Java tutorial
/* * Copyright (c) 1996, 2003, 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.RemoteException; import java.rmi.server.ObjID; import java.rmi.server.RMIClientSocketFactory; import java.rmi.server.RMIServerSocketFactory; import java.rmi.server.RemoteRef; import java.rmi.server.UnicastRemoteObject; import sun.rmi.registry.RegistryImpl; import sun.rmi.server.UnicastRef2; import sun.rmi.server.UnicastRef; import sun.rmi.server.Util; import sun.rmi.transport.LiveRef; import sun.rmi.transport.tcp.TCPEndpoint; /** * <code>LocateRegistry</code> is used to obtain a reference to a bootstrap * remote object registry on a particular host (including the local host), or * to create a remote object registry that accepts calls on a specific port. * * <p> Note that a <code>getRegistry</code> call does not actually make a * connection to the remote host. It simply creates a local reference to * the remote registry and will succeed even if no registry is running on * the remote host. Therefore, a subsequent method invocation to a remote * registry returned as a result of this method may fail. * * @author Ann Wollrath * @author Peter Jones * @since 1.1 * @see java.rmi.registry.Registry */ public final class LocateRegistry { /** * Private constructor to disable public construction. */ private LocateRegistry() { } /** * Returns a reference to the remote object <code>Registry</code> for * the local host on the default registry port of 1099. * * @return reference (a stub) to the remote object registry * @exception RemoteException if the reference could not be created * @since 1.1 */ public static Registry getRegistry() throws RemoteException { return getRegistry(null, Registry.REGISTRY_PORT); } /** * Returns a reference to the remote object <code>Registry</code> for * the local host on the specified <code>port</code>. * * @param port port on which the registry accepts requests * @return reference (a stub) to the remote object registry * @exception RemoteException if the reference could not be created * @since 1.1 */ public static Registry getRegistry(int port) throws RemoteException { return getRegistry(null, port); } /** * Returns a reference to the remote object <code>Registry</code> on the * specified <code>host</code> on the default registry port of 1099. If * <code>host</code> is <code>null</code>, the local host is used. * * @param host host for the remote registry * @return reference (a stub) to the remote object registry * @exception RemoteException if the reference could not be created * @since 1.1 */ public static Registry getRegistry(String host) throws RemoteException { return getRegistry(host, Registry.REGISTRY_PORT); } /** * Returns a reference to the remote object <code>Registry</code> on the * specified <code>host</code> and <code>port</code>. If <code>host</code> * is <code>null</code>, the local host is used. * * @param host host for the remote registry * @param port port on which the registry accepts requests * @return reference (a stub) to the remote object registry * @exception RemoteException if the reference could not be created * @since 1.1 */ public static Registry getRegistry(String host, int port) throws RemoteException { return getRegistry(host, port, null); } /** * Returns a locally created remote reference to the remote object * <code>Registry</code> on the specified <code>host</code> and * <code>port</code>. Communication with this remote registry will * use the supplied <code>RMIClientSocketFactory</code> <code>csf</code> * to create <code>Socket</code> connections to the registry on the * remote <code>host</code> and <code>port</code>. * * @param host host for the remote registry * @param port port on which the registry accepts requests * @param csf client-side <code>Socket</code> factory used to * make connections to the registry. If <code>csf</code> * is null, then the default client-side <code>Socket</code> * factory will be used in the registry stub. * @return reference (a stub) to the remote registry * @exception RemoteException if the reference could not be created * @since 1.2 */ public static Registry getRegistry(String host, int port, RMIClientSocketFactory csf) throws RemoteException { Registry registry = null; if (port <= 0) port = Registry.REGISTRY_PORT; if (host == null || host.length() == 0) { // If host is blank (as returned by "file:" URL in 1.0.2 used in // java.rmi.Naming), try to convert to real local host name so // that the RegistryImpl's checkAccess will not fail. try { host = java.net.InetAddress.getLocalHost().getHostAddress(); } catch (Exception e) { // If that failed, at least try "" (localhost) anyway... host = ""; } } /* * Create a proxy for the registry with the given host, port, and * client socket factory. If the supplied client socket factory is * null, then the ref type is a UnicastRef, otherwise the ref type * is a UnicastRef2. If the property * java.rmi.server.ignoreStubClasses is true, then the proxy * returned is an instance of a dynamic proxy class that implements * the Registry interface; otherwise the proxy returned is an * instance of the pregenerated stub class for RegistryImpl. **/ LiveRef liveRef = new LiveRef(new ObjID(ObjID.REGISTRY_ID), new TCPEndpoint(host, port, csf, null), false); RemoteRef ref = (csf == null) ? new UnicastRef(liveRef) : new UnicastRef2(liveRef); return (Registry) Util.createProxy(RegistryImpl.class, ref, false); } /** * Creates and exports a <code>Registry</code> instance on the local * host that accepts requests on the specified <code>port</code>. * * <p>The <code>Registry</code> instance is exported as if the static * {@link UnicastRemoteObject#exportObject(Remote,int) * UnicastRemoteObject.exportObject} method is invoked, passing the * <code>Registry</code> instance and the specified <code>port</code> as * arguments, except that the <code>Registry</code> instance is * exported with a well-known object identifier, an {@link ObjID} * instance constructed with the value {@link ObjID#REGISTRY_ID}. * * @param port the port on which the registry accepts requests * @return the registry * @exception RemoteException if the registry could not be exported * @since 1.1 **/ public static Registry createRegistry(int port) throws RemoteException { return new RegistryImpl(port); } /** * Creates and exports a <code>Registry</code> instance on the local * host that uses custom socket factories for communication with that * instance. The registry that is created listens for incoming * requests on the given <code>port</code> using a * <code>ServerSocket</code> created from the supplied * <code>RMIServerSocketFactory</code>. * * <p>The <code>Registry</code> instance is exported as if * the static {@link * UnicastRemoteObject#exportObject(Remote,int,RMIClientSocketFactory,RMIServerSocketFactory) * UnicastRemoteObject.exportObject} method is invoked, passing the * <code>Registry</code> instance, the specified <code>port</code>, the * specified <code>RMIClientSocketFactory</code>, and the specified * <code>RMIServerSocketFactory</code> as arguments, except that the * <code>Registry</code> instance is exported with a well-known object * identifier, an {@link ObjID} instance constructed with the value * {@link ObjID#REGISTRY_ID}. * * @param port port on which the registry accepts requests * @param csf client-side <code>Socket</code> factory used to * make connections to the registry * @param ssf server-side <code>ServerSocket</code> factory * used to accept connections to the registry * @return the registry * @exception RemoteException if the registry could not be exported * @since 1.2 **/ public static Registry createRegistry(int port, RMIClientSocketFactory csf, RMIServerSocketFactory ssf) throws RemoteException { return new RegistryImpl(port, csf, ssf); } }