在Java领域，谈到网络编程，可能大家脑海里第一反应是MINA，NETTY，GRIZZLY等的开源框架。没错，不过在深入探究这些框架之前，我们需要先从original的技术探究开始(当然，需要大家先熟悉java.net.*类库)。这里，我要和大家分享一下HttpComponents项目的部分组件特性。HttpClient，想必大家早都接触过了吧。HttpComponents和HttpClient的”血缘“有点像guava和google-collection的关系。目前，HttpComponents已经是Apache的项目了，它旨在为我们提供一个Http协议相关的Java平台工具集。它的代码组织很精妙，主要分两部分，一部分是核心工具集(包括HttpCore-bio，HttpCore-nio，HttpClient，HttpMIme，HttpCookie等)，一部分是扩展工具集(目前主要包括ssl)

　　HttpClient主要包括Connection management，Status management，Authentication Management三部分。下面给出对它的二次封装，经过了线上的接近半年的验证(这里指的是httpClient 3，httpClient 4还有待检验)，可以看做是一个高性能的Client封装吧。感兴趣的朋友可以根据apache的MPM IO模型进行部分参数的调整。

　　先来段httpClient 4的封装，代码如下:

　　[java] view plaincopyprint?

　　/**

　　* @author von gosling 2012-3-2

　　*/

　　public class HttpComponentsClientExecutor implements DisposableBean {

　　private static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 100;

　　private static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5; //notice IE 6，7，8

　　private static final int DEFAULT_CONN_TIMEOUT_MILLISECONDS = 5 * 1000;

　　private static final int DEFAULT_READ_TIMEOUT_MILLISECONDS = 60 * 1000;

　　private static final String HTTP_HEADER_CONTENT_ENCODING = "Content-Encoding";

　　private static final String ENCODING_GZIP = "gzip";

　　private HttpClient httpClient;

　　/**

　　* Create a new instance of the HttpComponentsClient with a default

　　* {@link HttpClient} that uses a default

　　* {@link org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager}.

　　*/

　　public HttpComponentsClientExecutor() {

　　SchemeRegistry schemeRegistry = new SchemeRegistry();

　　schemeRegistry.register(new Scheme("http"， 80， PlainSocketFactory.getSocketFactory()));

　　schemeRegistry.register(new Scheme("https"， 443， SSLSocketFactory.getSocketFactory()));

　　ThreadSafeClientConnManager connectionManager = new ThreadSafeClientConnManager(

　　schemeRegistry);

　　connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL_CONNECTIONS);

　　connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_CONNECTIONS_PER_ROUTE);

　　this.httpClient = new DefaultHttpClient(connectionManager);

　　setConnectTimeout(DEFAULT_CONN_TIMEOUT_MILLISECONDS);

　　setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);

　　}

　　/**

　　* Create a new instance of the HttpComponentsClient with the given

　　* {@link HttpClient} instance.

　　*

　　* @param httpClient the HttpClient instance to use for this request

　　*/

　　public HttpComponentsClientExecutor(HttpClient httpClient) {

　　Validate.notNull(httpClient， "HttpClient must not be null");

　　//notice: if you want to custom exception recovery mechanism

　　//you should provide an implementation of the HttpRequestRetryHandler interface.

　　this.httpClient = httpClient;

　　}

　　/**

　　* Set the {@code HttpClient} used by this request.

　　*/

　　public void setHttpClient(HttpClient httpClient) {

　　this.httpClient = httpClient;

　　}

　　/**

　　* Return the {@code HttpClient} used by this request.

　　*/

　　public HttpClient getHttpClient() {

　　return this.httpClient;

　　}

　　/**

　　* Set the connection timeout for the underlying HttpClient. A timeout value

　　* of 0 specifies an infinite timeout.

　　*

　　* @param timeout the timeout value in milliseconds

　　*/

　　public void setConnectTimeout(int timeout) {

　　Validate.isTrue(timeout >= 0， "Timeout must be a non-negative value");

　　getHttpClient().getParams().setIntParameter(CoreConnectionPNames.CONNECTION_TIMEOUT，

　　timeout);

　　}

　　/**

　　* Set the socket timeout (SO_TIMEOUT) in milliseconds， which is the timeout

　　* for waiting for data or， put differently， a maximum period inactivity

　　* between two consecutive data packets.A timeout value of 0 specifies an

　　* infinite timeout.

　　*

　　* @param timeout the timeout value in milliseconds

　　*/

　　public void setReadTimeout(int timeout) {

　　Validate.isTrue(timeout >= 0， "Timeout must be a non-negative value");