/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/protocol/ReflectionSocketFactory.java,v 1.4 2004/12/21 23:15:21 olegk Exp $
* $Revision: 480424 $
* $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
*
* ====================================================================
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.commons.httpclient.protocol;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import org.apache.commons.httpclient.ConnectTimeoutException;
/**
* This helper class uses refelction in order to execute Socket methods
* available in Java 1.4 and above
*
* @author Oleg Kalnichevski
*
* @since 3.0
*/
public final class ReflectionSocketFactory {
private static boolean REFLECTION_FAILED = false;
private static Constructor INETSOCKETADDRESS_CONSTRUCTOR = null;
private static Method SOCKETCONNECT_METHOD = null;
private static Method SOCKETBIND_METHOD = null;
private static Class SOCKETTIMEOUTEXCEPTION_CLASS = null;
private ReflectionSocketFactory() {
super();
}
/**
* This method attempts to execute Socket method available since Java 1.4
* using reflection. If the methods are not available or could not be executed
* <tt>null</tt> is returned
*
* @param socketfactoryName name of the socket factory class
* @param host the host name/IP
* @param port the port on the host
* @param localAddress the local host name/IP to bind the socket to
* @param localPort the port on the local machine
* @param timeout the timeout value to be used in milliseconds. If the socket cannot be
* completed within the given time limit, it will be abandoned
*
* @return a connected Socket
*
* @throws IOException if an I/O error occurs while creating the socket
* @throws UnknownHostException if the IP address of the host cannot be
* determined
* @throws ConnectTimeoutException if socket cannot be connected within the
* given time limit
*
*/
public static Socket createSocket(
final String socketfactoryName,
final String host,
final int port,
final InetAddress localAddress,
final int localPort,
int timeout)
throws IOException, UnknownHostException, ConnectTimeoutException
{
if (REFLECTION_FAILED) {
//This is known to have failed before. Do not try it again
return null;
}
// This code uses reflection to essentially do the following:
//
// SocketFactory socketFactory = Class.forName(socketfactoryName).getDefault();
// Socket socket = socketFactory.createSocket();
// SocketAddress localaddr = new InetSocketAddress(localAddress, localPort);
// SocketAddress remoteaddr = new InetSocketAddress(host, port);
// socket.bind(localaddr);
// socket.connect(remoteaddr, timeout);
// return socket;
try {
Class socketfactoryClass = Class.forName(socketfactoryName);
Method method = socketfactoryClass.getMethod("getDefault",
new Class[] {});
Object socketfactory = method.invoke(null,
new Object[] {});
method = socketfactoryClass.getMethod("createSocket",
new Class[] {});
Socket socket = (Socket) method.invoke(socketfactory, new Object[] {});
if (INETSOCKETADDRESS_CONSTRUCTOR == null) {
Class addressClass = Class.forName("java.net.InetSocketAddress");
INETSOCKETADDRESS_CONSTRUCTOR = addressClass.getConstructor(
new Class[] { InetAddress.class, Integer.TYPE });
}
Object remoteaddr = INETSOCKETADDRESS_CONSTRUCTOR.newInstance(
new Object[] { InetAddress.getByName(host), new Integer(port)});
Object localaddr = INETSOCKETADDRESS_CONSTRUCTOR.newInstance(
new Object[] { localAddress, new Integer(localPort)});
if (SOCKETCONNECT_METHOD == null) {
SOCKETCONNECT_METHOD = Socket.class.getMethod("connect",
new Class[] {Class.forName("java.net.SocketAddress"), Integer.TYPE});
}
if (SOCKETBIND_METHOD == null) {
SOCKETBIND_METHOD = Socket.class.getMethod("bind",
new Class[] {Class.forName("java.net.SocketAddress")});
}
SOCKETBIND_METHOD.invoke(socket, new Object[] { localaddr});
SOCKETCONNECT_METHOD.invoke(socket, new Object[] { remoteaddr, new Integer(timeout)});
return socket;
}
catch (InvocationTargetException e) {
Throwable cause = e.getTargetException();
if (SOCKETTIMEOUTEXCEPTION_CLASS == null) {
try {
SOCKETTIMEOUTEXCEPTION_CLASS = Class.forName("java.net.SocketTimeoutException");
} catch (ClassNotFoundException ex) {
// At this point this should never happen. Really.
REFLECTION_FAILED = true;
return null;
}
}
if (SOCKETTIMEOUTEXCEPTION_CLASS.isInstance(cause)) {
throw new ConnectTimeoutException(
"The host did not accept the connection within timeout of "
+ timeout + " ms", cause);
}
if (cause instanceof IOException) {
throw (IOException)cause;
}
return null;
}
catch (Exception e) {
REFLECTION_FAILED = true;
return null;
}
}
}