/*
* ====================================================================
* 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.impl.conn;
import java.io.IOException;
import java.net.ConnectException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.annotation.ThreadSafe;
import org.apache.http.HttpHost;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.HttpHostConnectException;
import org.apache.http.conn.HttpInetSocketAddress;
import org.apache.http.conn.OperatedClientConnection;
import org.apache.http.conn.ClientConnectionOperator;
import org.apache.http.conn.scheme.LayeredSchemeSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.scheme.SchemeSocketFactory;
import org.apache.http.conn.DnsResolver;
/**
* Default implementation of a {@link ClientConnectionOperator}. It uses a {@link SchemeRegistry}
* to look up {@link SchemeSocketFactory} objects.
* <p>
* This connection operator is multihome network aware and will attempt to retry failed connects
* against all known IP addresses sequentially until the connect is successful or all known
* addresses fail to respond. Please note the same
* {@link org.apache.http.params.CoreConnectionPNames#CONNECTION_TIMEOUT} value will be used
* for each connection attempt, so in the worst case the total elapsed time before timeout
* can be <code>CONNECTION_TIMEOUT * n</code> where <code>n</code> is the number of IP addresses
* of the given host. One can disable multihome support by overriding
* the {@link #resolveHostname(String)} method and returning only one IP address for the given
* host name.
* <p>
* The following parameters can be used to customize the behavior of this
* class:
* <ul>
* <li>{@link org.apache.http.params.CoreProtocolPNames#HTTP_ELEMENT_CHARSET}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#SO_TIMEOUT}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#SO_LINGER}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#SO_REUSEADDR}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#TCP_NODELAY}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#SOCKET_BUFFER_SIZE}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#CONNECTION_TIMEOUT}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#MAX_LINE_LENGTH}</li>
* </ul>
*
* @since 4.0
*/
@ThreadSafe
public class DefaultClientConnectionOperator implements ClientConnectionOperator {
private final Log log = LogFactory.getLog(getClass());
/** The scheme registry for looking up socket factories. */
protected final SchemeRegistry schemeRegistry; // @ThreadSafe
/** the custom-configured DNS lookup mechanism. */
protected final DnsResolver dnsResolver;
/**
* Creates a new client connection operator for the given scheme registry.
*
* @param schemes the scheme registry
*
* @since 4.2
*/
public DefaultClientConnectionOperator(final SchemeRegistry schemes) {
if (schemes == null) {
throw new IllegalArgumentException("Scheme registry amy not be null");
}
this.schemeRegistry = schemes;
this.dnsResolver = new SystemDefaultDnsResolver();
}
/**
* Creates a new client connection operator for the given scheme registry
* and the given custom DNS lookup mechanism.
*
* @param schemes
* the scheme registry
* @param dnsResolver
* the custom DNS lookup mechanism
*/
public DefaultClientConnectionOperator(final SchemeRegistry schemes,final DnsResolver dnsResolver) {
if (schemes == null) {
throw new IllegalArgumentException(
"Scheme registry may not be null");
}
if(dnsResolver == null){
throw new IllegalArgumentException("DNS resolver may not be null");
}
this.schemeRegistry = schemes;
this.dnsResolver = dnsResolver;
}
public OperatedClientConnection createConnection() {
return new DefaultClientConnection();
}
public void openConnection(
final OperatedClientConnection conn,
final HttpHost target,
final InetAddress local,
final HttpContext context,
final HttpParams params) throws IOException {
if (conn == null) {
throw new IllegalArgumentException("Connection may not be null");
}
if (target == null) {
throw new IllegalArgumentException("Target host may not be null");
}
if (params == null) {
throw new IllegalArgumentException("Parameters may not be null");
}
if (conn.isOpen()) {
throw new IllegalStateException("Connection must not be open");
}
Scheme schm = schemeRegistry.getScheme(target.getSchemeName());
SchemeSocketFactory sf = schm.getSchemeSocketFactory();
InetAddress[] addresses = resolveHostname(target.getHostName());
int port = schm.resolvePort(target.getPort());
for (int i = 0; i < addresses.length; i++) {
InetAddress address = addresses[i];
boolean last = i == addresses.length - 1;
Socket sock = sf.createSocket(params);
conn.opening(sock, target);
InetSocketAddress remoteAddress = new HttpInetSocketAddress(target, address, port);
InetSocketAddress localAddress = null;
if (local != null) {
localAddress = new InetSocketAddress(local, 0);
}
if (this.log.isDebugEnabled()) {
this.log.debug("Connecting to " + remoteAddress);
}
try {
Socket connsock = sf.connectSocket(sock, remoteAddress, localAddress, params);
if (sock != connsock) {
sock = connsock;
conn.opening(sock, target);
}
prepareSocket(sock, context, params);
conn.openCompleted(sf.isSecure(sock), params);
return;
} catch (ConnectException ex) {
if (last) {
throw new HttpHostConnectException(target, ex);
}
} catch (ConnectTimeoutException ex) {
if (last) {
throw ex;
}
}
if (this.log.isDebugEnabled()) {
this.log.debug("Connect to " + remoteAddress + " timed out. " +
"Connection will be retried using another IP address");
}
}
}
public void updateSecureConnection(
final OperatedClientConnection conn,
final HttpHost target,
final HttpContext context,
final HttpParams params) throws IOException {
if (conn == null) {
throw new IllegalArgumentException("Connection may not be null");
}
if (target == null) {
throw new IllegalArgumentException("Target host may not be null");
}
if (params == null) {
throw new IllegalArgumentException("Parameters may not be null");
}
if (!conn.isOpen()) {
throw new IllegalStateException("Connection must be open");
}
final Scheme schm = schemeRegistry.getScheme(target.getSchemeName());
if (!(schm.getSchemeSocketFactory() instanceof LayeredSchemeSocketFactory)) {
throw new IllegalArgumentException
("Target scheme (" + schm.getName() +
") must have layered socket factory.");
}
LayeredSchemeSocketFactory lsf = (LayeredSchemeSocketFactory) schm.getSchemeSocketFactory();
Socket sock;
try {
sock = lsf.createLayeredSocket(
conn.getSocket(), target.getHostName(), target.getPort(), true);
} catch (ConnectException ex) {
throw new HttpHostConnectException(target, ex);
}
prepareSocket(sock, context, params);
conn.update(sock, target, lsf.isSecure(sock), params);
}
/**
* Performs standard initializations on a newly created socket.
*
* @param sock the socket to prepare
* @param context the context for the connection
* @param params the parameters from which to prepare the socket
*
* @throws IOException in case of an IO problem
*/
protected void prepareSocket(
final Socket sock,
final HttpContext context,
final HttpParams params) throws IOException {
sock.setTcpNoDelay(HttpConnectionParams.getTcpNoDelay(params));
sock.setSoTimeout(HttpConnectionParams.getSoTimeout(params));
int linger = HttpConnectionParams.getLinger(params);
if (linger >= 0) {
sock.setSoLinger(linger > 0, linger);
}
}
/**
* Resolves the given host name to an array of corresponding IP addresses, based on the
* configured name service on the provided DNS resolver. If one wasn't provided, the system
* configuration is used.
*
* @param host host name to resolve
* @return array of IP addresses
* @exception UnknownHostException if no IP address for the host could be determined.
*
* @see DnsResolver
* @see SystemDefaultDnsResolver
*
* @since 4.1
*/
protected InetAddress[] resolveHostname(final String host) throws UnknownHostException {
return dnsResolver.resolve(host);
}
}