Maven + Spring mvc：后端向前端传递数据

「爱情、让人受尽委屈。」 2021-06-24 16:10 465阅读 0赞

前端从后端请求数据，基本思想，依旧是通过ajax将java返回的数据，显示在前端。  
首先，在后端提供一个接口:/getHelloWorld，返回hello字符串，代码如下：

package com.iotzzh.controller;
    
    import org.springframework.stereotype.Controller;
    
    import java.awt.List;
    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.Map;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.ResponseBody;
    import com.iotzzh.entity.User;
    
    
    @Controller
    // look for hello page.
    @RequestMapping("/hello")
    
    public class HelloWorldController {
        
        @RequestMapping("/getHelloWorld")
        @ResponseBody
        public String getHelloWorld() throws IOException{
    //      map.put("name", "zhang");
    //        map.put("password", "12345678");
            System.out.println("success");
            return "hello";
        }
    
        @RequestMapping(value="/helloworld", method=RequestMethod.POST, produces="application/json;charset=utf-8")
        @ResponseBody
        public void helloworld(@RequestBody User user) {
            System.out.println("success");
            System.out.println(user);
        }
        
         @RequestMapping("/helloworld")
            public String helloworld(){
                System.out.println("nihao");
                return "hello";
            }
    
    }

前端调用该接口，并将数据弹出，代码如下：

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
       pageEncoding="ISO-8859-1"%>
    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="ISO-8859-1">
    <title>Insert title here</title>
    <script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
    <script type="text/javascript">
       $(function(){
           $("button").click(function(){
               $.ajax({
                   type:"POST",
                   url:"helloworld",
                   contentType:"application/json;charset=utf-8",
                   dataType:"json",
                   data:JSON.stringify({
                           "Name": "test", 
                           "Password": "123456", 
                           "Address": "SD"                     
                   }),
                   success:function(){
                       console.log("success");
                   }
               });
           });
       });
       $(function(){
           $("#getData").click(function(){
               $.ajax({
                   type:"GET",
                   url:"getHelloWorld",
                   success:function(data){
                       console.log("success");
                       alert("Data: " + data);
                   }
               });
           });
       });
    </script>
    </head>
    <body>
       <h1>hello world.</h1>
       <button>Click</button>
       <div id = "getData">getdataFromJava</div>
    </body>
    
    </html>

显示：

![2789632-183446805aaad5b4.png][]

[2789632-183446805aaad5b4.png]: /images/20210615/932c230d43a44aabb3c0637035af170e.png