Http请求封装（对HttpClient类的进一步封装，使之调用更方便。另外，此类管理唯一的HttpClient对象，支持线程池调用，效率更高）

 package com.ad.ssp.engine.common;

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

 import org.apache.http.Header;
 import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.message.BasicHeader;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

 import com.adwm.lib.http.HttpClient;
 import com.adwm.lib.http.HttpResult;

 /**
  * 对HttpClient类的进一步封装，使之调用更方便。另外，此类管理唯一的HttpClient对象，支持线程池调用，效率更高
  *
  *
  */
 public class HttpClientUtil {
     private static final Logger logger = LogManager.getLogger(HttpClientUtil.class);

 //    private static HttpClient client = new HttpClient(600);
     private static HttpClient client = new HttpClient();

     public static HttpClient getInstance() {
         return client;
     }

     /**
      * form方式提交http post请求
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param postParams
      *            body请求参数集合
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 返回的http body体经utf8编码后的字符串
      */
     public static String postKVParams1(String targetUrl, Map<String, String> headers, Map<String, Object> postParams,
             int timeout) {
         List<Header> headerList = getHeaderList(headers);
         try {
             HttpResult hr = client.post(targetUrl, headerList, postParams, timeout);
             if (hr.getStatus() == 200)
                 return hr.getContentAsString();
             else {
                 logger.warn("The request url is: {}, its reponse code is: {}", targetUrl, hr.getStatus());
             }
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }

         return null;
     }

     private static List<Header> getHeaderList(Map<String, String> headers) {
         if (headers != null && headers.size() > 0) {
             List<Header> headerList = new ArrayList<Header>();
             for (Entry<String, String> entry : headers.entrySet()) {
                 headerList.add(new BasicHeader(entry.getKey(), entry.getValue()));
             }
             return headerList;
         }

         return null;
     }

     /**
      * form方式提交http post请求
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param postParams
      *            body请求参数集合
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 未处理的HttpResult对象，供调用方自己解析和处理
      */
     public static HttpResult postKVParams2(String targetUrl, Map<String, String> headers,
             Map<String, Object> postParams, int timeout) {
         List<Header> headerList = getHeaderList(headers);
         try {
             return client.post(targetUrl, headerList, postParams, timeout);
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }

         return null;
     }

     /**
      * 用post方法提交json字符串参数
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param jsonBody
      *            json字符串
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 返回的http body体经utf8编码后的字符串
      */
     public static String postJsonParams1(String targetUrl, Map<String, String> headers, String jsonBody, int timeout)  throws Exception {
         List<Header> headerList = getHeaderList(headers);

         StringEntity entity = new StringEntity(jsonBody, "UTF-8");
         entity.setContentType("application/json");
         entity.setContentEncoding("UTF-8");
         HttpResult httpRst = client.post(targetUrl, headerList, entity, timeout);
         if(httpRst.getStatus() == ResponseCodeUtil.HTTP_STATUS_OK)
             return httpRst.getContentAsString();
         else {
             logger.warn("The request url is: {}, its reponse code is: {}", targetUrl, httpRst.getStatus());
         }

         return null;
     }

     /**
      * 用post方法提交json字符串参数
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param jsonBody
      *            json字符串
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 未处理的HttpResult对象，供调用方自己解析和处理
      */
     public static HttpResult postJsonParams2(String targetUrl, Map<String, String> headers, String jsonBody,
             int timeout)  throws Exception {
         List<Header> headerList = getHeaderList(headers);
         StringEntity entity = new StringEntity(jsonBody, "UTF-8");
         entity.setContentType("application/json");
         return client.post(targetUrl, headerList, entity, timeout);
     }

     /**
      * 通过POST方式发起protocol请求
      * @param url
      * @param headers
      * @param content
      * @param timeout
      * @return
      */
     public static byte[] postProtobuf(String url, Map<String, String> headers, byte[] content, int timeout)  throws Exception {
         List<Header> headerList = getHeaderList(headers);
         ByteArrayEntity entity = new ByteArrayEntity(content, ContentType.APPLICATION_OCTET_STREAM);
         HttpResult httpResult = client.post(url, headerList, entity, timeout);
         if (httpResult.getStatus() == ResponseCodeUtil.HTTP_STATUS_OK){
             return httpResult.getContent();
         } else {
             logger.warn("The request url is: {}, its reponse code is: {}", url, httpResult.getStatus());
         }
         return null;
     }

     /**
      * 以get方法请求url
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 返回的http body体经utf8编码后的字符串
      */
     public static String get1(String targetUrl, Map<String, String> headers, int timeout) throws Exception {
         List<Header> headerList = getHeaderList(headers);
         HttpResult httpRst = client.get(targetUrl, headerList, timeout);
         if(httpRst.getStatus() == ResponseCodeUtil.HTTP_STATUS_OK)
             return httpRst.getContentAsString();
         else {
             logger.warn("The request url is: {}, its reponse code is: {}", targetUrl, httpRst.getStatus());
         }
         return null;
     }

     /**
      * 以get方法请求url
      *
      * @param targetUrl
      *            目标url地址
      * @param headers
      *            header请求参数集合
      * @param timeout
      *            超时时间（单位为毫秒）
      * @return 未处理的HttpResult对象，供调用方自己解析和处理
      */
     public static HttpResult get2(String targetUrl, Map<String, String> headers, int timeout) throws Exception {
         List<Header> headerList = getHeaderList(headers);
         return client.get(targetUrl, headerList, timeout);
     }

 }