Make a simple Postman to implement interface testing

package com.xxxx.controller;

/**
 * @author yc
 * @date 2022/3/11 17:45
 */
import net.sf.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;
import java.util.Map;

public class LoginPostman {

    public static String sendPost(String url, Map<String, Object> param, String charset) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        String line;
        StringBuffer sb=new StringBuffer();
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性 设置请求格式
            conn.setRequestProperty("contentType", charset);
            conn.setRequestProperty("content-type", "application/x-www-form-urlencoded");
            //设置超时时间
//            conn.setConnectTimeout(60);
//            conn.setReadTimeout(60);
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 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    设置接收格式
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream(),charset));
            while ((line = in.readLine()) != null) {
                sb.append(line);
            }
            result=sb.toString();
        } catch (Exception e) {
            System.out.println("发送 POST请求出现异常!"+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;
    }
    public static void main(String[] args) {
        String postUrl = "公网IP/javaProject2/LoginServlet";
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("login_stnum","***");
        map.put("login_input_password","***");
//        map.put("sex","男");
        JSONObject jsonMap = JSONObject.fromObject(map);
        System.out.println("map转换json:"+jsonMap);
        System.out.println("Post请求返回数据:"+ sendPost(postUrl, jsonMap, "utf-8"));
    }
}