java发送psot请求：

package com.tea.web.admin;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.URL;import java.util.HashMap;import java.util.Map;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONObject;public class PsotTest {        public static void main(String[] args) {        HashMap
     
       params = new HashMap<>();        params.put("customerType", 2);        params.put("token", "3d88f30fb4d129027ca5f9c04ed5b733");        params.put("sign", "94257c28f256fbb66b4efd889d1d09be2");        String result = sendPost("http://api.teayk.com/sys/api/customerGrade/findGradeByType", params);        System.err.println(result);    }    private static String sendPost(String url, Map
      
        params) {        OutputStreamWriter out = null;        BufferedReader in = null;                StringBuilder result = new StringBuilder();         try {            HttpURLConnection conn =(HttpURLConnection) new URL(url).openConnection();            //发送POST请求必须设置如下两行            conn.setDoOutput(true);            conn.setDoInput(true);            conn.setRequestMethod("POST");//POST方法            //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)");            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");            conn.connect();            //获取URLConnection对象对应的输出流            out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");            //发送请求参数                        if (params != null) {                 /*                   StringBuilder param = new StringBuilder();                   for (Map.Entry
       
         entry : params.entrySet()) {                      if(param.length()>0){                          param.append("&");                      }                                        param.append(entry.getKey());                      param.append("=");                      param.append(entry.getValue());                                            System.out.println(entry.getKey()+":"+entry.getValue());                  }                  System.out.println("param:"+param.toString());                  out.write(param.toString());                 */                                JSONObject json =(JSONObject) JSON.toJSON(params);                System.out.println(json);                out.write(json.toString());            }            out.flush();// flush输出流的缓冲            // 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) {                        e.printStackTrace();        }        //使用finally块来关闭输出流、输入流        finally{            try{                if(out!=null){ out.close();}                if(in!=null){in.close();}            }catch(IOException ex){                ex.printStackTrace();            }        }        return result.toString();    }}