HttpCore组件案例程序(Java描述) (Http Components-- HttpCore Examples)

一、基本概念

      HttpCore是一套实现了HTTP协议最基础方面的组件，尽管HTTP协议在使用最小占用来开发全功能的客户端和服务器的HTTP服务是足够的。
      HttpCore有如下的范围和目标(@Author: 南磊)：

1. HttpCore范围

  ■构建客户端/代理/服务器端HTTP服务一致的API
  ■构建同步和异步HTTP服务一致的API
  ■基于阻塞（经典的）和非阻塞（NIO）I/O模型的一套低等级组件

2. HttpCore目标

  ■实现最基本的HTTP传输方面
  ■良好性能和清晰度&表现力之间的平衡
  ■小的（预测）内存占用
  ■自我包含的类库（没有超越JRE的额外依赖）

3.  什么是HttpCore不能做的

  ■HttpClient的替代
  ■Servlet容器或Servlet API竞争对手的替代

二、源代码详解

1.基本的Http获取程序（基于同步或加锁的I/O模型）

/*
 * ====================================================================
 * 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;

import java.net.Socket;

import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.DefaultHttpClientConnection;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestExecutor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.util.EntityUtils;

/**
 * Elemental example for executing multiple GET requests sequentially.
 * <p>
 * Please note the purpose of this application is demonstrate the usage of HttpCore APIs.
 * It is NOT intended to demonstrate the most efficient way of building an HTTP client.
 */
public class ElementalHttpGet {

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

        HttpParams params = new SyncBasicHttpParams();
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setContentCharset(params, "UTF-8");
        HttpProtocolParams.setUserAgent(params, "HttpComponents/1.1");
        HttpProtocolParams.setUseExpectContinue(params, true);

        HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] {
                // Required protocol interceptors
                new RequestContent(),
                new RequestTargetHost(),
                // Recommended protocol interceptors
                new RequestConnControl(),
                new RequestUserAgent(),
                new RequestExpectContinue()});

        HttpRequestExecutor httpexecutor = new HttpRequestExecutor();

        HttpContext context = new BasicHttpContext(null);
        HttpHost host = new HttpHost("localhost", 8080);

        DefaultHttpClientConnection conn = new DefaultHttpClientConnection();
        ConnectionReuseStrategy connStrategy = new DefaultConnectionReuseStrategy();

        context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
        context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, host);

        try {

            String[] targets = {
                    "/",
                    "/servlets-examples/servlet/RequestInfoExample",
                    "/somewhere%20in%20pampa"};

            for (int i = 0; i < targets.length; i++) {
                if (!conn.isOpen()) {
                    Socket socket = new Socket(host.getHostName(), host.getPort());
                    conn.bind(socket, params);
                }
                BasicHttpRequest request = new BasicHttpRequest("GET", targets[i]);
                System.out.println(">> Request URI: " + request.getRequestLine().getUri());

                request.setParams(params);
                httpexecutor.preProcess(request, httpproc, context);
                HttpResponse response = httpexecutor.execute(request, conn, context);
                response.setParams(params);
                httpexecutor.postProcess(response, httpproc, context);

                System.out.println("<< Response: " + response.getStatusLine());
                System.out.println(EntityUtils.toString(response.getEntity()));
                System.out.println("==============");
                if (!connStrategy.keepAlive(response, context)) {
                    conn.close();
                } else {
                    System.out.println("Connection kept alive...");
                }
            }
        } finally {
            conn.close();
        }
    }

}

2.基本的Http发送程序（基于同步或加锁的I/O模型）

/*
 * ====================================================================
 * 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;

import java.io.ByteArrayInputStream;
import java.net.Socket;

import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.entity.InputStreamEntity;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.DefaultHttpClientConnection;
import org.apache.http.message.BasicHttpEntityEnclosingRequest;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestExecutor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.util.EntityUtils;

/**
 * Elemental example for executing multiple POST requests sequentially.
 * <p>
 * Please note the purpose of this application is demonstrate the usage of HttpCore APIs.
 * It is NOT intended to demonstrate the most efficient way of building an HTTP client.
 */
public class ElementalHttpPost {

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

        HttpParams params = new SyncBasicHttpParams();
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setContentCharset(params, "UTF-8");
        HttpProtocolParams.setUserAgent(params, "Test/1.1");
        HttpProtocolParams.setUseExpectContinue(params, true);

        HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] {
                // Required protocol interceptors
                new RequestContent(),
                new RequestTargetHost(),
                // Recommended protocol interceptors
                new RequestConnControl(),
                new RequestUserAgent(),
                new RequestExpectContinue()});

        HttpRequestExecutor httpexecutor = new HttpRequestExecutor();

        HttpContext context = new BasicHttpContext(null);

        HttpHost host = new HttpHost("localhost", 8080);

        DefaultHttpClientConnection conn = new DefaultHttpClientConnection();
        ConnectionReuseStrategy connStrategy = new DefaultConnectionReuseStrategy();

        context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
        context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, host);

        try {

            HttpEntity[] requestBodies = {
                    new StringEntity(
                            "This is the first test request", "UTF-8"),
                    new ByteArrayEntity(
                            "This is the second test request".getBytes("UTF-8")),
                    new InputStreamEntity(
                            new ByteArrayInputStream(
                                    "This is the third test request (will be chunked)"
                                    .getBytes("UTF-8")), -1)
            };

            for (int i = 0; i < requestBodies.length; i++) {
                if (!conn.isOpen()) {
                    Socket socket = new Socket(host.getHostName(), host.getPort());
                    conn.bind(socket, params);
                }
                BasicHttpEntityEnclosingRequest request = new BasicHttpEntityEnclosingRequest("POST",
                        "/servlets-examples/servlet/RequestInfoExample");
                request.setEntity(requestBodies[i]);
                System.out.println(">> Request URI: " + request.getRequestLine().getUri());

                request.setParams(params);
                httpexecutor.preProcess(request, httpproc, context);
                HttpResponse response = httpexecutor.execute(request, conn, context);
                response.setParams(params);
                httpexecutor.postProcess(response, httpproc, context);

                System.out.println("<< Response: " + response.getStatusLine());
                System.out.println(EntityUtils.toString(response.getEntity()));
                System.out.println("==============");
                if (!connStrategy.keepAlive(response, context)) {
                    conn.close();
                } else {
                    System.out.println("Connection kept alive...");
                }
            }
        } finally {
            conn.close();
        }
    }

}

3.基本的Http服务器程序（基于同步或加锁的I/O模型）

/*
 * ====================================================================
 * 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;

import java.io.File;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URLDecoder;
import java.nio.charset.Charset;
import java.util.Locale;

import org.apache.http.ConnectionClosedException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.HttpServerConnection;
import org.apache.http.HttpStatus;
import org.apache.http.MethodNotSupportedException;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.FileEntity;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.DefaultHttpResponseFactory;
import org.apache.http.impl.DefaultHttpServerConnection;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.HttpParams;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestHandler;
import org.apache.http.protocol.HttpRequestHandlerRegistry;
import org.apache.http.protocol.HttpService;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.ResponseConnControl;
import org.apache.http.protocol.ResponseContent;
import org.apache.http.protocol.ResponseDate;
import org.apache.http.protocol.ResponseServer;
import org.apache.http.util.EntityUtils;

/**
 * Basic, yet fully functional and spec compliant, HTTP/1.1 file server.
 * <p>
 * Please note the purpose of this application is demonstrate the usage of HttpCore APIs.
 * It is NOT intended to demonstrate the most efficient way of building an HTTP file server.
 *
 *
 */
public class ElementalHttpServer {

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.err.println("Please specify document root directory");
            System.exit(1);
        }
        Thread t = new RequestListenerThread(8080, args[0]);
        t.setDaemon(false);
        t.start();
    }

    static class HttpFileHandler implements HttpRequestHandler  {

        private final String docRoot;

        public HttpFileHandler(final String docRoot) {
            super();
            this.docRoot = docRoot;
        }

        public void handle(
                final HttpRequest request,
                final HttpResponse response,
                final HttpContext context) throws HttpException, IOException {

            String method = request.getRequestLine().getMethod().toUpperCase(Locale.ENGLISH);
            if (!method.equals("GET") && !method.equals("HEAD") && !method.equals("POST")) {
                throw new MethodNotSupportedException(method + " method not supported");
            }
            String target = request.getRequestLine().getUri();

            if (request instanceof HttpEntityEnclosingRequest) {
                HttpEntity entity = ((HttpEntityEnclosingRequest) request).getEntity();
                byte[] entityContent = EntityUtils.toByteArray(entity);
                System.out.println("Incoming entity content (bytes): " + entityContent.length);
            }

            final File file = new File(this.docRoot, URLDecoder.decode(target, "UTF-8"));
            if (!file.exists()) {

                response.setStatusCode(HttpStatus.SC_NOT_FOUND);
                StringEntity entity = new StringEntity(
                        "<html><body><h1>File" + file.getPath() +
                        " not found</h1></body></html>",
                        ContentType.create("text/html", "UTF-8"));
                response.setEntity(entity);
                System.out.println("File " + file.getPath() + " not found");

            } else if (!file.canRead() || file.isDirectory()) {

                response.setStatusCode(HttpStatus.SC_FORBIDDEN);
                StringEntity entity = new StringEntity(
                        "<html><body><h1>Access denied</h1></body></html>",
                        ContentType.create("text/html", "UTF-8"));
                response.setEntity(entity);
                System.out.println("Cannot read file " + file.getPath());

            } else {

                response.setStatusCode(HttpStatus.SC_OK);
                FileEntity body = new FileEntity(file, ContentType.create("text/html", (Charset) null));
                response.setEntity(body);
                System.out.println("Serving file " + file.getPath());
            }
        }

    }

    static class RequestListenerThread extends Thread {

        private final ServerSocket serversocket;
        private final HttpParams params;
        private final HttpService httpService;

        public RequestListenerThread(int port, final String docroot) throws IOException {
            this.serversocket = new ServerSocket(port);
            this.params = new SyncBasicHttpParams();
            this.params
                .setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 5000)
                .setIntParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 8 * 1024)
                .setBooleanParameter(CoreConnectionPNames.STALE_CONNECTION_CHECK, false)
                .setBooleanParameter(CoreConnectionPNames.TCP_NODELAY, true)
                .setParameter(CoreProtocolPNames.ORIGIN_SERVER, "HttpComponents/1.1");

            // Set up the HTTP protocol processor
            HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpResponseInterceptor[] {
                    new ResponseDate(),
                    new ResponseServer(),
                    new ResponseContent(),
                    new ResponseConnControl()
            });

            // Set up request handlers
            HttpRequestHandlerRegistry reqistry = new HttpRequestHandlerRegistry();
            reqistry.register("*", new HttpFileHandler(docroot));

            // Set up the HTTP service
            this.httpService = new HttpService(
                    httpproc,
                    new DefaultConnectionReuseStrategy(),
                    new DefaultHttpResponseFactory(),
                    reqistry,
                    this.params);
        }

        @Override
        public void run() {
            System.out.println("Listening on port " + this.serversocket.getLocalPort());
            while (!Thread.interrupted()) {
                try {
                    // Set up HTTP connection
                    Socket socket = this.serversocket.accept();
                    DefaultHttpServerConnection conn = new DefaultHttpServerConnection();
                    System.out.println("Incoming connection from " + socket.getInetAddress());
                    conn.bind(socket, this.params);

                    // Start worker thread
                    Thread t = new WorkerThread(this.httpService, conn);
                    t.setDaemon(true);
                    t.start();
                } catch (InterruptedIOException ex) {
                    break;
                } catch (IOException e) {
                    System.err.println("I/O error initialising connection thread: "
                            + e.getMessage());
                    break;
                }
            }
        }
    }

    static class WorkerThread extends Thread {

        private final HttpService httpservice;
        private final HttpServerConnection conn;

        public WorkerThread(
                final HttpService httpservice,
                final HttpServerConnection conn) {
            super();
            this.httpservice = httpservice;
            this.conn = conn;
        }

        @Override
        public void run() {
            System.out.println("New connection thread");
            HttpContext context = new BasicHttpContext(null);
            try {
                while (!Thread.interrupted() && this.conn.isOpen()) {
                    this.httpservice.handleRequest(this.conn, context);
                }
            } catch (ConnectionClosedException ex) {
                System.err.println("Client closed connection");
            } catch (IOException ex) {
                System.err.println("I/O error: " + ex.getMessage());
            } catch (HttpException ex) {
                System.err.println("Unrecoverable HTTP protocol violation: " + ex.getMessage());
            } finally {
                try {
                    this.conn.shutdown();
                } catch (IOException ignore) {}
            }
        }

    }

}

4.异步的Http获取程序（基于非阻塞I/O模型：NIO框架）

      HttpCore NIO是基于由Doug Lea定义描述的反应器模式的。I/O反应器的目标是反应I/O事件然后分发事件通知到独立的I/O会话中。I/O反应器模式的主要思想是从每次连接模型 摆脱一个由经典阻塞I/O模型强加的线程。IOReactor接口代表了反应器模式抽象的对象实现。在其内部，IOReactor实现封装了了NIO java.nio.channels.Selector的功能。

      I/O反应器通常使用一小部分分发线程（通常是一个）来分发I/O事件通知到一个很大数量（通常是好几千）的I/O会话或连接。通常建议每个CPU核心只有一个分发线程。

II.I/O分发器

      IOReactor实现使用了IOEventDispatch接口来通知事件客户端为特定的会话挂起。IOEventDispatch的所有方法在I/O 反应器的分发线程上执行。因此，在事件方法上的处理不会阻塞分发线程很长时间，这一点是很重要的，而且I/O反应器也不可能对其它事件做出反应。

      由IOEventDispatch接口定义的通用I/O事件：

• connected：当一个新的会话创建时触发。
• inputReady：当新的会话等待输入时触发。
• outputReady：当会话准备输出时触发。
• timeout：当会话超时时触发。
• disconnected：当会话终止时触发。

/*
 * ====================================================================
 * 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.nio;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.concurrent.CountDownLatch;

import org.apache.http.HttpHost;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.nio.DefaultHttpClientIODispatch;
import org.apache.http.impl.nio.pool.BasicNIOConnPool;
import org.apache.http.impl.nio.reactor.DefaultConnectingIOReactor;
import org.apache.http.impl.nio.reactor.IOReactorConfig;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.nio.protocol.BasicAsyncRequestProducer;
import org.apache.http.nio.protocol.BasicAsyncResponseConsumer;
import org.apache.http.nio.protocol.HttpAsyncRequestExecutor;
import org.apache.http.nio.protocol.HttpAsyncRequester;
import org.apache.http.nio.reactor.ConnectingIOReactor;
import org.apache.http.nio.reactor.IOEventDispatch;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;

/**
 * Asynchronous HTTP/1.1 client.
 */
public class NHttpClient {

    public static void main(String[] args) throws Exception {
        // HTTP parameters for the client
        HttpParams params = new SyncBasicHttpParams();
        params
            .setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 3000)
            .setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, 3000)
            .setIntParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 8 * 1024)
            .setBooleanParameter(CoreConnectionPNames.TCP_NODELAY, true)
            .setParameter(CoreProtocolPNames.USER_AGENT, "Test/1.1");
        // Create HTTP protocol processing chain
        HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] {
                // Use standard client-side protocol interceptors
                new RequestContent(),
                new RequestTargetHost(),
                new RequestConnControl(),
                new RequestUserAgent(),
                new RequestExpectContinue()});
        // Create client-side HTTP protocol handler
        HttpAsyncRequestExecutor protocolHandler = new HttpAsyncRequestExecutor();
        // Create client-side I/O event dispatch
        final IOEventDispatch ioEventDispatch = new DefaultHttpClientIODispatch(protocolHandler, params);
        // Create client-side I/O reactor
        IOReactorConfig config = new IOReactorConfig();
        config.setIoThreadCount(1);
        final ConnectingIOReactor ioReactor = new DefaultConnectingIOReactor(config);
        // Create HTTP connection pool
        BasicNIOConnPool pool = new BasicNIOConnPool(ioReactor, params);
        // Limit total number of connections to just two
        pool.setDefaultMaxPerRoute(2);
        pool.setMaxTotal(2);
        // Run the I/O reactor in a separate thread
        Thread t = new Thread(new Runnable() {

            public void run() {
                try {
                    // Ready to go!
                    ioReactor.execute(ioEventDispatch);
                } catch (InterruptedIOException ex) {
                    System.err.println("Interrupted");
                } catch (IOException e) {
                    System.err.println("I/O error: " + e.getMessage());
                }
                System.out.println("Shutdown");
            }

        });
        // Start the client thread
        t.start();
        // Create HTTP requester
        HttpAsyncRequester requester = new HttpAsyncRequester(
                httpproc, new DefaultConnectionReuseStrategy(), params);
        // Execute HTTP GETs to the following hosts and
        HttpHost[] targets = new HttpHost[] {
                new HttpHost("www.apache.org", 80, "http"),
                new HttpHost("www.verisign.com", 443, "https"),
                new HttpHost("www.google.com", 80, "http")
        };
        final CountDownLatch latch = new CountDownLatch(targets.length);
        for (final HttpHost target: targets) {
            BasicHttpRequest request = new BasicHttpRequest("GET", "/");
            requester.execute(
                    new BasicAsyncRequestProducer(target, request),
                    new BasicAsyncResponseConsumer(),
                    pool,
                    new BasicHttpContext(),
                    // Handle HTTP response from a callback
                    new FutureCallback<HttpResponse>() {

                public void completed(final HttpResponse response) {
                    latch.countDown();
                    System.out.println(target + "->" + response.getStatusLine());
                }

                public void failed(final Exception ex) {
                    latch.countDown();
                    System.out.println(target + "->" + ex);
                }

                public void cancelled() {
                    latch.countDown();
                    System.out.println(target + " cancelled");
                }

            });
        }
        latch.await();
        System.out.println("Shutting down I/O reactor");
        ioReactor.shutdown();
        System.out.println("Done");
    }

}

5.异步的Http服务器程序（基于非阻塞I/O模型：NIO框架）

This example demonstrates the use of HttpCore NIO to build an asynchronous (non-blocking) HTTP server capable of direct channel (zero copy) data transfer.

/*
 * ====================================================================
 * 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.nio;

import java.io.File;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.InetSocketAddress;
import java.net.URL;
import java.net.URLDecoder;
import java.security.KeyStore;
import java.util.Locale;

import javax.net.ssl.KeyManager;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;

import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.HttpStatus;
import org.apache.http.MethodNotSupportedException;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.nio.DefaultNHttpServerConnection;
import org.apache.http.impl.nio.DefaultNHttpServerConnectionFactory;
import org.apache.http.impl.nio.DefaultHttpServerIODispatch;
import org.apache.http.impl.nio.SSLNHttpServerConnectionFactory;
import org.apache.http.impl.nio.reactor.DefaultListeningIOReactor;
import org.apache.http.nio.NHttpConnection;
import org.apache.http.nio.NHttpConnectionFactory;
import org.apache.http.nio.NHttpServerConnection;
import org.apache.http.nio.entity.NFileEntity;
import org.apache.http.nio.entity.NStringEntity;
import org.apache.http.nio.protocol.BasicAsyncRequestConsumer;
import org.apache.http.nio.protocol.BasicAsyncResponseProducer;
import org.apache.http.nio.protocol.HttpAsyncRequestConsumer;
import org.apache.http.nio.protocol.HttpAsyncRequestHandler;
import org.apache.http.nio.protocol.HttpAsyncRequestHandlerRegistry;
import org.apache.http.nio.protocol.HttpAsyncExchange;
import org.apache.http.nio.protocol.HttpAsyncService;
import org.apache.http.nio.reactor.IOEventDispatch;
import org.apache.http.nio.reactor.ListeningIOReactor;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.ResponseConnControl;
import org.apache.http.protocol.ResponseContent;
import org.apache.http.protocol.ResponseDate;
import org.apache.http.protocol.ResponseServer;

/**
 * HTTP/1.1 file server based on the non-blocking I/O model and capable of direct channel
 * (zero copy) data transfer.
 */
public class NHttpServer {

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.err.println("Please specify document root directory");
            System.exit(1);
        }
        // Document root directory
        File docRoot = new File(args[0]);
        int port = 8080;
        if (args.length >= 2) {
            port = Integer.parseInt(args[1]);
        }
        // HTTP parameters for the server
        HttpParams params = new SyncBasicHttpParams();
        params
            .setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 5000)
            .setIntParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 8 * 1024)
            .setBooleanParameter(CoreConnectionPNames.TCP_NODELAY, true)
            .setParameter(CoreProtocolPNames.ORIGIN_SERVER, "HttpTest/1.1");
        // Create HTTP protocol processing chain
        HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpResponseInterceptor[] {
                // Use standard server-side protocol interceptors
                new ResponseDate(),
                new ResponseServer(),
                new ResponseContent(),
                new ResponseConnControl()
        });
        // Create request handler registry
        HttpAsyncRequestHandlerRegistry reqistry = new HttpAsyncRequestHandlerRegistry();
        // Register the default handler for all URIs
        reqistry.register("*", new HttpFileHandler(docRoot));
        // Create server-side HTTP protocol handler
        HttpAsyncService protocolHandler = new HttpAsyncService(
                httpproc, new DefaultConnectionReuseStrategy(), reqistry, params) {

            @Override
            public void connected(final NHttpServerConnection conn) {
                System.out.println(conn + ": connection open");
                super.connected(conn);
            }

            @Override
            public void closed(final NHttpServerConnection conn) {
                System.out.println(conn + ": connection closed");
                super.closed(conn);
            }

        };
        // Create HTTP connection factory
        NHttpConnectionFactory<DefaultNHttpServerConnection> connFactory;
        if (port == 8443) {
            // Initialize SSL context
            ClassLoader cl = NHttpServer.class.getClassLoader();
            URL url = cl.getResource("my.keystore");
            if (url == null) {
                System.out.println("Keystore not found");
                System.exit(1);
            }
            KeyStore keystore  = KeyStore.getInstance("jks");
            keystore.load(url.openStream(), "secret".toCharArray());
            KeyManagerFactory kmfactory = KeyManagerFactory.getInstance(
                    KeyManagerFactory.getDefaultAlgorithm());
            kmfactory.init(keystore, "secret".toCharArray());
            KeyManager[] keymanagers = kmfactory.getKeyManagers();
            SSLContext sslcontext = SSLContext.getInstance("TLS");
            sslcontext.init(keymanagers, null, null);
            connFactory = new SSLNHttpServerConnectionFactory(sslcontext, null, params);
        } else {
            connFactory = new DefaultNHttpServerConnectionFactory(params);
        }
        // Create server-side I/O event dispatch
        IOEventDispatch ioEventDispatch = new DefaultHttpServerIODispatch(protocolHandler, connFactory);
        // Create server-side I/O reactor
        ListeningIOReactor ioReactor = new DefaultListeningIOReactor();
        try {
            // Listen of the given port
            ioReactor.listen(new InetSocketAddress(port));
            // Ready to go!
            ioReactor.execute(ioEventDispatch);
        } catch (InterruptedIOException ex) {
            System.err.println("Interrupted");
        } catch (IOException e) {
            System.err.println("I/O error: " + e.getMessage());
        }
        System.out.println("Shutdown");
    }

    static class HttpFileHandler implements HttpAsyncRequestHandler<HttpRequest> {

        private final File docRoot;

        public HttpFileHandler(final File docRoot) {
            super();
            this.docRoot = docRoot;
        }

        public HttpAsyncRequestConsumer<HttpRequest> processRequest(
                final HttpRequest request,
                final HttpContext context) {
            // Buffer request content in memory for simplicity
            return new BasicAsyncRequestConsumer();
        }

        public void handle(
                final HttpRequest request,
                final HttpAsyncExchange httpexchange,
                final HttpContext context) throws HttpException, IOException {
            HttpResponse response = httpexchange.getResponse();
            handleInternal(request, response, context);
            httpexchange.submitResponse(new BasicAsyncResponseProducer(response));
        }

        private void handleInternal(
                final HttpRequest request,
                final HttpResponse response,
                final HttpContext context) throws HttpException, IOException {

            String method = request.getRequestLine().getMethod().toUpperCase(Locale.ENGLISH);
            if (!method.equals("GET") && !method.equals("HEAD") && !method.equals("POST")) {
                throw new MethodNotSupportedException(method + " method not supported");
            }

            String target = request.getRequestLine().getUri();
            final File file = new File(this.docRoot, URLDecoder.decode(target, "UTF-8"));
            if (!file.exists()) {

                response.setStatusCode(HttpStatus.SC_NOT_FOUND);
                NStringEntity entity = new NStringEntity(
                        "<html><body><h1>File" + file.getPath() +
                        " not found</h1></body></html>",
                        ContentType.create("text/html", "UTF-8"));
                response.setEntity(entity);
                System.out.println("File " + file.getPath() + " not found");

            } else if (!file.canRead() || file.isDirectory()) {

                response.setStatusCode(HttpStatus.SC_FORBIDDEN);
                NStringEntity entity = new NStringEntity(
                        "<html><body><h1>Access denied</h1></body></html>",
                        ContentType.create("text/html", "UTF-8"));
                response.setEntity(entity);
                System.out.println("Cannot read file " + file.getPath());

            } else {
                NHttpConnection conn = (NHttpConnection) context.getAttribute(
                        ExecutionContext.HTTP_CONNECTION);
                response.setStatusCode(HttpStatus.SC_OK);
                NFileEntity body = new NFileEntity(file, ContentType.create("text/html"));
                response.setEntity(body);
                System.out.println(conn + ": serving file " + file.getPath());
            }
        }

    }

}

6.异步的Http逆向代理程序（基于非阻塞I/O模型：NIO框架）

This example demonstrates how HttpCore NIO can be used to build an asynchronous, fully streaming reverse HTTP proxy.

/*
 * ====================================================================
 * 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.nio;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.InetSocketAddress;
import java.net.URI;
import java.nio.ByteBuffer;
import java.util.Locale;
import java.util.concurrent.atomic.AtomicLong;

import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.EnglishReasonPhraseCatalog;
import org.apache.http.impl.nio.DefaultHttpClientIODispatch;
import org.apache.http.impl.nio.DefaultHttpServerIODispatch;
import org.apache.http.impl.nio.pool.BasicNIOConnPool;
import org.apache.http.impl.nio.pool.BasicNIOPoolEntry;
import org.apache.http.impl.nio.reactor.DefaultConnectingIOReactor;
import org.apache.http.impl.nio.reactor.DefaultListeningIOReactor;
import org.apache.http.impl.nio.reactor.IOReactorConfig;
import org.apache.http.message.BasicHttpEntityEnclosingRequest;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.message.BasicHttpResponse;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.NHttpClientConnection;
import org.apache.http.nio.NHttpConnection;
import org.apache.http.nio.NHttpServerConnection;
import org.apache.http.nio.entity.NStringEntity;
import org.apache.http.nio.pool.NIOConnFactory;
import org.apache.http.nio.protocol.BasicAsyncResponseProducer;
import org.apache.http.nio.protocol.HttpAsyncRequestExecutor;
import org.apache.http.nio.protocol.HttpAsyncRequestConsumer;
import org.apache.http.nio.protocol.HttpAsyncRequester;
import org.apache.http.nio.protocol.HttpAsyncRequestHandler;
import org.apache.http.nio.protocol.HttpAsyncRequestHandlerRegistry;
import org.apache.http.nio.protocol.HttpAsyncRequestHandlerResolver;
import org.apache.http.nio.protocol.HttpAsyncRequestProducer;
import org.apache.http.nio.protocol.HttpAsyncResponseConsumer;
import org.apache.http.nio.protocol.HttpAsyncResponseProducer;
import org.apache.http.nio.protocol.HttpAsyncExchange;
import org.apache.http.nio.protocol.HttpAsyncService;
import org.apache.http.nio.reactor.ConnectingIOReactor;
import org.apache.http.nio.reactor.IOEventDispatch;
import org.apache.http.nio.reactor.ListeningIOReactor;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.pool.PoolStats;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.protocol.ResponseConnControl;
import org.apache.http.protocol.ResponseContent;
import org.apache.http.protocol.ResponseDate;
import org.apache.http.protocol.ResponseServer;

/**
 * Asynchronous, fully streaming HTTP/1.1 reverse proxy.
 */
public class NHttpReverseProxy {

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.out.println("Usage: NHttpReverseProxy <hostname> [port]");
            System.exit(1);
        }
        URI uri = new URI(args[0]);
        int port = 8080;
        if (args.length > 1) {
            port = Integer.parseInt(args[1]);
        }

        // Target host
        HttpHost targetHost = new HttpHost(
                uri.getHost(),
                uri.getPort() > 0 ? uri.getPort() : 80,
                uri.getScheme() != null ? uri.getScheme() : "http");

        System.out.println("Reverse proxy to " + targetHost);

        HttpParams params = new SyncBasicHttpParams();
        params
            .setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 30000)
            .setIntParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 8 * 1024)
            .setBooleanParameter(CoreConnectionPNames.TCP_NODELAY, true)
            .setParameter(CoreProtocolPNames.ORIGIN_SERVER, "Test/1.1")
            .setParameter(CoreProtocolPNames.USER_AGENT, "Test/1.1");

        IOReactorConfig config = new IOReactorConfig();
        config.setIoThreadCount(1);
        final ConnectingIOReactor connectingIOReactor = new DefaultConnectingIOReactor(config);
        final ListeningIOReactor listeningIOReactor = new DefaultListeningIOReactor(config);

        // Set up HTTP protocol processor for incoming connections
        HttpProcessor inhttpproc = new ImmutableHttpProcessor(
                new HttpResponseInterceptor[] {
                        new ResponseDate(),
                        new ResponseServer(),
                        new ResponseContent(),
                        new ResponseConnControl()
         });

        // Set up HTTP protocol processor for outgoing connections
        HttpProcessor outhttpproc = new ImmutableHttpProcessor(
                new HttpRequestInterceptor[] {
                        new RequestContent(),
                        new RequestTargetHost(),
                        new RequestConnControl(),
                        new RequestUserAgent(),
                        new RequestExpectContinue()
        });

        ProxyClientProtocolHandler clientHandler = new ProxyClientProtocolHandler();
        HttpAsyncRequester executor = new HttpAsyncRequester(
                outhttpproc, new ProxyOutgoingConnectionReuseStrategy(), params);

        ProxyConnPool connPool = new ProxyConnPool(connectingIOReactor, params);
        connPool.setMaxTotal(100);
        connPool.setDefaultMaxPerRoute(20);

        HttpAsyncRequestHandlerRegistry handlerRegistry = new HttpAsyncRequestHandlerRegistry();
        handlerRegistry.register("*", new ProxyRequestHandler(targetHost, executor, connPool));

        ProxyServiceHandler serviceHandler = new ProxyServiceHandler(
                inhttpproc, new ProxyIncomingConnectionReuseStrategy(), handlerRegistry, params);

        final IOEventDispatch connectingEventDispatch = new DefaultHttpClientIODispatch(
                clientHandler, params);

        final IOEventDispatch listeningEventDispatch = new DefaultHttpServerIODispatch(
                serviceHandler, params);

        Thread t = new Thread(new Runnable() {

            public void run() {
                try {
                    connectingIOReactor.execute(connectingEventDispatch);
                } catch (InterruptedIOException ex) {
                    System.err.println("Interrupted");
                } catch (IOException ex) {
                    ex.printStackTrace();
                } finally {
                    try {
                        listeningIOReactor.shutdown();
                    } catch (IOException ex2) {
                        ex2.printStackTrace();
                    }
                }
            }

        });
        t.start();
        try {
            listeningIOReactor.listen(new InetSocketAddress(port));
            listeningIOReactor.execute(listeningEventDispatch);
        } catch (InterruptedIOException ex) {
            System.err.println("Interrupted");
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            try {
                connectingIOReactor.shutdown();
            } catch (IOException ex2) {
                ex2.printStackTrace();
            }
        }
    }

    static class ProxyHttpExchange {

        private final ByteBuffer inBuffer;
        private final ByteBuffer outBuffer;

        private volatile String id;
        private volatile HttpHost target;
        private volatile HttpAsyncExchange responseTrigger;
        private volatile IOControl originIOControl;
        private volatile IOControl clientIOControl;
        private volatile HttpRequest request;
        private volatile boolean requestReceived;
        private volatile HttpResponse response;
        private volatile boolean responseReceived;
        private volatile Exception ex;

        public ProxyHttpExchange() {
            super();
            this.inBuffer = ByteBuffer.allocateDirect(10240);
            this.outBuffer = ByteBuffer.allocateDirect(10240);
        }

        public ByteBuffer getInBuffer() {
            return this.inBuffer;
        }

        public ByteBuffer getOutBuffer() {
            return this.outBuffer;
        }

        public String getId() {
            return this.id;
        }

        public void setId(final String id) {
            this.id = id;
        }

        public HttpHost getTarget() {
            return this.target;
        }

        public void setTarget(final HttpHost target) {
            this.target = target;
        }

        public HttpRequest getRequest() {
            return this.request;
        }

        public void setRequest(final HttpRequest request) {
            this.request = request;
        }

        public HttpResponse getResponse() {
            return this.response;
        }

        public void setResponse(final HttpResponse response) {
            this.response = response;
        }

        public HttpAsyncExchange getResponseTrigger() {
            return this.responseTrigger;
        }

        public void setResponseTrigger(final HttpAsyncExchange responseTrigger) {
            this.responseTrigger = responseTrigger;
        }

        public IOControl getClientIOControl() {
            return this.clientIOControl;
        }

        public void setClientIOControl(final IOControl clientIOControl) {
            this.clientIOControl = clientIOControl;
        }

        public IOControl getOriginIOControl() {
            return this.originIOControl;
        }

        public void setOriginIOControl(final IOControl originIOControl) {
            this.originIOControl = originIOControl;
        }

        public boolean isRequestReceived() {
            return this.requestReceived;
        }

        public void setRequestReceived() {
            this.requestReceived = true;
        }

        public boolean isResponseReceived() {
            return this.responseReceived;
        }

        public void setResponseReceived() {
            this.responseReceived = true;
        }

        public Exception getException() {
            return this.ex;
        }

        public void setException(final Exception ex) {
            this.ex = ex;
        }

        public void reset() {
            this.inBuffer.clear();
            this.outBuffer.clear();
            this.target = null;
            this.id = null;
            this.responseTrigger = null;
            this.clientIOControl = null;
            this.originIOControl = null;
            this.request = null;
            this.requestReceived = false;
            this.response = null;
            this.responseReceived = false;
            this.ex = null;
        }

    }

    static class ProxyRequestHandler implements HttpAsyncRequestHandler<ProxyHttpExchange> {

        private final HttpHost target;
        private final HttpAsyncRequester executor;
        private final BasicNIOConnPool connPool;
        private final AtomicLong counter;

        public ProxyRequestHandler(
                final HttpHost target,
                final HttpAsyncRequester executor,
                final BasicNIOConnPool connPool) {
            super();
            this.target = target;
            this.executor = executor;
            this.connPool = connPool;
            this.counter = new AtomicLong(1);
        }

        public HttpAsyncRequestConsumer<ProxyHttpExchange> processRequest(
                final HttpRequest request,
                final HttpContext context) {
            ProxyHttpExchange httpExchange = (ProxyHttpExchange) context.getAttribute("http-exchange");
            if (httpExchange == null) {
                httpExchange = new ProxyHttpExchange();
                context.setAttribute("http-exchange", httpExchange);
            }
            synchronized (httpExchange) {
                httpExchange.reset();
                String id = String.format("%08X", this.counter.getAndIncrement());
                httpExchange.setId(id);
                httpExchange.setTarget(this.target);
                return new ProxyRequestConsumer(httpExchange, this.executor, this.connPool);
            }
        }

        public void handle(
                final ProxyHttpExchange httpExchange,
                final HttpAsyncExchange responseTrigger,
                final HttpContext context) throws HttpException, IOException {
            synchronized (httpExchange) {
                Exception ex = httpExchange.getException();
                if (ex != null) {
                    System.out.println("[client<-proxy] " + httpExchange.getId() + " " + ex);
                    int status = HttpStatus.SC_INTERNAL_SERVER_ERROR;
                    HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_0, status,
                            EnglishReasonPhraseCatalog.INSTANCE.getReason(status, Locale.US));
                    String message = ex.getMessage();
                    if (message == null) {
                        message = "Unexpected error";
                    }
                    response.setEntity(new NStringEntity(message, ContentType.DEFAULT_TEXT));
                    responseTrigger.submitResponse(new BasicAsyncResponseProducer(response));
                    System.out.println("[client<-proxy] " + httpExchange.getId() + " error response triggered");
                }
                HttpResponse response = httpExchange.getResponse();
                if (response != null) {
                    responseTrigger.submitResponse(new ProxyResponseProducer(httpExchange));
                    System.out.println("[client<-proxy] " + httpExchange.getId() + " response triggered");
                }
                // No response yet.
                httpExchange.setResponseTrigger(responseTrigger);
            }
        }

    }

    static class ProxyRequestConsumer implements HttpAsyncRequestConsumer<ProxyHttpExchange> {

        private final ProxyHttpExchange httpExchange;
        private final HttpAsyncRequester executor;
        private final BasicNIOConnPool connPool;

        private volatile boolean completed;

        public ProxyRequestConsumer(
                final ProxyHttpExchange httpExchange,
                final HttpAsyncRequester executor,
                final BasicNIOConnPool connPool) {
            super();
            this.httpExchange = httpExchange;
            this.executor = executor;
            this.connPool = connPool;
        }

        public void close() throws IOException {
        }

        public void requestReceived(final HttpRequest request) {
            synchronized (this.httpExchange) {
                System.out.println("[client->proxy] " + this.httpExchange.getId() + " " + request.getRequestLine());
                this.httpExchange.setRequest(request);
                this.executor.execute(
                        new ProxyRequestProducer(this.httpExchange),
                        new ProxyResponseConsumer(this.httpExchange),
                        this.connPool);
            }
        }

        public void consumeContent(
                final ContentDecoder decoder, final IOControl ioctrl) throws IOException {
            synchronized (this.httpExchange) {
                this.httpExchange.setClientIOControl(ioctrl);
                // Receive data from the client
                ByteBuffer buf = this.httpExchange.getInBuffer();
                int n = decoder.read(buf);
                System.out.println("[client->proxy] " + this.httpExchange.getId() + " " + n + " bytes read");
                if (decoder.isCompleted()) {
                    System.out.println("[client->proxy] " + this.httpExchange.getId() + " content fully read");
                }
                // If the buffer is full, suspend client input until there is free
                // space in the buffer
                if (!buf.hasRemaining()) {
                    ioctrl.suspendInput();
                    System.out.println("[client->proxy] " + this.httpExchange.getId() + " suspend client input");
                }
                // If there is some content in the input buffer make sure origin
                // output is active
                if (buf.position() > 0) {
                    if (this.httpExchange.getOriginIOControl() != null) {
                        this.httpExchange.getOriginIOControl().requestOutput();
                        System.out.println("[client->proxy] " + this.httpExchange.getId() + " request origin output");
                    }
                }
            }
        }

        public void requestCompleted(final HttpContext context) {
            synchronized (this.httpExchange) {
                this.completed = true;;
                System.out.println("[client->proxy] " + this.httpExchange.getId() + " request completed");
                this.httpExchange.setRequestReceived();
                if (this.httpExchange.getOriginIOControl() != null) {
                    this.httpExchange.getOriginIOControl().requestOutput();
                    System.out.println("[client->proxy] " + this.httpExchange.getId() + " request origin output");
                }
            }
        }

        public Exception getException() {
            return null;
        }

        public ProxyHttpExchange getResult() {
            return this.httpExchange;
        }

        public boolean isDone() {
            return this.completed;
        }

        public void failed(final Exception ex) {
            System.out.println("[client->proxy] " + ex.toString());
        }

    }

    static class ProxyRequestProducer implements HttpAsyncRequestProducer {

        private final ProxyHttpExchange httpExchange;

        public ProxyRequestProducer(final ProxyHttpExchange httpExchange) {
            super();
            this.httpExchange = httpExchange;
        }

        public void close() throws IOException {
        }

        public HttpHost getTarget() {
            synchronized (this.httpExchange) {
                return this.httpExchange.getTarget();
            }
        }

        public HttpRequest generateRequest() {
            synchronized (this.httpExchange) {
                HttpRequest request = this.httpExchange.getRequest();
                System.out.println("[proxy->origin] " + this.httpExchange.getId() + " " + request.getRequestLine());
                // Rewrite request!!!!
                if (request instanceof HttpEntityEnclosingRequest) {
                    BasicHttpEntityEnclosingRequest r = new BasicHttpEntityEnclosingRequest(
                            request.getRequestLine());
                    r.setEntity(((HttpEntityEnclosingRequest) request).getEntity());
                    return r;
                } else {
                    return new BasicHttpRequest(request.getRequestLine());
                }
            }
        }

        public void produceContent(
                final ContentEncoder encoder, final IOControl ioctrl) throws IOException {
            synchronized (this.httpExchange) {
                this.httpExchange.setOriginIOControl(ioctrl);
                // Send data to the origin server
                ByteBuffer buf = this.httpExchange.getInBuffer();
                buf.flip();
                int n = encoder.write(buf);
                buf.compact();
                System.out.println("[proxy->origin] " + this.httpExchange.getId() + " " + n + " bytes written");
                // If there is space in the buffer and the message has not been
                // transferred, make sure the client is sending more data
                if (buf.hasRemaining() && !this.httpExchange.isRequestReceived()) {
                    if (this.httpExchange.getClientIOControl() != null) {
                        this.httpExchange.getClientIOControl().requestInput();
                        System.out.println("[proxy->origin] " + this.httpExchange.getId() + " request client input");
                    }
                }
                if (buf.position() == 0) {
                    if (this.httpExchange.isRequestReceived()) {
                        encoder.complete();
                        System.out.println("[proxy->origin] " + this.httpExchange.getId() + " content fully written");
                    } else {
                        // Input buffer is empty. Wait until the client fills up
                        // the buffer
                        ioctrl.suspendOutput();
                        System.out.println("[proxy->origin] " + this.httpExchange.getId() + " suspend origin output");
                    }
                }
            }
        }

        public void requestCompleted(final HttpContext context) {
            synchronized (this.httpExchange) {
                System.out.println("[proxy->origin] " + this.httpExchange.getId() + " request completed");
            }
        }

        public boolean isRepeatable() {
            return false;
        }

        public void resetRequest() {
        }

        public void failed(final Exception ex) {
            System.out.println("[proxy->origin] " + ex.toString());
        }

    }

    static class ProxyResponseConsumer implements HttpAsyncResponseConsumer<ProxyHttpExchange> {

        private final ProxyHttpExchange httpExchange;

        private volatile boolean completed;

        public ProxyResponseConsumer(final ProxyHttpExchange httpExchange) {
            super();
            this.httpExchange = httpExchange;
        }

        public void close() throws IOException {
        }

        public void responseReceived(final HttpResponse response) {
            synchronized (this.httpExchange) {
                System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " " + response.getStatusLine());
                this.httpExchange.setResponse(response);
                HttpAsyncExchange responseTrigger = this.httpExchange.getResponseTrigger();
                if (responseTrigger != null && !responseTrigger.isCompleted()) {
                    System.out.println("[client<-proxy] " + this.httpExchange.getId() + " response triggered");
                    responseTrigger.submitResponse(new ProxyResponseProducer(this.httpExchange));
                }
            }
        }

        public void consumeContent(
                final ContentDecoder decoder, final IOControl ioctrl) throws IOException {
            synchronized (this.httpExchange) {
                this.httpExchange.setOriginIOControl(ioctrl);
                // Receive data from the origin
                ByteBuffer buf = this.httpExchange.getOutBuffer();
                int n = decoder.read(buf);
                System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " " + n + " bytes read");
                if (decoder.isCompleted()) {
                    System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " content fully read");
                }
                // If the buffer is full, suspend origin input until there is free
                // space in the buffer
                if (!buf.hasRemaining()) {
                    ioctrl.suspendInput();
                    System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " suspend origin input");
                }
                // If there is some content in the input buffer make sure client
                // output is active
                if (buf.position() > 0) {
                    if (this.httpExchange.getClientIOControl() != null) {
                        this.httpExchange.getClientIOControl().requestOutput();
                        System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " request client output");
                    }
                }
            }
        }

        public void responseCompleted(final HttpContext context) {
            synchronized (this.httpExchange) {
                if (this.completed) {
                    return;
                }
                this.completed = true;
                System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " response completed");
                this.httpExchange.setResponseReceived();
                if (this.httpExchange.getClientIOControl() != null) {
                    this.httpExchange.getClientIOControl().requestOutput();
                    System.out.println("[proxy<-origin] " + this.httpExchange.getId() + " request client output");
                }
            }
        }

        public void failed(final Exception ex) {
            synchronized (this.httpExchange) {
                if (this.completed) {
                    return;
                }
                this.completed = true;
                this.httpExchange.setException(ex);
                HttpAsyncExchange responseTrigger = this.httpExchange.getResponseTrigger();
                if (responseTrigger != null && !responseTrigger.isCompleted()) {
                    System.out.println("[client<-proxy] " + this.httpExchange.getId() + " " + ex);
                    int status = HttpStatus.SC_INTERNAL_SERVER_ERROR;
                    HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_0, status,
                            EnglishReasonPhraseCatalog.INSTANCE.getReason(status, Locale.US));
                    String message = ex.getMessage();
                    if (message == null) {
                        message = "Unexpected error";
                    }
                    response.setEntity(new NStringEntity(message, ContentType.DEFAULT_TEXT));
                    responseTrigger.submitResponse(new BasicAsyncResponseProducer(response));
                }
            }
        }

        public boolean cancel() {
            synchronized (this.httpExchange) {
                if (this.completed) {
                    return false;
                }
                failed(new InterruptedIOException("Cancelled"));
                return true;
            }
        }

        public ProxyHttpExchange getResult() {
            return this.httpExchange;
        }

        public Exception getException() {
            return null;
        }

        public boolean isDone() {
            return this.completed;
        }

    }

    static class ProxyResponseProducer implements HttpAsyncResponseProducer {

        private final ProxyHttpExchange httpExchange;

        public ProxyResponseProducer(final ProxyHttpExchange httpExchange) {
            super();
            this.httpExchange = httpExchange;
        }

        public void close() throws IOException {
            this.httpExchange.reset();
        }

        public HttpResponse generateResponse() {
            synchronized (this.httpExchange) {
                HttpResponse response = this.httpExchange.getResponse();
                System.out.println("[client<-proxy] " + this.httpExchange.getId() + " " + response.getStatusLine());
                // Rewrite response!!!!
                BasicHttpResponse r = new BasicHttpResponse(response.getStatusLine());
                r.setEntity(response.getEntity());
                return r;
            }
        }

        public void produceContent(
                final ContentEncoder encoder, final IOControl ioctrl) throws IOException {
            synchronized (this.httpExchange) {
                this.httpExchange.setClientIOControl(ioctrl);
                // Send data to the client
                ByteBuffer buf = this.httpExchange.getOutBuffer();
                buf.flip();
                int n = encoder.write(buf);
                buf.compact();
                System.out.println("[client<-proxy] " + this.httpExchange.getId() + " " + n + " bytes written");
                // If there is space in the buffer and the message has not been
                // transferred, make sure the origin is sending more data
                if (buf.hasRemaining() && !this.httpExchange.isResponseReceived()) {
                    if (this.httpExchange.getOriginIOControl() != null) {
                        this.httpExchange.getOriginIOControl().requestInput();
                        System.out.println("[client<-proxy] " + this.httpExchange.getId() + " request origin input");
                    }
                }
                if (buf.position() == 0) {
                    if (this.httpExchange.isResponseReceived()) {
                        encoder.complete();
                        System.out.println("[client<-proxy] " + this.httpExchange.getId() + " content fully written");
                    } else {
                        // Input buffer is empty. Wait until the origin fills up
                        // the buffer
                        ioctrl.suspendOutput();
                        System.out.println("[client<-proxy] " + this.httpExchange.getId() + " suspend client output");
                    }
                }
            }
        }

        public void responseCompleted(final HttpContext context) {
            synchronized (this.httpExchange) {
                System.out.println("[client<-proxy] " + this.httpExchange.getId() + " response completed");
            }
        }

        public void failed(final Exception ex) {
            System.out.println("[client<-proxy] " + ex.toString());
        }

    }

    static class ProxyIncomingConnectionReuseStrategy extends DefaultConnectionReuseStrategy {

        @Override
        public boolean keepAlive(final HttpResponse response, final HttpContext context) {
            NHttpConnection conn = (NHttpConnection) context.getAttribute(
                    ExecutionContext.HTTP_CONNECTION);
            boolean keepAlive = super.keepAlive(response, context);
            if (keepAlive) {
                System.out.println("[client->proxy] connection kept alive " + conn);
            }
            return keepAlive;
        }

    };

    static class ProxyOutgoingConnectionReuseStrategy extends DefaultConnectionReuseStrategy {

        @Override
        public boolean keepAlive(final HttpResponse response, final HttpContext context) {
            NHttpConnection conn = (NHttpConnection) context.getAttribute(
                    ExecutionContext.HTTP_CONNECTION);
            boolean keepAlive = super.keepAlive(response, context);
            if (keepAlive) {
                System.out.println("[proxy->origin] connection kept alive " + conn);
            }
            return keepAlive;
        }

    };

    static class ProxyServiceHandler extends HttpAsyncService {

        public ProxyServiceHandler(
                final HttpProcessor httpProcessor,
                final ConnectionReuseStrategy reuseStrategy,
                final HttpAsyncRequestHandlerResolver handlerResolver,
                final HttpParams params) {
            super(httpProcessor, reuseStrategy, handlerResolver, params);
        }

        @Override
        protected void log(final Exception ex) {
            ex.printStackTrace();
        }

        @Override
        public void connected(final NHttpServerConnection conn) {
            System.out.println("[client->proxy] connection open " + conn);
            super.connected(conn);
        }

        @Override
        public void closed(final NHttpServerConnection conn) {
            System.out.println("[client->proxy] connection closed " + conn);
            super.closed(conn);
        }

    }

    static class ProxyClientProtocolHandler extends HttpAsyncRequestExecutor {

        public ProxyClientProtocolHandler() {
            super();
        }

        @Override
        protected void log(final Exception ex) {
            ex.printStackTrace();
        }

        @Override
        public void connected(final NHttpClientConnection conn,
                final Object attachment) throws IOException, HttpException {
            System.out.println("[proxy->origin] connection open " + conn);
            super.connected(conn, attachment);
        }

        @Override
        public void closed(final NHttpClientConnection conn) {
            System.out.println("[proxy->origin] connection closed " + conn);
            super.closed(conn);
        }

    }

    static class ProxyConnPool extends BasicNIOConnPool {

        public ProxyConnPool(final ConnectingIOReactor ioreactor, final HttpParams params) {
            super(ioreactor, params);
        }

        public ProxyConnPool(
                final ConnectingIOReactor ioreactor,
                final NIOConnFactory<HttpHost, NHttpClientConnection> connFactory,
                final HttpParams params) {
            super(ioreactor, connFactory, params);
        }

        @Override
        public void release(final BasicNIOPoolEntry entry, boolean reusable) {
            System.out.println("[proxy->origin] connection released " + entry.getConnection());
            super.release(entry, reusable);
            StringBuilder buf = new StringBuilder();
            PoolStats totals = getTotalStats();
            buf.append("[total kept alive: ").append(totals.getAvailable()).append("; ");
            buf.append("total allocated: ").append(totals.getLeased() + totals.getAvailable());
            buf.append(" of ").append(totals.getMax()).append("]");
            System.out.println("[proxy->origin] " + buf.toString());
        }

    }

}

最后

以上就是飞快心锁为你收集整理的HttpCore组件案例程序(Java描述) (Http Components- HttpCore Examples) 转：http://www.myexception.cn/program/586831.html HttpCore组件案例程序(Java描述) (Http Components- HttpCore Examples) 一、基本概念 二、源代码详解 的全部内容，希望文章能够帮你解决HttpCore组件案例程序(Java描述) (Http Components- HttpCore Examples) 转：http://www.myexception.cn/program/586831.html HttpCore组件案例程序(Java描述) (Http Components- HttpCore Examples) 一、基本概念 二、源代码详解 所遇到的程序开发问题。

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