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* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
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* 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.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.List;
import org.apache.http.annotation.NotThreadSafe;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.protocol.HttpContext;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.routing.HttpRoutePlanner;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.params.ConnRouteParams;
/**
* Default implementation of an {@link HttpRoutePlanner}.
* This implementation is based on {@link java.net.ProxySelector}.
* By default, it will pick up the proxy settings of the JVM, either
* from system properties or from the browser running the application.
* Additionally, it interprets some
* {@link org.apache.http.conn.params.ConnRoutePNames parameters},
* though not the {@link
* org.apache.http.conn.params.ConnRoutePNames#DEFAULT_PROXY DEFAULT_PROXY}.
* <p>
* The following parameters can be used to customize the behavior of this
* class:
* <ul>
* <li>{@link org.apache.http.conn.params.ConnRoutePNames#LOCAL_ADDRESS}</li>
* <li>{@link org.apache.http.conn.params.ConnRoutePNames#FORCED_ROUTE}</li>
* </ul>
*
* @since 4.0
*/
@NotThreadSafe // e.g [gs]etProxySelector()
public class ProxySelectorRoutePlanner implements HttpRoutePlanner {
/** The scheme registry. */
protected final SchemeRegistry schemeRegistry; // @ThreadSafe
/** The proxy selector to use, or <code>null</code> for system default. */
protected ProxySelector proxySelector;
/**
* Creates a new proxy selector route planner.
*
* @param schreg the scheme registry
* @param prosel the proxy selector, or
* <code>null</code> for the system default
*/
public ProxySelectorRoutePlanner(SchemeRegistry schreg,
ProxySelector prosel) {
if (schreg == null) {
throw new IllegalArgumentException
("SchemeRegistry must not be null.");
}
schemeRegistry = schreg;
proxySelector = prosel;
}
/**
* Obtains the proxy selector to use.
*
* @return the proxy selector, or <code>null</code> for the system default
*/
public ProxySelector getProxySelector() {
return this.proxySelector;
}
/**
* Sets the proxy selector to use.
*
* @param prosel the proxy selector, or
* <code>null</code> to use the system default
*/
public void setProxySelector(ProxySelector prosel) {
this.proxySelector = prosel;
}
public HttpRoute determineRoute(HttpHost target,
HttpRequest request,
HttpContext context)
throws HttpException {
if (request == null) {
throw new IllegalStateException
("Request must not be null.");
}
// If we have a forced route, we can do without a target.
HttpRoute route =
ConnRouteParams.getForcedRoute(request.getParams());
if (route != null)
return route;
// If we get here, there is no forced route.
// So we need a target to compute a route.
if (target == null) {
throw new IllegalStateException
("Target host must not be null.");
}
final InetAddress local =
ConnRouteParams.getLocalAddress(request.getParams());
final HttpHost proxy = determineProxy(target, request, context);
final Scheme schm =
this.schemeRegistry.getScheme(target.getSchemeName());
// as it is typically used for TLS/SSL, we assume that
// a layered scheme implies a secure connection
final boolean secure = schm.isLayered();
if (proxy == null) {
route = new HttpRoute(target, local, secure);
} else {
route = new HttpRoute(target, local, proxy, secure);
}
return route;
}
/**
* Determines a proxy for the given target.
*
* @param target the planned target, never <code>null</code>
* @param request the request to be sent, never <code>null</code>
* @param context the context, or <code>null</code>
*
* @return the proxy to use, or <code>null</code> for a direct route
*
* @throws HttpException
* in case of system proxy settings that cannot be handled
*/
protected HttpHost determineProxy(HttpHost target,
HttpRequest request,
HttpContext context)
throws HttpException {
// the proxy selector can be 'unset', so we better deal with null here
ProxySelector psel = this.proxySelector;
if (psel == null)
psel = ProxySelector.getDefault();
if (psel == null)
return null;
URI targetURI = null;
try {
targetURI = new URI(target.toURI());
} catch (URISyntaxException usx) {
throw new HttpException
("Cannot convert host to URI: " + target, usx);
}
List<Proxy> proxies = psel.select(targetURI);
Proxy p = chooseProxy(proxies, target, request, context);
HttpHost result = null;
if (p.type() == Proxy.Type.HTTP) {
// convert the socket address to an HttpHost
if (!(p.address() instanceof InetSocketAddress)) {
throw new HttpException
("Unable to handle non-Inet proxy address: "+p.address());
}
final InetSocketAddress isa = (InetSocketAddress) p.address();
// assume default scheme (http)
result = new HttpHost(getHost(isa), isa.getPort());
}
return result;
}
/**
* Obtains a host from an {@link InetSocketAddress}.
*
* @param isa the socket address
*
* @return a host string, either as a symbolic name or
* as a literal IP address string
* <br/>
* (TODO: determine format for IPv6 addresses, with or without [brackets])
*/
protected String getHost(InetSocketAddress isa) {
//@@@ Will this work with literal IPv6 addresses, or do we
//@@@ need to wrap these in [] for the string representation?
//@@@ Having it in this method at least allows for easy workarounds.
return isa.isUnresolved() ?
isa.getHostName() : isa.getAddress().getHostAddress();
}
/**
* Chooses a proxy from a list of available proxies.
* The default implementation just picks the first non-SOCKS proxy
* from the list. If there are only SOCKS proxies,
* {@link Proxy#NO_PROXY Proxy.NO_PROXY} is returned.
* Derived classes may implement more advanced strategies,
* such as proxy rotation if there are multiple options.
*
* @param proxies the list of proxies to choose from,
* never <code>null</code> or empty
* @param target the planned target, never <code>null</code>
* @param request the request to be sent, never <code>null</code>
* @param context the context, or <code>null</code>
*
* @return a proxy type
*/
protected Proxy chooseProxy(List<Proxy> proxies,
HttpHost target,
HttpRequest request,
HttpContext context) {
if ((proxies == null) || proxies.isEmpty()) {
throw new IllegalArgumentException
("Proxy list must not be empty.");
}
Proxy result = null;
// check the list for one we can use
for (int i=0; (result == null) && (i < proxies.size()); i++) {
Proxy p = proxies.get(i);
switch (p.type()) {
case DIRECT:
case HTTP:
result = p;
break;
case SOCKS:
// SOCKS hosts are not handled on the route level.
// The socket may make use of the SOCKS host though.
break;
}
}
if (result == null) {
//@@@ log as warning or info that only a socks proxy is available?
// result can only be null if all proxies are socks proxies
// socks proxies are not handled on the route planning level
result = Proxy.NO_PROXY;
}
return result;
}
}