Java如何发起http请求的实现(GET/POST)

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.List;
import java.util.Map;

public class HttpRequest {
 
 public static String sendGet(String url, String param) {
  String result = "";
  BufferedReader in = null;
  try {
   String urlNameString = url + "?" + param;
   URL realUrl = new URL(urlNameString);
   // 打开和URL之间的连接
   URLConnection connection = realUrl.openConnection();
   // 设置通用的请求属性
   connection.setRequestProperty("accept", "*
 public static String sendPost(String url, String param) {
  PrintWriter out = null;
  BufferedReader in = null;
  String result = "";
  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
   conn.setRequestProperty("accept", "*/*");
   conn.setRequestProperty("connection", "Keep-Alive");
   conn.setRequestProperty("user-agent",
     "Mozilla/4.0 (compatible; MSIE 6.0; windows NT 5.1;SV1)");
   // 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
   in = new BufferedReader(
     new InputStreamReader(conn.getInputStream()));
   String line;
   while ((line = in.readLine()) != null) {
    result += line;
   }
  } 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;
 }
}

#app的路由地址"/show"即为ajax中定义的url地址，采用POST、GET方法均可提交
@app.route("/show",methods=["GET", "POST"])
def show():
 #首先获取前端传入的name数据
 if request.method == "POST":
  name = request.fORM.get("name")
 if request.method == "GET":
  name = request.args.get("name")
 #创建Database类的对象sql，test为需要访问的数据库名字 具体可见Database类的构造函数
 sql = Database("test")
 try:
  #执行sql语句 多说一句，f+字符串的形式，可以在字符串里面以{}的形式加入变量名 结果保存在result数组中
  result = sql.execute(f"SELECT type FROM type WHERE name='{name}'")
 except Exception as e:
  return {'status':"error", 'message': "code error"}
 else:
  if not len(result) == 0:
   #这个result，我觉得也可以把它当成数据表，查询的结果至多一个，result[0][0]返回数组中的第一行第一列
   return {'status':'success','message':result[0][0]}
  else:
   return "rbq"
   

 	 //创建发起http请求对象
  HttpRequest h = new HttpRequest();
  //向121.41.111.94/show发起POST请求，并传入name参数
  String content = h.sendPost("http://121.41.111.94/show","name=张新宇");
  System.out.println(content);   

<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>fastjson</artifactId>
 <version>1.2.28</version>
</dependency>
   

import com.alibaba.fastjson.JSONObject;
JSONObject jsonObject = JSONObject.parseObject(content);
System.out.println(jsonObject);
System.out.println(jsonObject.getString("message"));