J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2002 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.rmi.server; |
| 27 | |
| 28 | import java.io.*; |
| 29 | import java.net.*; |
| 30 | |
| 31 | /** |
| 32 | * An <code>RMISocketFactory</code> instance is used by the RMI runtime |
| 33 | * in order to obtain client and server sockets for RMI calls. An |
| 34 | * application may use the <code>setSocketFactory</code> method to |
| 35 | * request that the RMI runtime use its socket factory instance |
| 36 | * instead of the default implementation.<p> |
| 37 | * |
| 38 | * The default socket factory implementation used goes through a |
| 39 | * three-tiered approach to creating client sockets. First, a direct |
| 40 | * socket connection to the remote VM is attempted. If that fails |
| 41 | * (due to a firewall), the runtime uses HTTP with the explicit port |
| 42 | * number of the server. If the firewall does not allow this type of |
| 43 | * communication, then HTTP to a cgi-bin script on the server is used |
| 44 | * to POST the RMI call.<p> |
| 45 | * |
| 46 | * @author Ann Wollrath |
| 47 | * @author Peter Jones |
| 48 | * @since JDK1.1 |
| 49 | */ |
| 50 | public abstract class RMISocketFactory |
| 51 | implements RMIClientSocketFactory, RMIServerSocketFactory |
| 52 | { |
| 53 | |
| 54 | /** Client/server socket factory to be used by RMI runtime */ |
| 55 | private static RMISocketFactory factory = null; |
| 56 | /** default socket factory used by this RMI implementation */ |
| 57 | private static RMISocketFactory defaultSocketFactory; |
| 58 | /** Handler for socket creation failure */ |
| 59 | private static RMIFailureHandler handler = null; |
| 60 | |
| 61 | /** |
| 62 | * Constructs an <code>RMISocketFactory</code>. |
| 63 | * @since JDK1.1 |
| 64 | */ |
| 65 | public RMISocketFactory() { |
| 66 | super(); |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Creates a client socket connected to the specified host and port. |
| 71 | * @param host the host name |
| 72 | * @param port the port number |
| 73 | * @return a socket connected to the specified host and port. |
| 74 | * @exception IOException if an I/O error occurs during socket creation |
| 75 | * @since JDK1.1 |
| 76 | */ |
| 77 | public abstract Socket createSocket(String host, int port) |
| 78 | throws IOException; |
| 79 | |
| 80 | /** |
| 81 | * Create a server socket on the specified port (port 0 indicates |
| 82 | * an anonymous port). |
| 83 | * @param port the port number |
| 84 | * @return the server socket on the specified port |
| 85 | * @exception IOException if an I/O error occurs during server socket |
| 86 | * creation |
| 87 | * @since JDK1.1 |
| 88 | */ |
| 89 | public abstract ServerSocket createServerSocket(int port) |
| 90 | throws IOException; |
| 91 | |
| 92 | /** |
| 93 | * Set the global socket factory from which RMI gets sockets (if the |
| 94 | * remote object is not associated with a specific client and/or server |
| 95 | * socket factory). The RMI socket factory can only be set once. Note: The |
| 96 | * RMISocketFactory may only be set if the current security manager allows |
| 97 | * setting a socket factory; if disallowed, a SecurityException will be |
| 98 | * thrown. |
| 99 | * @param fac the socket factory |
| 100 | * @exception IOException if the RMI socket factory is already set |
| 101 | * @exception SecurityException if a security manager exists and its |
| 102 | * <code>checkSetFactory</code> method doesn't allow the operation. |
| 103 | * @see #getSocketFactory |
| 104 | * @see java.lang.SecurityManager#checkSetFactory() |
| 105 | * @since JDK1.1 |
| 106 | */ |
| 107 | public synchronized static void setSocketFactory(RMISocketFactory fac) |
| 108 | throws IOException |
| 109 | { |
| 110 | if (factory != null) { |
| 111 | throw new SocketException("factory already defined"); |
| 112 | } |
| 113 | SecurityManager security = System.getSecurityManager(); |
| 114 | if (security != null) { |
| 115 | security.checkSetFactory(); |
| 116 | } |
| 117 | factory = fac; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Returns the socket factory set by the <code>setSocketFactory</code> |
| 122 | * method. Returns <code>null</code> if no socket factory has been |
| 123 | * set. |
| 124 | * @return the socket factory |
| 125 | * @see #setSocketFactory(RMISocketFactory) |
| 126 | * @since JDK1.1 |
| 127 | */ |
| 128 | public synchronized static RMISocketFactory getSocketFactory() |
| 129 | { |
| 130 | return factory; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Returns a reference to the default socket factory used |
| 135 | * by this RMI implementation. This will be the factory used |
| 136 | * by the RMI runtime when <code>getSocketFactory</code> |
| 137 | * returns <code>null</code>. |
| 138 | * @return the default RMI socket factory |
| 139 | * @since JDK1.1 |
| 140 | */ |
| 141 | public synchronized static RMISocketFactory getDefaultSocketFactory() { |
| 142 | if (defaultSocketFactory == null) { |
| 143 | defaultSocketFactory = |
| 144 | new sun.rmi.transport.proxy.RMIMasterSocketFactory(); |
| 145 | } |
| 146 | return defaultSocketFactory; |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Sets the failure handler to be called by the RMI runtime if server |
| 151 | * socket creation fails. By default, if no failure handler is installed |
| 152 | * and server socket creation fails, the RMI runtime does attempt to |
| 153 | * recreate the server socket. |
| 154 | * |
| 155 | * <p>If there is a security manager, this method first calls |
| 156 | * the security manager's <code>checkSetFactory</code> method |
| 157 | * to ensure the operation is allowed. |
| 158 | * This could result in a <code>SecurityException</code>. |
| 159 | * |
| 160 | * @param fh the failure handler |
| 161 | * @throws SecurityException if a security manager exists and its |
| 162 | * <code>checkSetFactory</code> method doesn't allow the |
| 163 | * operation. |
| 164 | * @see #getFailureHandler |
| 165 | * @see java.rmi.server.RMIFailureHandler#failure(Exception) |
| 166 | * @since JDK1.1 |
| 167 | */ |
| 168 | public synchronized static void setFailureHandler(RMIFailureHandler fh) |
| 169 | { |
| 170 | SecurityManager security = System.getSecurityManager(); |
| 171 | if (security != null) { |
| 172 | security.checkSetFactory(); |
| 173 | } |
| 174 | handler = fh; |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Returns the handler for socket creation failure set by the |
| 179 | * <code>setFailureHandler</code> method. |
| 180 | * @return the failure handler |
| 181 | * @see #setFailureHandler(RMIFailureHandler) |
| 182 | * @since JDK1.1 |
| 183 | */ |
| 184 | public synchronized static RMIFailureHandler getFailureHandler() |
| 185 | { |
| 186 | return handler; |
| 187 | } |
| 188 | } |