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Java example source code file (OperatorConnectProxy.java)

This example source code file (OperatorConnectProxy.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java tags/keywords

basichttpcontext, basichttpparams, basichttprequest, defaultclientconnectionoperator, httpcontext, httphost, httprequest, httpresponse, operatedclientconnection, operatorconnectproxy, options, scheme, schemeregistry, string

The OperatorConnectProxy.java example source code

/*
 * ====================================================================
 * 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.conn;

import org.apache.http.Header;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.conn.ClientConnectionOperator;
import org.apache.http.conn.OperatedClientConnection;
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.ssl.SSLSocketFactory;
import org.apache.http.impl.conn.DefaultClientConnectionOperator;
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.protocol.HttpContext;
import org.apache.http.protocol.BasicHttpContext;

/**
 * How to open a secure connection through a proxy using
 * {@link ClientConnectionOperator ClientConnectionOperator}.
 * This exemplifies the <i>opening of the connection only.
 * The message exchange, both subsequently and for tunnelling,
 * should not be used as a template.
 *
 * @since 4.0
 */
public class OperatorConnectProxy {

    public static void main(String[] args) throws Exception {

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

        // some general setup
        // Register the "http" and "https" protocol schemes, they are
        // required by the default operator to look up socket factories.
        SchemeRegistry supportedSchemes = new SchemeRegistry();
        supportedSchemes.register(new Scheme("http", 
                PlainSocketFactory.getSocketFactory(), 80));
        supportedSchemes.register(new Scheme("https", 
                SSLSocketFactory.getSocketFactory(), 443));

        // Prepare parameters.
        // Since this example doesn't use the full core framework,
        // only few parameters are actually required.
        HttpParams params = new BasicHttpParams();
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setUseExpectContinue(params, false);

        // one operator can be used for many connections
        ClientConnectionOperator scop = new DefaultClientConnectionOperator(supportedSchemes);

        HttpRequest req = new BasicHttpRequest("OPTIONS", "*", HttpVersion.HTTP_1_1);
        // In a real application, request interceptors should be used
        // to add the required headers.
        req.addHeader("Host", target.getHostName());
        
        HttpContext ctx = new BasicHttpContext();

        OperatedClientConnection conn = scop.createConnection();
        try {
            System.out.println("opening connection to " + proxy);
            scop.openConnection(conn, proxy, null, ctx, params);

            // Creates a request to tunnel a connection.
            // For details see RFC 2817, section 5.2
            String authority = target.getHostName() + ":" + target.getPort();
            HttpRequest connect = new BasicHttpRequest("CONNECT", authority, 
                    HttpVersion.HTTP_1_1);
            // In a real application, request interceptors should be used
            // to add the required headers.
            connect.addHeader("Host", authority);

            System.out.println("opening tunnel to " + target);
            conn.sendRequestHeader(connect);
            // there is no request entity
            conn.flush();

            System.out.println("receiving confirmation for tunnel");
            HttpResponse connected = conn.receiveResponseHeader();
            System.out.println("----------------------------------------");
            printResponseHeader(connected);
            System.out.println("----------------------------------------");
            int status = connected.getStatusLine().getStatusCode();
            if ((status < 200) || (status > 299)) {
                System.out.println("unexpected status code " + status);
                System.exit(1);
            }
            System.out.println("receiving response body (ignored)");
            conn.receiveResponseEntity(connected);

            // Now we have a tunnel to the target. As we will be creating a
            // layered TLS/SSL socket immediately afterwards, updating the
            // connection with the new target is optional - but good style.
            // The scheme part of the target is already "https", though the
            // connection is not yet switched to the TLS/SSL protocol.
            conn.update(null, target, false, params);

            System.out.println("layering secure connection");
            scop.updateSecureConnection(conn, target, ctx, params);

            // finally we have the secure connection and can send the request

            System.out.println("sending request");
            conn.sendRequestHeader(req);
            // there is no request entity
            conn.flush();

            System.out.println("receiving response header");
            HttpResponse rsp = conn.receiveResponseHeader();

            System.out.println("----------------------------------------");
            printResponseHeader(rsp);
            System.out.println("----------------------------------------");

        } finally {
            System.out.println("closing connection");
            conn.close();
        }
    }

    private final static void printResponseHeader(HttpResponse rsp) {
        System.out.println(rsp.getStatusLine());
        Header[] headers = rsp.getAllHeaders();
        for (int i=0; i<headers.length; i++) {
            System.out.println(headers[i]);
        }
    }

}

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