使用HttpCore（HttpComponents）在android上构建webService

使用HttpCore可以非常简单的构建HttpServer，HttpCore可以处理Http协议层。

工程里需要引入httpcore.jar，客户端开发需要引入httpclient.jar，下载地址：http://hc.apache.org/downloads.cgi。

服务器端代码如下（get请求返回“<xml><method>get</method><url>&uri</url></xml>"， post请求返回“<xml><method>post</method><url>&uri</url></xml>"）：

package com.mytest.http;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.BasicHttpParams;import org.apache.http.params.CoreConnectionPNames;import org.apache.http.params.CoreProtocolPNames;import org.apache.http.params.HttpParams;import org.apache.http.protocol.BasicHttpContext;import org.apache.http.protocol.HttpContext;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 HttpServer {public static void main(String[] args) throws Exception {Thread t = new RequestListenerThread(8080);t.setDaemon(false);t.start();//start the webservice server}static class WebServiceHandler implements HttpRequestHandler {public WebServiceHandler() {super();}public void handle(final HttpRequest request,final HttpResponse response, final HttpContext context)throws HttpException, IOException {String method = request.getRequestLine().getMethod().toUpperCase(Locale.ENGLISH);//get uriString target = request.getRequestLine().getUri();if (method.equals("GET") ) {response.setStatusCode(HttpStatus.SC_OK);StringEntity entity = new StringEntity("<xml><method>get</method><url>" + target + "</url></xml>");response.setEntity(entity);}else if (method.equals("POST") ){response.setStatusCode(HttpStatus.SC_OK);StringEntity entity = new StringEntity("<xml><method>post</method><url>" + target + "</url></xml>");response.setEntity(entity);}else{throw new MethodNotSupportedException(method+ " method not supported");}}}static class RequestListenerThread extends Thread {private final ServerSocket serversocket;private final HttpParams params;private final HttpService httpService;public RequestListenerThread(int port)throws IOException {// this.serversocket = new ServerSocket(port);// Set up the HTTP protocol processorHttpProcessor httpproc = new ImmutableHttpProcessor(new HttpResponseInterceptor[] {new ResponseDate(), new ResponseServer(),new ResponseContent(), new ResponseConnControl() });this.params = new BasicHttpParams();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 request handlersHttpRequestHandlerRegistry reqistry = new HttpRequestHandlerRegistry();reqistry.register("*", new WebServiceHandler());  //WebServiceHandler用来处理webservice请求。this.httpService = new HttpService(httpproc,new DefaultConnectionReuseStrategy(),new DefaultHttpResponseFactory());httpService.setParams(this.params);httpService.setHandlerResolver(reqistry);//为http服务设置注册好的请求处理器。}@Overridepublic void run() {System.out.println("Listening on port "+ this.serversocket.getLocalPort());System.out.println("Thread.interrupted = " + Thread.interrupted()); while (!Thread.interrupted()) {try {// Set up HTTP connectionSocket socket = this.serversocket.accept();DefaultHttpServerConnection conn = new DefaultHttpServerConnection();System.out.println("Incoming connection from "+ socket.getInetAddress());conn.bind(socket, this.params);// Start worker threadThread 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;}@Overridepublic 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) {}}}}}

客户端代码如下（注意，在android 3.0及其后版本中，此端代码不能在main主线程里工作，否则会报网络异常导致退出）：

DefaultHttpClient client = new DefaultHttpClient();HttpGet httpGet = new HttpGet(”http://localhost:8080/“);HttpResponse httpResponse = client.execute(httpGet);if (httpResponse.getStatusLine().getStatusCode() == 200) {response = EntityUtils.toString(httpResponse.getEntity());}