http实现发送post请求，获取结果集

 package com.ming;

 import java.io.BufferedReader;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.Map;

 public class HttpBaseUtil {

     /**
      * 向指定的url发送post方法,并获取放回值
      * @param url 发送的url
      * @param param 发送的参数 参数形式a=2&b=2
      * @param head 请求头设定
      */
     public static String sendPostUrl(String url,String param,Map<String, String> head) throws Exception{
         StringBuffer result=new StringBuffer();
         PrintWriter out =null;
         BufferedReader in=null;
         try {
             URL realUrl = new URL(url);
             // 打开和URL之间的连接
             HttpURLConnection  conn =(HttpURLConnection)realUrl.openConnection();
             // 设置通用的请求属性
             conn.setRequestProperty("accept", "*/*");
             conn.setRequestProperty("connection", "Keep-Alive");
             conn.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
             if(head!=null && !head.isEmpty()){
                 for (String key:head.keySet()){
                     conn.setRequestProperty(key, head.get(key));
                 }
             }
             conn.setDoOutput(true);
             conn.setDoInput(true);
             // 获取URLConnection对象对应的输出流
             out = new PrintWriter(new OutputStreamWriter(conn.getOutputStream(),"UTF-8"));
             // 发送请求参数
             out.print(param);
             // flush输出流的缓冲
             out.flush();
             // 定义BufferedReader输入流来读取URL的响应
             in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
             String line;
             while ((line = in.readLine()) != null) {
                 result.append(line);
             }
         } catch (Exception e) {
             throw new Exception("发送post出现异常."+e.getMessage());
         }
         return result.toString();
     }

 }

 import org.apache.http.HttpResponse;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.ResponseHandler;
 import org.apache.http.client.methods.HttpUriRequest;

 import java.io.IOException;

 public class LocalHttpClient {

     private static LocalHttpClient localHttpClient;
     protected HttpClient httpClient;

     private static int maxTotal = ;
     private static int maxPerRoute = ;
     public static void init(int maxTotal,int maxPerRoute){
         LocalHttpClient.maxTotal = maxTotal;
         LocalHttpClient.maxPerRoute = maxPerRoute;
     }

     public static LocalHttpClient getInstance(){
         if(localHttpClient != null){
             return localHttpClient;
         }else{
             localHttpClient = new LocalHttpClient();
             if(maxTotal > ){
                 localHttpClient.httpClient = HttpClientFactory.createHttpClient(maxTotal,maxPerRoute);
             }else{
                 localHttpClient.httpClient = HttpClientFactory.createHttpClient();
             }
             return localHttpClient;
         }
     }

     public HttpResponse execute(HttpUriRequest request){
         try {
             return httpClient.execute(request);
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
         return null;
     }

     public <T> T execute(HttpUriRequest request,ResponseHandler<T> responseHandler){
         try {
             return httpClient.execute(request, responseHandler);
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
         return null;
     }
 }