/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/MultihomePlainSocketFactory.java $
* $Revision: 653041 $
* $Date: 2008-05-03 03:39:28 -0700 (Sat, 03 May 2008) $
*
* ====================================================================
* 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.http.conn;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Arrays;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.SocketFactory;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
/**
* Socket factory that implements a simple multi-home fail-over on connect failure,
* provided the same hostname resolves to multiple {@link InetAddress}es. Please note
* the {@link #connectSocket(Socket, String, int, InetAddress, int, HttpParams)}
* method cannot be reliably interrupted by closing the socket returned by the
* {@link #createSocket()} method.
*/
public final class MultihomePlainSocketFactory implements SocketFactory {
/**
* The factory singleton.
*/
private static final
MultihomePlainSocketFactory DEFAULT_FACTORY = new MultihomePlainSocketFactory();
/**
* Gets the singleton instance of this class.
* @return the one and only plain socket factory
*/
public static MultihomePlainSocketFactory getSocketFactory() {
return DEFAULT_FACTORY;
}
/**
* Restricted default constructor.
*/
private MultihomePlainSocketFactory() {
super();
}
// non-javadoc, see interface org.apache.http.conn.SocketFactory
public Socket createSocket() {
return new Socket();
}
/**
* Attempts to connects the socket to any of the {@link InetAddress}es the
* given host name resolves to. If connection to all addresses fail, the
* last I/O exception is propagated to the caller.
*
* @param sock socket to connect to any of the given addresses
* @param host Host name to connect to
* @param port the port to connect to
* @param localAddress local address
* @param localPort local port
* @param params HTTP parameters
*
* @throws IOException if an error occurs during the connection
* @throws SocketTimeoutException if timeout expires before connecting
*/
public Socket connectSocket(Socket sock, String host, int port,
InetAddress localAddress, int localPort,
HttpParams params)
throws IOException {
if (host == null) {
throw new IllegalArgumentException("Target host may not be null.");
}
if (params == null) {
throw new IllegalArgumentException("Parameters may not be null.");
}
if (sock == null)
sock = createSocket();
if ((localAddress != null) || (localPort > 0)) {
// we need to bind explicitly
if (localPort < 0)
localPort = 0; // indicates "any"
InetSocketAddress isa =
new InetSocketAddress(localAddress, localPort);
sock.bind(isa);
}
int timeout = HttpConnectionParams.getConnectionTimeout(params);
InetAddress[] inetadrs = InetAddress.getAllByName(host);
List<InetAddress> addresses = new ArrayList<InetAddress>(inetadrs.length);
addresses.addAll(Arrays.asList(inetadrs));
Collections.shuffle(addresses);
IOException lastEx = null;
for (InetAddress address: addresses) {
try {
sock.connect(new InetSocketAddress(address, port), timeout);
break;
} catch (SocketTimeoutException ex) {
throw ex;
} catch (IOException ex) {
// create new socket
sock = new Socket();
// keep the last exception and retry
lastEx = ex;
}
}
if (lastEx != null) {
throw lastEx;
}
return sock;
} // connectSocket
/**
* Checks whether a socket connection is secure.
* This factory creates plain socket connections
* which are not considered secure.
*
* @param sock the connected socket
*
* @return <code>false</code>
*
* @throws IllegalArgumentException if the argument is invalid
*/
public final boolean isSecure(Socket sock)
throws IllegalArgumentException {
if (sock == null) {
throw new IllegalArgumentException("Socket may not be null.");
}
// This class check assumes that createSocket() calls the constructor
// directly. If it was using javax.net.SocketFactory, we couldn't make
// an assumption about the socket class here.
if (sock.getClass() != Socket.class) {
throw new IllegalArgumentException
("Socket not created by this factory.");
}
// This check is performed last since it calls a method implemented
// by the argument object. getClass() is final in java.lang.Object.
if (sock.isClosed()) {
throw new IllegalArgumentException("Socket is closed.");
}
return false;
} // isSecure
/**
* Compares this factory with an object.
* There is only one instance of this class.
*
* @param obj the object to compare with
*
* @return iff the argument is this object
*/
@Override
public boolean equals(Object obj) {
return (obj == this);
}
/**
* Obtains a hash code for this object.
* All instances of this class have the same hash code.
* There is only one instance of this class.
*/
@Override
public int hashCode() {
return PlainSocketFactory.class.hashCode();
}
}