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HttpClient使用详细教程

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

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：
" + soapRequestData.toString());
            log.info("德勤定价系统返回的响应报文：
" + sentity);
            log.info("返回给核心的的报文:
" + 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

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

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

FROM:http://www.cnblogs.com/whatlonelytear/articles/4835538.html

查看全文

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原文地址：https://www.cnblogs.com/jepson6669/p/9358244.html

HttpClient使用详细教程

一、简介

二、特性

三、使用方法

相关jar包

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

四、实例

主文件

HttpClientUtils工具类

get方式

post方式

post方式乱码补充

post提交表单

文件上传

ssl连接

关于RequestConfig的配置:

我项目中用到的HttpClientUtil (2016/12/17)

我自己整理的HttpClientTool (2017/06/01)

异常列表

post方式乱码补充　