java http请求

package com.expai.utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.util.Map;
import java.util.Map.Entry;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Description:后台服务要调用其他架构服务post请求服务类
 */
public class HttpPostUtils {
    
    private static Logger logger = LoggerFactory.getLogger(HttpPostUtils.class);
    
    /**
     * 发送请求
     * @param url
     * @param params
     * @return
     */
    public static String sendPost(String url,Map<String,String> params){
        
        logger.debug("sendPost======================开始===========");
        URL u = null;
        HttpURLConnection con = null;
        //构建请求参数
        StringBuffer sb = new StringBuffer();
        if(params != null){
            for(Entry<String,String>e:params.entrySet()){
                sb.append(e.getKey());
                sb.append("=");
                sb.append(e.getValue());
                sb.append("&");
            }
            sb.substring(0, sb.length()-1);
        }
        logger.debug("send_url:"+url);
        logger.debug("send_data:"+sb.toString());
        //发送请求
        try {
            u = new URL(url);
            con = (HttpURLConnection)u.openConnection();
            con.setRequestMethod("GET");
            con.setDoInput(true);
            con.setDoOutput(true);
            con.setUseCaches(false);
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            OutputStreamWriter osw = new OutputStreamWriter(con.getOutputStream(), "UTF-8");
            osw.write(sb.toString());
            osw.flush();
            osw.close();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (ProtocolException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(con!=null){
                con.disconnect();
            }
        }
        
        //读取返回的参数
        StringBuffer buffer = new StringBuffer();
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    con.getInputStream(), "UTF-8"));
            String temp;
            while ((temp = br.readLine()) != null) {
                buffer.append(temp);
                buffer.append("\n");
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        return buffer.toString();
        
    }
    
}