */ public interface Registry extends Remote { /** Well known port for registry. */ public static final int REGISTRY_PORT = 1099; /** * Returns the remote reference bound to the specified * <code>name</code> in this registry. * * @param name the name for the remote reference to look up * * @return a reference to a remote object * * @throws NotBoundException if <code>name</code> is not currently bound * * @throws RemoteException if remote communication with the * registry failed; if exception is a <code>ServerException</code> * containing an <code>AccessException</code>, then the registry * denies the caller access to perform this operation * * @throws AccessException if this registry is local and it denies * the caller access to perform this operation * * @throws NullPointerException if <code>name</code> is <code>null</code> */ public Remote lookup(String name) throws RemoteException, NotBoundException, AccessException; /** * Binds a remote reference to the specified <code>name</code> in * this registry. * * @param name the name to associate with the remote reference * @param obj a reference to a remote object (usually a stub) * * @throws AlreadyBoundException if <code>name</code> is already bound * * @throws RemoteException if remote communication with the * registry failed; if exception is a <code>ServerException</code> * containing an <code>AccessException</code>, then the registry * denies the caller access to perform this operation (if * originating from a non-local host, for example) * * @throws AccessException if this registry is local and it denies * the caller access to perform this operation * * @throws NullPointerException if <code>name</code> is * <code>null</code>, or if <code>obj</code> is <code>null</code> */ public void bind(String name, Remote obj) throws RemoteException, AlreadyBoundException, AccessException; /** * Removes the binding for the specified <code>name</code> in * this registry. * * @param name the name of the binding to remove * * @throws NotBoundException if <code>name</code> is not currently bound * * @throws RemoteException if remote communication with the * registry failed; if exception is a <code>ServerException</code> * containing an <code>AccessException</code>, then the registry * denies the caller access to perform this operation (if * originating from a non-local host, for example) * * @throws AccessException if this registry is local and it denies * the caller access to perform this operation * * @throws NullPointerException if <code>name</code> is <code>null</code> */ public void unbind(String name) throws RemoteException, NotBoundException, AccessException; /** * Replaces the binding for the specified <code>name</code> in * this registry with the supplied remote reference. If there is * an existing binding for the specified <code>name</code>, it is * discarded. * * @param name the name to associate with the remote reference * @param obj a reference to a remote object (usually a stub) * * @throws RemoteException if remote communication with the * registry failed; if exception is a <code>ServerException</code> * containing an <code>AccessException</code>, then the registry * denies the caller access to perform this operation (if * originating from a non-local host, for example) * * @throws AccessException if this registry is local and it denies * the caller access to perform this operation * * @throws NullPointerException if <code>name</code> is * <code>null</code>, or if <code>obj</code> is <code>null</code> */ public void rebind(String name, Remote obj) 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. * * @return an array of the names bound in this registry * * @throws RemoteException if remote communication with the * registry failed; if exception is a <code>ServerException</code> * containing an <code>AccessException</code>, then the registry * denies the caller access to perform this operation * * @throws AccessException if this registry is local and it denies * the caller access to perform this operation */ public String[] list() throws RemoteException, AccessException; }