HttpClient详细解释

Http协议的重要性相信不用我多说了，HttpClient相比传统JDK自带的URLConnection，增加了易用性和灵活性（具体区别，日后我们再讨论），它不仅是客户端发送Http请求变得容易，而且也方便了开发人员测试接口（基于Http协议的），即提高了开发的效率，也方便提高代码的健壮性。因此熟练掌握HttpClient是很重要的必修内容，掌握HttpClient后，相信对于Http协议的了解会更加深入。

org.apache.commons.httpclient.HttpClient与org.apache.http.client.HttpClient的区别

 Commons的HttpClient项目现在是生命的尽头，不再被开发,
 已被Apache HttpComponents项目HttpClient和的HttpCore
 模组取代，提供更好的性能和更大的灵活性。

一、简介

HttpClient是Apache Jakarta Common下的子项目，用来提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包，并且它支持HTTP协议最新的版本和建议。HttpClient已经应用在很多的项目中，比如Apache Jakarta上很著名的另外两个开源项目Cactus和HTMLUnit都使用了HttpClient。

下载地址: http://hc.apache.org/downloads.cgi

二、特性

1. 基于标准、纯净的java语言。实现了Http1.0和Http1.1

2. 以可扩展的面向对象的结构实现了Http全部的方法（GET, POST, PUT, DELETE, HEAD, OPTIONS, and TRACE）。

3. 支持HTTPS协议。

4. 通过Http代理建立透明的连接。

5. 利用CONNECT方法通过Http代理建立隧道的https连接。

6. Basic, Digest, NTLMv1, NTLMv2, NTLM2 Session, SNPNEGO/Kerberos认证方案。

7. 插件式的自定义认证方案。

8. 便携可靠的套接字工厂使它更容易的使用第三方解决方案。

9. 连接管理器支持多线程应用。支持设置最大连接数，同时支持设置每个主机的最大连接数，发现并关闭过期的连接。

10. 自动处理Set-Cookie中的Cookie。

11. 插件式的自定义Cookie策略。

12. Request的输出流可以避免流中内容直接缓冲到socket服务器。

13. Response的输入流可以有效的从socket服务器直接读取相应内容。

14. 在http1.0和http1.1中利用KeepAlive保持持久连接。

15. 直接获取服务器发送的response code和 headers。

16. 设置连接超时的能力。

17. 实验性的支持http1.1 response caching。

18. 源代码基于Apache License 可免费获取。

三、使用方法

使用HttpClient发送请求、接收响应很简单，一般需要如下几步即可。

1. 创建HttpClient对象。

2. 创建请求方法的实例，并指定请求URL。如果需要发送GET请求，创建HttpGet对象；如果需要发送POST请求，创建HttpPost对象。

3. 如果需要发送请求参数，可调用HttpGet、HttpPost共同的setParams(HetpParams params)方法来添加请求参数；对于HttpPost对象而言，也可调用setEntity(HttpEntity entity)方法来设置请求参数。

4. 调用HttpClient对象的execute(HttpUriRequest request)发送请求，该方法返回一个HttpResponse。

5. 调用HttpResponse的getAllHeaders()、getHeaders(String name)等方法可获取服务器的响应头；调用HttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。

6. 释放连接。无论执行方法是否成功，都必须释放连接

相关jar包

 commons-cli-1.2.jar
 commons-codec-1.9.jar
 commons-logging-1.2.jar
 fluent-hc-4.5.1.jar
 httpclient-4.5.1.jar
 httpclient-cache-4.5.1.jar
 httpclient-win-4.5.1.jar
 httpcore-4.4.3.jar
 httpcore-ab-4.4.3.jar
 httpcore-nio-4.4.3.jar
 httpmime-4.5.1.jar
 jna-4.1.0.jar
 jna-platform-4.1.0.jar

最简单post请求, 源自 http://my.oschina.net/xinxingegeya/blog/282683

 package a;

 import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Properties;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.impl.client.DefaultHttpClient;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.util.EntityUtils;

 public class First {
     public static void main(String[] args) throws Exception{
         List formparams = new ArrayList();
         formparams.add(new BasicNameValuePair("account", ""));
         formparams.add(new BasicNameValuePair("password", ""));
         HttpEntity reqEntity = new UrlEncodedFormEntity(formparams, "utf-8");

         RequestConfig requestConfig = RequestConfig.custom()
         .setConnectTimeout(5000)//一、连接超时：connectionTimeout-->指的是连接一个url的连接等待时间
                 .setSocketTimeout(5000)// 二、读取数据超时：SocketTimeout-->指的是连接上一个url，获取response的返回等待时间
                 .setConnectionRequestTimeout(5000)
                 .build();

         HttpClient client = new DefaultHttpClient();
         HttpPost post = new HttpPost("http://cnivi.com.cn/login");
         post.setEntity(reqEntity);
         post.setConfig(requestConfig);
         HttpResponse response = client.execute(post);

         if (response.getStatusLine().getStatusCode() == 200) {
             HttpEntity resEntity = response.getEntity();
             String message = EntityUtils.toString(resEntity, "utf-8");
             System.out.println(message);
         } else {
             System.out.println("请求失败");
         }
     }

 }

四、实例

主文件

 package com.test;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.security.KeyManagementException;
 import java.security.KeyStore;
 import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
 import java.security.cert.CertificateException;
 import java.util.ArrayList;
 import java.util.List;
 import javax.net.ssl.SSLContext;
 import org.apache.http.HttpEntity;
 import org.apache.http.NameValuePair;
 import org.apache.http.ParseException;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
 import org.apache.http.conn.ssl.SSLContexts;
 import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.mime.MultipartEntityBuilder;
 import org.apache.http.entity.mime.content.FileBody;
 import org.apache.http.entity.mime.content.StringBody;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.util.EntityUtils;
 import org.apache.http.client.config.RequestConfig;
 import org.junit.Test;
 public class HttpClientTest {
 　　//方法见下........
 }

HttpClientUtils工具类

 package com.bobo.code.web.controller.technology.httpcomponents;


 import org.apache.http.HttpEntity;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.client.methods.RequestBuilder;
 import org.apache.http.conn.routing.HttpRoute;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.util.EntityUtils;

 import java.io.IOException;
 import java.util.*;

 public class HttpClientUtils {

     private static PoolingHttpClientConnectionManager connectionManager = null;
     private static HttpClientBuilder httpBuilder = null;
     private static RequestConfig requestConfig = null;

     private static int MAXCONNECTION = 10;

     private static int DEFAULTMAXCONNECTION = 5;

     private static String IP = "cnivi.com.cn";
     private static int PORT = 80;

     static {
         //设置http的状态参数
         requestConfig = RequestConfig.custom()
                 .setSocketTimeout(5000)
                 .setConnectTimeout(5000)
                 .setConnectionRequestTimeout(5000)
                 .build();

         HttpHost target = new HttpHost(IP, PORT);
         connectionManager = new PoolingHttpClientConnectionManager();
         connectionManager.setMaxTotal(MAXCONNECTION);//客户端总并行链接最大数
         connectionManager.setDefaultMaxPerRoute(DEFAULTMAXCONNECTION);//每个主机的最大并行链接数
         connectionManager.setMaxPerRoute(new HttpRoute(target), 20);
         httpBuilder = HttpClients.custom();
         httpBuilder.setConnectionManager(connectionManager);
     }

     public static CloseableHttpClient getConnection() {
         CloseableHttpClient httpClient = httpBuilder.build();
         return httpClient;
     }


     public static HttpUriRequest getRequestMethod(Map map, String url, String method) {
         List params = new ArrayList();
         Set> entrySet = map.entrySet();
         for (Map.Entry e : entrySet) {
             String name = e.getKey();
             String value = e.getValue();
             NameValuePair pair = new BasicNameValuePair(name, value);
             params.add(pair);
         }
         HttpUriRequest reqMethod = null;
         if ("post".equals(method)) {
             reqMethod = RequestBuilder.post().setUri(url)
                     .addParameters(params.toArray(new BasicNameValuePair[params.size()]))
                     .setConfig(requestConfig).build();
         } else if ("get".equals(method)) {
             reqMethod = RequestBuilder.get().setUri(url)
                     .addParameters(params.toArray(new BasicNameValuePair[params.size()]))
                     .setConfig(requestConfig).build();
         }
         return reqMethod;
     }

     public static void main(String args[]) throws IOException {
         Map map = new HashMap();
         map.put("account", "");
         map.put("password", "");

         HttpClient client = getConnection();
         HttpUriRequest post = getRequestMethod(map, "http://cnivi.com.cn/login", "post");
         HttpResponse response = client.execute(post);

         if (response.getStatusLine().getStatusCode() == 200) {
             HttpEntity entity = response.getEntity();
             String message = EntityUtils.toString(entity, "utf-8");
             System.out.println(message);
         } else {
             System.out.println("请求失败");
         }
     }
 }

get方式

 /**
      * 发送 get请求
      */
     public void get() {
         CloseableHttpClient httpclient = HttpClients.createDefault();
         try {
             // 创建httpget.
             HttpGet httpget = new HttpGet("http://www.baidu.com/");
             System.out.println("executing request " + httpget.getURI());
             // 执行get请求.
             CloseableHttpResponse response = httpclient.execute(httpget);
             try {
                 // 获取响应实体
                 HttpEntity entity = response.getEntity();
                 System.out.println("--------------------------------------");
                 // 打印响应状态
                 System.out.println(response.getStatusLine());
                 if (entity != null) {
                     // 打印响应内容长度
                     System.out.println("Response content length: " + entity.getContentLength());
                     // 打印响应内容
                     System.out.println("Response content: " + EntityUtils.toString(entity));
                 }
                 System.out.println("------------------------------------");
             } finally {
                 response.close();
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (ParseException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             // 关闭连接,释放资源
             try {
                 httpclient.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

post方式

 /**
      * 发送 post请求访问本地应用并根据传递参数不同返回不同结果
      */
     public void post() {
         // 创建默认的httpClient实例.
         CloseableHttpClient httpclient = HttpClients.createDefault();
         // 创建httppost
         HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceJ.action");
         // 创建参数队列
         List formparams = new ArrayList();
         formparams.add(new BasicNameValuePair("type", "house"));
         UrlEncodedFormEntity uefEntity;
         try {
             uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
             httppost.setEntity(uefEntity);
             System.out.println("executing request " + httppost.getURI());
             CloseableHttpResponse response = httpclient.execute(httppost);
             try {
                 HttpEntity entity = response.getEntity();
                 if (entity != null) {
                     System.out.println("--------------------------------------");
                     System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
                     System.out.println("--------------------------------------");
                 }
             } finally {
                 response.close();
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (UnsupportedEncodingException e1) {
             e1.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             // 关闭连接,释放资源
             try {
                 httpclient.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

post方式乱码补充　

如果有乱码,可以偿试使用 StringEntity 来替换HttpEntity:

 StringEntity content =new StringEntity(soapRequestData.toString(), Charset.forName("UTF-8"));// 第二个参数，设置后才会对，内容进行编码
         content.setContentType("application/soap+xml; charset=UTF-8");
         content.setContentEncoding("UTF-8");
         httppost.setEntity(content);

具体SOAP协议代码如下:

 package com.isoftstone.core.service.impl;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.nio.charset.Charset;
 import java.util.Scanner;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.entity.EntityBuilder;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.util.EntityUtils;
 import org.apache.log4j.Logger;
 import org.jdom.Document;
 import org.jdom.Element;

 import com.isoftstone.core.common.constant.RequestConstants;
 import com.isoftstone.core.common.tools.XmlTool;
 import com.isoftstone.core.service.intf.ServiceOfStringPara;
 /**
  * 德勤定价系统,由核心主动调用
  * @author King
  *
  */
 public class DeloittePricingSingleCarImpl implements ServiceOfStringPara {
     private  String serviceUrl = "http://10.30.0.35:7001/ZSInsUW/Auto/PricingService";

     private static Logger log = Logger.getLogger(DeloittePricingSingleCarImpl.class.getName());

     public String invoke(String sRequest) {

         StringBuffer soapRequestData = new StringBuffer();
         soapRequestData.append(");
         soapRequestData.append("  xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" ");
         soapRequestData.append("  xmlns:prov=\"http://provider.webservice.zsins.dtt.com/\">");
         soapRequestData.append("  ");
         soapRequestData.append("");
         soapRequestData.append("");
         soapRequestData.append("");
         soapRequestData.append(" + sRequest + "]]>");
         soapRequestData.append("");
         soapRequestData.append("");
         soapRequestData.append(" ");
         soapRequestData.append("");

         HttpClient httpclient = HttpClients.createDefault();
         HttpPost httppost = new HttpPost(serviceUrl);

         StringEntity content =new StringEntity(soapRequestData.toString(), Charset.forName("UTF-8"));// 第二个参数，设置后才会对，内容进行编码
         content.setContentType("application/soap+xml; charset=UTF-8");
         content.setContentEncoding("UTF-8");
         httppost.setEntity(content);

         //用下面的服务器端以UTF-8接收到的报文会乱码,原因未知
 //        HttpEntity reqEntity = EntityBuilder.create().setContentType(
 //                ContentType.TEXT_PLAIN) // .TEXT_PLAIN
 //                .setText(soapRequestData.toString()).build();
 //        httppost.setEntity(reqEntity);
 //        httppost.addHeader("Content-Type",
 //                "application/soap+xml; charset=utf-8");
         HttpResponse response = null;
         Document doc = null;
         String returnXml = null;
         String sentity = null;
         try {
             response = httpclient.execute(httppost);
             HttpEntity resEntity = response.getEntity();
             if (resEntity != null) {
                 sentity = EntityUtils.toString(resEntity, "UTF-8");
                 doc = XmlTool.getDocument(sentity, RequestConstants.ENCODE);
                 System.out.println(doc.toString());
                 Element eRoot = doc.getRootElement();
                 Element body = eRoot.getChild("Body", eRoot.getNamespace());
                 Element resp = (Element) body.getChildren().get(0);
                 Element returnele = resp.getChild("return");
                 returnXml = returnele.getText().toString();
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             log.info("发送给德勤定价系统的请求报文：\n" + soapRequestData.toString());
             log.info("德勤定价系统返回的响应报文：\n" + sentity);
             log.info("返回给核心的的报文:\n" + returnXml);
         }
         return returnXml;
     }


     public String getServiceUrl() {
         return serviceUrl;
     }


     public void setServiceUrl(String serviceUrl) {
         this.serviceUrl = serviceUrl;
     }


     public static void main(String[] args) throws Exception{
         File file = new File("D:/浙商项目资料/z浙江资料/t唐建华/德勤定价调试报文.txt");
         System.out.println(file.exists());

         String temp2 = null;
         StringBuilder sb2 = new StringBuilder();
         InputStreamReader isr = new InputStreamReader(new FileInputStream(file),"GBK");
         BufferedReader br = new BufferedReader(isr);
         temp2 = br.readLine();

         while( temp2 != null ){
             sb2.append(temp2);
             temp2 = br.readLine();
         }
         String sss = sb2.toString();
 //        System.out.println(sss.toString());
         new DeloittePricingSingleCarImpl().invoke(sss);
     }
 }

post提交表单

 /**
      * post方式提交表单（模拟用户登录请求）
      */
     public void postForm() {
         // 创建默认的httpClient实例.
         CloseableHttpClient httpclient = HttpClients.createDefault();
         // 创建httppost
         HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceJ.action");
         // 创建参数队列
         List formparams = new ArrayList();
         formparams.add(new BasicNameValuePair("username", "admin"));
         formparams.add(new BasicNameValuePair("password", "123456"));
         UrlEncodedFormEntity uefEntity;
         try {
             uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
             httppost.setEntity(uefEntity);
             System.out.println("executing request " + httppost.getURI());
             CloseableHttpResponse response = httpclient.execute(httppost);
             try {
                 HttpEntity entity = response.getEntity();
                 if (entity != null) {
                     System.out.println("--------------------------------------");
                     System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
                     System.out.println("--------------------------------------");
                 }
             } finally {
                 response.close();
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (UnsupportedEncodingException e1) {
             e1.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             // 关闭连接,释放资源
             try {
                 httpclient.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

文件上传

 /**
      * 上传文件
      */
     public void upload() {
         CloseableHttpClient httpclient = HttpClients.createDefault();
         try {
             HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceFile.action");

             FileBody bin = new FileBody(new File("F:\\image\\sendpix0.jpg"));
             StringBody comment = new StringBody("A binary file of some kind", ContentType.TEXT_PLAIN);

             HttpEntity reqEntity = MultipartEntityBuilder.create().addPart("bin", bin).addPart("comment", comment).build();

             httppost.setEntity(reqEntity);

             System.out.println("executing request " + httppost.getRequestLine());
             CloseableHttpResponse response = httpclient.execute(httppost);
             try {
                 System.out.println("----------------------------------------");
                 System.out.println(response.getStatusLine());
                 HttpEntity resEntity = response.getEntity();
                 if (resEntity != null) {
                     System.out.println("Response content length: " + resEntity.getContentLength());
                 }
                 EntityUtils.consume(resEntity);
             } finally {
                 response.close();
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             try {
                 httpclient.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

ssl连接

 /**
      * HttpClient连接SSL
      */
     public void ssl() {
         CloseableHttpClient httpclient = null;
         try {
             KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
             FileInputStream instream = new FileInputStream(new File("d:\\tomcat.keystore"));
             try {
                 // 加载keyStore d:\\tomcat.keystore
                 trustStore.load(instream, "123456".toCharArray());
             } catch (CertificateException e) {
                 e.printStackTrace();
             } finally {
                 try {
                     instream.close();
                 } catch (Exception ignore) {
                 }
             }
             // 相信自己的CA和所有自签名的证书
             SSLContext sslcontext = SSLContexts.custom().loadTrustMaterial(trustStore, new TrustSelfSignedStrategy()).build();
             // 只允许使用TLSv1协议
             SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslcontext, new String[] { "TLSv1" }, null,
                     SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
             httpclient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
             // 创建http请求(get方式)
             HttpGet httpget = new HttpGet("https://localhost:8443/myDemo/Ajax/serivceJ.action");
             System.out.println("executing request" + httpget.getRequestLine());
             CloseableHttpResponse response = httpclient.execute(httpget);
             try {
                 HttpEntity entity = response.getEntity();
                 System.out.println("----------------------------------------");
                 System.out.println(response.getStatusLine());
                 if (entity != null) {
                     System.out.println("Response content length: " + entity.getContentLength());
                     System.out.println(EntityUtils.toString(entity));
                     EntityUtils.consume(entity);
                 }
             } finally {
                 response.close();
             }
         } catch (ParseException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } catch (KeyManagementException e) {
             e.printStackTrace();
         } catch (NoSuchAlgorithmException e) {
             e.printStackTrace();
         } catch (KeyStoreException e) {
             e.printStackTrace();
         } finally {
             if (httpclient != null) {
                 try {
                     httpclient.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         }
     }

关于RequestConfig的配置:  

源自:  

http://segmentfault.com/a/1190000000587944

http://blog.csdn.net/walkerjong/article/details/51710945

 public void requestConfig(){
 //      新建一个RequestConfig：
         RequestConfig defaultRequestConfig = RequestConfig.custom()
             //一、连接目标服务器超时时间：ConnectionTimeout-->指的是连接一个url的连接等待时间
             .setConnectTimeout(5000)
             //二、读取目标服务器数据超时时间：SocketTimeout-->指的是连接上一个url，获取response的返回等待时间
             .setSocketTimeout(5000)
             //三、从连接池获取连接的超时时间:ConnectionRequestTimeout
             .setConnectionRequestTimeout(5000)
             .build();

 //      这个超时可以设置为客户端级别,作为所有请求的默认值：
         CloseableHttpClient httpclient = HttpClients.custom()
             .setDefaultRequestConfig(defaultRequestConfig)
             .build();
 //       httpclient.execute(httppost);的时候可以让httppost直接享受到httpclient中的默认配置.

 //      Request不会继承客户端级别的请求配置，所以在自定义Request的时候，需要将客户端的默认配置拷贝过去：
         HttpGet httpget = new HttpGet("http://www.apache.org/");
         RequestConfig requestConfig = RequestConfig.copy(defaultRequestConfig)
             .setProxy(new HttpHost("myotherproxy", 8080))
             .build();
         httpget.setConfig(requestConfig);
 //      httpget可以单独地使用新copy的requestConfig请求配置,不会对别的request请求产生影响
     }

httpGet或httpPost 的abort()和releaseConnection()差异

 //httpPost.abort();//中断请求,接下来可以开始另一段请求,所以个人理应,用这个应该可以在session中虚拟登录
  //httpPost.releaseConnection();//释放请求.如果释放了相当于要清空session

根所以上差异,可知模拟登录可以如下:  源自 http://bbs.csdn.net/topics/390195343

 package com.bms.core;

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;

 import org.apache.http.Consts;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.impl.client.DefaultHttpClient;
 import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.util.EntityUtils;

 import com.bms.util.CommonUtil;

 public class Test2 {

     /**
      * @param args
      * @throws IOException
      * @throws ClientProtocolException
      */
     public static void main(String[] args) throws ClientProtocolException, IOException {
         DefaultHttpClient httpclient = new DefaultHttpClient();

          HttpGet httpGet = new HttpGet("http://www.baidu.com");
          String body = "";
          HttpResponse response;
          HttpEntity entity;
          response = httpclient.execute(httpGet);
          entity = response.getEntity();
          body = EntityUtils.toString(entity);//这个就是页面源码了
          httpGet.abort();//中断请求,接下来可以开始另一段请求
          System.out.println(body);
          //httpGet.releaseConnection();//释放请求.如果释放了相当于要清空session
          //以下是post方法
          HttpPost httpPost = new HttpPost("http://www.baidu.com");//一定要改成可以提交的地址,这里用百度代替
          List  nvps = new ArrayList ();
          nvps.add(new BasicNameValuePair("name", "1"));//名值对
          nvps.add(new BasicNameValuePair("account", "xxxx"));
          httpPost.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8));
          response = httpclient.execute(httpPost);
          entity = response.getEntity();
          body = EntityUtils.toString(entity);
          System.out.println("Login form get: " + response.getStatusLine());//这个可以打印状态
          httpPost.abort();
          System.out.println(body);
          httpPost.releaseConnection();
     }

 }

源自  http://blog.csdn.net/wangpeng047/article/details/19624529#reply

其它相关资料: 非CloseableHttpClient  HTTPClient模块的HttpGet和HttpPost

HttpClient 4.3教程

我的源码

httpclient异常情况分析

我项目中用到的HttpClientUtil (2016/12/17)

 package com.isoftstone.pcis.isc.util;

 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.net.UnknownHostException;

 import javax.net.ssl.SSLException;
 import javax.net.ssl.SSLHandshakeException;

 import org.apache.http.HttpEntityEnclosingRequest;
 import org.apache.http.HttpRequest;
 import org.apache.http.NoHttpResponseException;
 import org.apache.http.client.HttpRequestRetryHandler;
 import org.apache.http.client.protocol.HttpClientContext;
 import org.apache.http.config.Registry;
 import org.apache.http.config.RegistryBuilder;
 import org.apache.http.conn.ConnectTimeoutException;
 import org.apache.http.conn.socket.ConnectionSocketFactory;
 import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
 import org.apache.http.conn.socket.PlainConnectionSocketFactory;
 import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
 import org.apache.http.protocol.HttpContext;
 import com.isoftstone.pcis.isc.util.ProperUtil;

 public class HttpClientUtil {

     private static CloseableHttpClient httpclient = null;

     static final int maxTotal=Integer.valueOf(ProperUtil.get("maxTotal")).intValue();//总最大连接数
     static final int defaultMaxPerRoute=Integer.valueOf(ProperUtil.get("corePoolSize")).intValue();//每条线路最大连接数 = 本系统核心线程数 , 这样永远不会超过最大连接

      public static CloseableHttpClient getHttpClient() {

             if (null == httpclient) {
                 synchronized (HttpClientUtil.class) {
                     if (null == httpclient) {
                         httpclient = getNewHttpClient();
                     }
                 }
             }

             return httpclient;
         }

        private static CloseableHttpClient getNewHttpClient() {


             // 设置连接池
             ConnectionSocketFactory plainsf = PlainConnectionSocketFactory.getSocketFactory();
             LayeredConnectionSocketFactory sslsf = SSLConnectionSocketFactory.getSocketFactory();
             Registry registry = RegistryBuilder. create().register("http", plainsf).register("https", sslsf).build();
             PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(registry);
             // 配置最大连接数
             cm.setMaxTotal(maxTotal);
             // 配置每条线路的最大连接数
             cm.setDefaultMaxPerRoute(defaultMaxPerRoute);

             // 请求重试处理
             HttpRequestRetryHandler httpRequestRetryHandler = new HttpRequestRetryHandler() {
                 @Override
                 public boolean retryRequest(IOException exception,
                         int executionCount, HttpContext context) {
                     if (executionCount >= 2) {// 如果已经重试了2次，就放弃
                         return false;
                     }
                     if (exception instanceof NoHttpResponseException) {// 如果服务器丢掉了连接，那么就重试
                         return true;
                     }
                     if (exception instanceof SSLHandshakeException) {// 不要重试SSL握手异常
                         return false;
                     }
                     if (exception instanceof InterruptedIOException) {// 超时
                         return false;
                     }
                     if (exception instanceof UnknownHostException) {// 目标服务器不可达
                         return false;
                     }
                     if (exception instanceof ConnectTimeoutException) {// 连接被拒绝
                         return false;
                     }
                     if (exception instanceof SSLException) {// SSL握手异常
                         return false;
                     }

                     HttpClientContext clientContext = HttpClientContext.adapt(context);
                     HttpRequest request = clientContext.getRequest();

                     if (!(request instanceof HttpEntityEnclosingRequest)) {
                         return true;
                     }
                     return false;
                 }

             };

             CloseableHttpClient newHttpclient=null;

                 newHttpclient = HttpClients.custom()
                                            .setConnectionManager(cm)
 //                                           .setDefaultRequestConfig(requestConfig)
                                            .setRetryHandler(httpRequestRetryHandler)
                                            .build();

              return newHttpclient;
        }
 }

我自己整理的HttpClientTool (2017/06/01)

 package com.isoftstone.core.util;

 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.net.UnknownHostException;

 import javax.net.ssl.SSLException;
 import javax.net.ssl.SSLHandshakeException;

 import org.apache.http.HttpEntityEnclosingRequest;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
 import org.apache.http.NoHttpResponseException;
 import org.apache.http.client.HttpRequestRetryHandler;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.protocol.HttpClientContext;
 import org.apache.http.config.Registry;
 import org.apache.http.config.RegistryBuilder;
 import org.apache.http.conn.ConnectTimeoutException;
 import org.apache.http.conn.routing.HttpRoute;
 import org.apache.http.conn.socket.ConnectionSocketFactory;
 import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
 import org.apache.http.conn.socket.PlainConnectionSocketFactory;
 import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
 import org.apache.http.protocol.HttpContext;

 /**
  * org.apache.http.impl.client.CloseableHttpClient链接池生成工具
  * @reference http://www.cnblogs.com/whatlonelytear/articles/4835538.html
  * @author King
  * @date 20170601
  */
 public class HttpClientTool {

     // org.apache.http.impl.client.CloseableHttpClient
     private static CloseableHttpClient httpclient = null;

     // 这里就直接默认固定了,因为以下三个参数在新建的method中仍然可以重新配置并被覆盖.
     static final int connectionRequestTimeout = 5000;// ms毫秒,从池中获取链接超时时间
     static final int connectTimeout = 5000;// ms毫秒,建立链接超时时间
     static final int socketTimeout = 30000;// ms毫秒,读取超时时间

     // 总配置,主要涉及是以下两个参数,如果要作调整没有用到properties会比较后麻烦,但鉴于一经粘贴,随处可用的特点,就不再做依赖性配置化处理了.
     // 而且这个参数同一家公司基本不会变动.
     static final int maxTotal = 500;// 最大总并发,很重要的参数
     static final int maxPerRoute = 100;// 每路并发,很重要的参数

     // 正常情况这里应该配成MAP或LIST
     // 细化配置参数,用来对每路参数做精细化处理,可以管控各ip的流量,比如默认配置请求baidu:80端口最大100个并发链接,
     static final String detailHostName = "http://www.baidu.com";// 每个细化配置之ip(不重要,在特殊场景很有用)
     static final int detailPort = 80;// 每个细化配置之port(不重要,在特殊场景很有用)
     static final int detailMaxPerRoute = 100;// 每个细化配置之最大并发数(不重要,在特殊场景很有用)

     public static CloseableHttpClient getHttpClient() {
         if (null == httpclient) {
             synchronized (HttpClientTool.class) {
                 if (null == httpclient) {
                     httpclient = init();
                 }
             }
         }
         return httpclient;
     }

     /**
      * 链接池初始化 这里最重要的一点理解就是. 让CloseableHttpClient 一直活在池的世界里, 但是HttpPost却一直用完就消掉.
      * 这样可以让链接一直保持着.
      *
      * @return
      */
     private static CloseableHttpClient init() {
         CloseableHttpClient newHttpclient = null;

         // 设置连接池
         ConnectionSocketFactory plainsf = PlainConnectionSocketFactory.getSocketFactory();
         LayeredConnectionSocketFactory sslsf = SSLConnectionSocketFactory.getSocketFactory();
         Registry registry = RegistryBuilder. create().register("http", plainsf).register("https", sslsf).build();
         PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(registry);
         // 将最大连接数增加
         cm.setMaxTotal(maxTotal);
         // 将每个路由基础的连接增加
         cm.setDefaultMaxPerRoute(maxPerRoute);

         // 细化配置开始,其实这里用Map或List的for循环来配置每个链接,在特殊场景很有用.
         // 将每个路由基础的连接做特殊化配置,一般用不着
         HttpHost httpHost = new HttpHost(detailHostName, detailPort);
         // 将目标主机的最大连接数增加
         cm.setMaxPerRoute(new HttpRoute(httpHost), detailMaxPerRoute);
         // cm.setMaxPerRoute(new HttpRoute(httpHost2),
         // detailMaxPerRoute2);//可以有细化配置2
         // cm.setMaxPerRoute(new HttpRoute(httpHost3),
         // detailMaxPerRoute3);//可以有细化配置3
         // 细化配置结束

         // 请求重试处理
         HttpRequestRetryHandler httpRequestRetryHandler = new HttpRequestRetryHandler() {
             @Override
             public boolean retryRequest(IOException exception, int executionCount, HttpContext context) {
                 if (executionCount >= 2) {// 如果已经重试了2次，就放弃
                     return false;
                 }
                 if (exception instanceof NoHttpResponseException) {// 如果服务器丢掉了连接，那么就重试
                     return true;
                 }
                 if (exception instanceof SSLHandshakeException) {// 不要重试SSL握手异常
                     return false;
                 }
                 if (exception instanceof InterruptedIOException) {// 超时
                     return false;
                 }
                 if (exception instanceof UnknownHostException) {// 目标服务器不可达
                     return false;
                 }
                 if (exception instanceof ConnectTimeoutException) {// 连接被拒绝
                     return false;
                 }
                 if (exception instanceof SSLException) {// SSL握手异常
                     return false;
                 }

                 HttpClientContext clientContext = HttpClientContext.adapt(context);
                 HttpRequest request = clientContext.getRequest();
                 // 如果请求是幂等的，就再次尝试
                 if (!(request instanceof HttpEntityEnclosingRequest)) {
                     return true;
                 }
                 return false;
             }
         };

         // 配置请求的超时设置
         RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(connectionRequestTimeout).setConnectTimeout(connectTimeout).setSocketTimeout(socketTimeout).build();
         newHttpclient = HttpClients.custom().setConnectionManager(cm).setDefaultRequestConfig(requestConfig).setRetryHandler(httpRequestRetryHandler).build();
         return newHttpclient;
     }
 }