clientexecuteproxy.java

来自「用java调用httpclient的方式获取网页内容」· Java 代码 · 共 197 行

/*
 * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/examples/org/apache/http/examples/client/ClientExecuteProxy.java $
 * $Revision: 672425 $
 * $Date: 2008-06-28 00:33:05 +0100 (Sat, 28 Jun 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.examples.client;


import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.params.ConnRoutePNames;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.scheme.SocketFactory;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.util.EntityUtils;



/**
 * How to send a request via proxy using {@link HttpClient HttpClient}.
 *
 * @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
 *
 *
 * <!-- empty lines above to avoid 'svn diff' context problems -->
 * @version $Revision: 672425 $
 *
 * @since 4.0
 */
public class ClientExecuteProxy {

    /**
     * The default parameters.
     * Instantiated in {@link #setup setup}.
     */
    private static HttpParams defaultParameters = null;

    /**
     * The scheme registry.
     * Instantiated in {@link #setup setup}.
     */
    private static SchemeRegistry supportedSchemes;


    /**
     * Main entry point to this example.
     *
     * @param args      ignored
     */
    public final static void main(String[] args)
        throws Exception {

        // make sure to use a proxy that supports CONNECT
        final HttpHost target =
            new HttpHost("issues.apache.org", 443, "https");
        final HttpHost proxy =
            new HttpHost("127.0.0.1", 8666, "http");

        setup(); // some general setup

        HttpClient client = createHttpClient();

        client.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

        HttpRequest req = createRequest();

        System.out.println("executing request to " + target + " via " + proxy);
        HttpEntity entity = null;
        try {
            HttpResponse rsp = client.execute(target, req);
            entity = rsp.getEntity();

            System.out.println("----------------------------------------");
            System.out.println(rsp.getStatusLine());
            Header[] headers = rsp.getAllHeaders();
            for (int i=0; i<headers.length; i++) {
                System.out.println(headers[i]);
            }
            System.out.println("----------------------------------------");

            if (rsp.getEntity() != null) {
                System.out.println(EntityUtils.toString(rsp.getEntity()));
            }

        } finally {
            // If we could be sure that the stream of the entity has been
            // closed, we wouldn't need this code to release the connection.
            // However, EntityUtils.toString(...) can throw an exception.

            // if there is no entity, the connection is already released
            if (entity != null)
                entity.consumeContent(); // release connection gracefully
        }
    } // main


    private final static HttpClient createHttpClient() {

        ClientConnectionManager ccm =
            new ThreadSafeClientConnManager(getParams(), supportedSchemes);
        //  new SingleClientConnManager(getParams(), supportedSchemes);

        DefaultHttpClient dhc =
            new DefaultHttpClient(ccm, getParams());

        return dhc;
    }


    /**
     * Performs general setup.
     * This should be called only once.
     */
    private final static void setup() {

        supportedSchemes = new SchemeRegistry();

        // Register the "http" and "https" protocol schemes, they are
        // required by the default operator to look up socket factories.
        SocketFactory sf = PlainSocketFactory.getSocketFactory();
        supportedSchemes.register(new Scheme("http", sf, 80));
        sf = SSLSocketFactory.getSocketFactory();
        supportedSchemes.register(new Scheme("https", sf, 80));

        // prepare parameters
        HttpParams params = new BasicHttpParams();
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setContentCharset(params, "UTF-8");
        HttpProtocolParams.setUseExpectContinue(params, true);
        defaultParameters = params;

    } // setup


    private final static HttpParams getParams() {
        return defaultParameters;
    }


    /**
     * Creates a request to execute in this example.
     *
     * @return  a request without an entity
     */
    private final static HttpRequest createRequest() {

        HttpRequest req = new BasicHttpRequest
            ("GET", "/", HttpVersion.HTTP_1_1);
          //("OPTIONS", "*", HttpVersion.HTTP_1_1);

        return req;
    }


} // class ClientExecuteProxy