Java tutorial
/* * ==================================================================== * 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.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.HttpException; import org.apache.http.HttpHost; import org.apache.http.HttpRequest; import org.apache.http.annotation.Immutable; import org.apache.http.conn.SchemePortResolver; import org.apache.http.protocol.HttpContext; /** * {@link org.apache.http.conn.routing.HttpRoutePlanner} implementation * based on {@link ProxySelector}. By default, this class will pick up * the proxy settings of the JVM, either from system properties * or from the browser running the application. * * @since 4.3 */ @Immutable public class SystemDefaultRoutePlanner extends DefaultRoutePlanner { private final ProxySelector proxySelector; public SystemDefaultRoutePlanner(final SchemePortResolver schemePortResolver, final ProxySelector proxySelector) { super(schemePortResolver); this.proxySelector = proxySelector != null ? proxySelector : ProxySelector.getDefault(); } public SystemDefaultRoutePlanner(final ProxySelector proxySelector) { this(null, proxySelector); } @Override protected HttpHost determineProxy(final HttpHost target, final HttpRequest request, final HttpContext context) throws HttpException { final URI targetURI; try { targetURI = new URI(target.toURI()); } catch (final URISyntaxException ex) { throw new HttpException("Cannot convert host to URI: " + target, ex); } final List<Proxy> proxies = this.proxySelector.select(targetURI); final Proxy p = chooseProxy(proxies); 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; } private String getHost(final 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(); } private Proxy chooseProxy(final List<Proxy> proxies) { Proxy result = null; // check the list for one we can use for (int i = 0; (result == null) && (i < proxies.size()); i++) { final 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; } }