HttpClient使用详解总结大全①

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.jarcommons-codec-1.9.jarcommons-logging-1.2.jarfluent-hc-4.5.1.jarhttpclient-4.5.1.jarhttpclient-cache-4.5.1.jarhttpclient-win-4.5.1.jarhttpcore-4.4.3.jarhttpcore-ab-4.4.3.jarhttpcore-nio-4.4.3.jarhttpmime-4.5.1.jarjna-4.1.0.jarjna-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<NameValuePair> formparams = new ArrayList<NameValuePair>();        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<String, String> map, String url, String method) {        List<NameValuePair> params = new ArrayList<NameValuePair>();        Set<Map.Entry<String, String>> entrySet = map.entrySet();        for (Map.Entry<String, String> 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<String, String> map = new HashMap<String, String>();        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<NameValuePair> formparams = new ArrayList<NameValuePair>();         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("<soapenv:Envelope");        soapRequestData.append("  xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" ");        soapRequestData.append("  xmlns:prov=\"http://provider.webservice.zsins.dtt.com/\">");        soapRequestData.append(" <soapenv:Header/> ");        soapRequestData.append("<soapenv:Body>");        soapRequestData.append("<prov:executePrvPricing>");        soapRequestData.append("<arg0>");        soapRequestData.append("<![CDATA[" + sRequest + "]]>");        soapRequestData.append("</arg0>");        soapRequestData.append("</prov:executePrvPricing>");        soapRequestData.append(" </soapenv:Body>");        soapRequestData.append("</soapenv:Envelope>");        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<NameValuePair> formparams = new ArrayList<NameValuePair>();         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 <NameValuePair> nvps = new ArrayList <NameValuePair>();         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<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> 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<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> 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;    }}

异常列表

 

异常

中文翻译

继承自java.io.IOException

Apache 

org.apache.http.conn.HttpHostConnectException

主机不存在(ping不通)

是

Apache 

org.apache.http.conn.ConnectTimeoutException

主机存在,但无法建立链接

是

Apache 

java.net.SocketTimeoutException

连上主机(但读取超时)

是

    

UrlConnection 

java.net.SocketTimeoutException:

主机不存在(ping不通)

是

UrlConnection 

java.net.SocketTimeoutException:

连上主机(但读取超时)

是

 

请求地址

异常

后台

原因

http://localhost:8080/httpserver

ok

不断点

正常

http://localhost:8080/httpserver

java.net.SocketTimeoutException

故意断点

超过3秒,建立链接成功,读取返回信息超时

http://2.2.2.2:8080/httpserver

org.apache.http.conn.ConnectTimeoutException

不存在

ip不存在

http://localhost:8090/httpserver

org.apache.http.conn.HttpHostConnectException

不存在

ip存在,端口不存在

 

 

 而服务端返回HTTP/1.1 404 Not Found 代表能连上主机,只是目标主机没有提供这个服务(请求的服务路径可能写错)

 响应状态500,501,502,503等解释

博文转自：http://www.cnblogs.com/whatlonelytear/articles/4835538.html