Spring Boot之 Controller 接收参数和返回数据总结(包括上传、下载文件)

转载自 https://blog.csdn.net/jy02268879/article/details/82830789

一、接收参数（postman发送）

1.form表单

@RequestParam("name") String name

会把传递过来的Form表单中的name对应到formData方法的name参数上

该注解不能接收json传参

该注解表示name字段是必须入参的，否则会报错

@RequestParam(value = "name", required = false) String name

required = false表示必须入参

@RequestParam(value = "name", defaultValue = "admin") String name

defaultValue = "admin"表示当name入参为空的时候给它一个默认值admin

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 测试接收form表单、URL的数据。不能接收Json数据
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/test1", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     public String formData(@RequestParam("name") String name , @RequestParam("age") int age){
    
    
   
   


   
   
   
   

    
    

     
             String result = 
     
     "receive name = "+name+
     
     " age = "+age;
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(result);
    
    
   
   


   
   
   
   

    
    
        
     
     return result;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

2.URL

代码跟1.form表单中的代码一样

3.动态接收URL中的数据

@PathVariable将URL中的占位符参数绑定到控制器处理方法的入参

此种情况下，url求情中一定要带占位符pageNo,pageSize的值，不然访问失败

即访问时一定要用 http://localhost:8088/sid/test2/2/20

如果用 http://localhost:8088/sid/test2 则访问失败

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 测试动态接收URL中的数据
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/test2/{pageNo}/{pageSize}", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     public String urlData(@PathVariable int pageNo , @PathVariable int pageSize){
    
    
   
   


   
   
   
   

    
    

     
             String result = 
     
     "receive pageNo = "+pageNo+
     
     " pageSize = "+pageSize;
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(result);
    
    
   
   


   
   
   
   

    
    
        
     
     return result;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

4.json

@RequestBody 接收Json格式的数据需要加这个注解。该注解不能接收URL、Form表单传参

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 测试接收json数据
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/jsonData", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     public String jsonData(@RequestBody TestModel tm){
    
    
   
   


   
   
   
   

    
    

     
             String result = 
     
     "receive name = "+tm.getName()+
     
     " age = "+tm.getAge();
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(result);
    
    
   
   


   
   
   
   

    
    
        
     
     return result;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

5.@RequestMapping注解详细介绍

1.处理多个URL

 
 


   
   
   
   

    
    

     
     @RestController  
    
    
   
   


   
   
   
   

    
    

     
     @RequestMapping(
     
     "/home")  
    
    
   
   


   
   
   
   

    
    

     
     public 
     
     class IndexController {  
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = {  
    
    
   
   


   
   
   
   

    
    
        
     
     "",  
    
    
   
   


   
   
   
   

    
    
        
     
     "/page",  
    
    
   
   


   
   
   
   

    
    
        
     
     "page*",  
    
    
   
   


   
   
   
   

    
    
        
     
     "view/*,**/msg"  
    
    
   
   


   
   
   
   

    
    

     
         })  
    
    
   
   


   
   
   
   

    
    
    
     
     String indexMultipleMapping() {  
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "Hello from index multiple mapping.";  
    
    
   
   


   
   
   
   

    
    

     
         }  
    
    
   
   


   
   
   
   

    
    

     
     } 
    
    
   
   


 
 

这些 URL 都会由 indexMultipleMapping() 来处理： 

localhost:8080/home

localhost:8080/home/

localhost:8080/home/page

localhost:8080/home/pageabc

localhost:8080/home/view/

localhost:8080/home/view/view

2.HTTP的各种方法

如POST方法

@RequestMapping(value = "/test1", method = RequestMethod.POST)

3.produces、consumes 

produces 指定返回的内容类型，仅当request请求头header中的(Accept)类型中包含该指定类型才返回。结合@ResponseBody使用

 
 


   
   
   
   

    
    

     
     @Controller
    
    
   
   


   
   
   
   

    
    

     
     @RequestMapping(value = 
     
     "/t")
    
    
   
   


   
   
   
   

    
    

     
     public 
     
     class TestController {
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     //方法仅处理request请求中Accept头中包含了"text/html"的请求
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/produces",produces = {
     
     "text/html"})
    
    
   
   


   
   
   
   

    
    
    
     
     public String testProduces(String name)
    
    
   
   


   
   
   
   

    
    

     
         {
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "test requestMapping produces attribute! "+name;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    

     
     }
    
    
   
   


 
 

方法仅处理request请求中Accept头中包含了"text/html"的请求

比如用postman构建一个Accept=“application/json”的请求，请求会失败

comsumes  指定处理请求的提交内容类型（Content-Type），例如application/json, text/html。结合@RequestBody使用

 
 


   
   
   
   

    
    

     
     @Controller
    
    
   
   


   
   
   
   

    
    

     
     @RequestMapping(value = 
     
     "/t")
    
    
   
   


   
   
   
   

    
    

     
     public 
     
     class TestController {
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     //方法仅处理request Content-Type为"application/json"类型的请求
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/consumes",consumes = {
     
     "application/json"})
    
    
   
   


   
   
   
   

    
    
    
     
     public String testConsumes(@RequestBody String name)
    
    
   
   


   
   
   
   

    
    

     
         {
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "test requestMapping consumes attribute! "+name;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    

     
     }
    
    
   
   


 
 

方法仅处理request Content-Type为"application/json"类型的请求。

如果用postman构建一个Content-Type=“application/x-www-form-urlencoded”的请求，该方法不处理

4.headers 

根据请求中的消息头内容缩小请求映射的范围

例如：

只处理header中testHeader = sid的请求

 
 


   
   
   
   

    
    
    
     
     //方法仅处理header中testHeader = sid的请求
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/header",headers = {
     
     "testHeader = sid"})
    
    
   
   


   
   
   
   

    
    
    
     
     public String testHeader(String name)
    
    
   
   


   
   
   
   

    
    

     
         {
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "test requestMapping headers attribute! "+name;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

构建一个header钟不带testHeader=sid的请求，会失败

 

必须要header中带testHeader=sid的请求的请求才处理

5.结合params属性处理请求参数

例如：

请求参数name=sid的时候由getParams方法处理

请求参数name=lee的时候由getParamsDifferent方法处理

 
 


   
   
   
   

    
    

     
     @Controller
    
    
   
   


   
   
   
   

    
    

     
     @RequestMapping(value = 
     
     "/t")
    
    
   
   


   
   
   
   

    
    

     
     public 
     
     class TestController {
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/params", params = {
    
    
   
   


   
   
   
   

    
    
            
     
     "name=sid"
    
    
   
   


   
   
   
   

    
    

     
         })
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public String getParams(@RequestParam("name") String name) {
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "getParams method do " + name;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/params", params = {
    
    
   
   


   
   
   
   

    
    
            
     
     "name=lee"
    
    
   
   


   
   
   
   

    
    

     
         })
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public String getParamsDifferent(@RequestParam("name") String name) {
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     "getParamsDifferent method do  " + name;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    

     
     }
    
    
   
   


 
 

 

二、返回值

@RestController注解，相当于@Controller+@ResponseBody两个注解的结合，返回json数据不需要在方法前面加@ResponseBody注解了，但使用@RestController这个注解，就不能返回jsp,html页面，视图解析器无法解析jsp,html页面

1.返回静态html页面

application.yml

 
 


   
   
   
   

    
    

     
     server:
    
    
   
   


   
   
   
   

    
    

     
       port: 8088
    
    
   
   


   
   
   
   

    
    

     
       servlet:
    
    
   
   


   
   
   
   

    
    

     
         context-path: /sid
    
    
   
   


   
   
   
   


   
   
   
   

    
    

     
     spring:
    
    
   
   


   
   
   
   

    
    

     
       mvc:
    
    
   
   


   
   
   
   

    
    

     
        view:
    
    
   
   


   
   
   
   

    
    

     
         prefix: /
    
    
   
   


   
   
   
   

    
    

     
         suffix: .html
    
    
   
   


   
   
   
   


   
   
   
   


   
   
   
   


 
 

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 返回界面 index.html
    
    
   
   


   
   
   
   

    
    

     
          * @Controller修饰的类 直接定义方法返回值为String
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/index")
    
    
   
   


   
   
   
   

    
    
    
     
     public String index(){
    
    
   
   


   
   
   
   


   
   
   
   

    
    
        
     
     return 
     
     "index";
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     /**返回界面 index.html
    
    
   
   


   
   
   
   

    
    

     
          * @RestController修饰的类  
    
    
   
   


   
   
   
   

    
    

     
          * 需要配合视图解析器    
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(
     
     "/indexmv")
    
    
   
   


   
   
   
   

    
    
    
     
     public ModelAndView indexmv() {
    
    
   
   


   
   
   
   

    
    

     
             ModelAndView mv = 
     
     new ModelAndView(
     
     "index");
    
    
   
   


   
   
   
   

    
    
        
     
     return mv;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

2.通过object返回查询结果

@ResponseBody会把返回值变成json

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 直接查询得到的model类，@ResponseBody会把返回值变成json
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/object", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public Object object(@RequestParam("name") String name , @RequestParam("age") String age){
    
    
   
   


   
   
   
   


   
   
   
   

    
    

     
             TestModel t =getModel( name , age);
    
    
   
   


   
   
   
   

    
    

     
             List<TestModel> list =
     
     new ArrayList();
    
    
   
   


   
   
   
   

    
    

     
             list.add(t);
    
    
   
   


   
   
   
   

    
    
        
     
     return list;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

3.返回时直接抛出自定义异常

 
 


   
   
   
   

    
    
    
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 返回时直接抛出自定义异常
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/list", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public List<TestModel> list(@RequestParam("name") String name , @RequestParam("age") String age){
    
    
   
   


   
   
   
   

    
    

     
             TestModel t =getModel( name , age);
    
    
   
   


   
   
   
   


   
   
   
   

    
    
        
     
     if(t != 
     
     null){
    
    
   
   


   
   
   
   

    
    
            
     
     throw 
     
     new MyException(
     
     "测试抛出自定义异常");
    
    
   
   


   
   
   
   

    
    

     
             }
    
    
   
   


   
   
   
   

    
    

     
             List<TestModel> list =
     
     new ArrayList();
    
    
   
   


   
   
   
   

    
    

     
             list.add(t);
    
    
   
   


   
   
   
   

    
    

     
             list.add(t);
    
    
   
   


   
   
   
   

    
    
        
     
     return list;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

4.返回ResponseEntity

两种不同的创建ResponseEntity的方式

 
 


   
   
   
   

    
    
 
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 返回ResponseEntity
    
    
   
   


   
   
   
   

    
    

     
          *
    
    
   
   


   
   
   
   

    
    

     
          * ResponseEntity的优先级高于@ResponseBody。
    
    
   
   


   
   
   
   

    
    

     
          * 在不是ResponseEntity的情况下才去检查有没有@ResponseBody注解。
    
    
   
   


   
   
   
   

    
    

     
          * 如果响应类型是ResponseEntity可以不写@ResponseBody注解
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/responseEntity", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     public ResponseEntity<?> responseEntity(
     
     @RequestParam(
     
     "name") String name , 
     
     @RequestParam(
     
     "age") String age){
    
    
   
   


   
   
   
   


   
   
   
   

    
    
        
     
     try{
    
    
   
   


   
   
   
   

    
    

     
                 TestModel t =getModel( name , age);
    
    
   
   


   
   
   
   

    
    
            
     
     if(!t.getAge().equals(
     
     "27")){
    
    
   
   


   
   
   
   

    
    
                
     
     throw 
     
     new MyException(
     
     "年龄错误！");
    
    
   
   


   
   
   
   

    
    

     
                 }
    
    
   
   


   
   
   
   

    
    

     
                 List<TestModel> list =
     
     new ArrayList();
    
    
   
   


   
   
   
   

    
    

     
                 list.add(t);
    
    
   
   


   
   
   
   

    
    

     
                 list.add(t);
    
    
   
   


   
   
   
   

    
    

     
                 HttpHeaders headers = 
     
     new HttpHeaders();
    
    
   
   


   
   
   
   

    
    
            
     
     //headers.set("Content-type", "application/json;charset=UTF-8");
    
    
   
   


   
   
   
   

    
    

     
                 headers.add(
     
     "code", 
     
     "1");
    
    
   
   


   
   
   
   

    
    

     
                 headers.add(
     
     "msg", 
     
     "success");
    
    
   
   


   
   
   
   

    
    

     
                 headers.add(
     
     "error", 
     
     "");
    
    
   
   


   
   
   
   

    
    
            
     
     return 
     
     new ResponseEntity<List>(list,headers,HttpStatus.OK);
    
    
   
   


   
   
   
   

    
    

     
             }
     
     catch (MyException e){
    
    
   
   


   
   
   
   

    
    
            
     
     return ResponseEntity.badRequest()
    
    
   
   


   
   
   
   

    
    
                    
     
     //.header("Content-type", "application/json;charset=UTF-8")
    
    
   
   


   
   
   
   

    
    

     
                         .header(
     
     "code", 
     
     "0")
    
    
   
   


   
   
   
   

    
    

     
                         .header(
     
     "msg", 
     
     "")
    
    
   
   


   
   
   
   

    
    

     
                         .header(
     
     "error", e.getMessage())
     
     //中文乱码
    
    
   
   


   
   
   
   

    
    

     
                         .build();
     
     //build无返回值 body有返回值
    
    
   
   


   
   
   
   

    
    

     
             }
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

5.返回自定义类，其中有code msg error data 而查询结果在data中

MyResponse.java

 
 


   
   
   
   

    
    

     
     package com.sid.springtboot.test.springboottest;
    
    
   
   


   
   
   
   


   
   
   
   

    
    

     
     public 
     
     class MyResponse<T> {
    
    
   
   


   
   
   
   

    
    
    
     
     private String code;
    
    
   
   


   
   
   
   

    
    
    
     
     private String msg;
    
    
   
   


   
   
   
   

    
    
    
     
     private String error;
    
    
   
   


   
   
   
   

    
    
    
     
     private T data;
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public MyResponse(String code, String msg, String error, T data) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.code = code;
    
    
   
   


   
   
   
   

    
    
        
     
     this.msg = msg;
    
    
   
   


   
   
   
   

    
    
        
     
     this.error = error;
    
    
   
   


   
   
   
   

    
    
        
     
     this.data = data;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public String getCode() {
    
    
   
   


   
   
   
   

    
    
        
     
     return code;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setCode(String code) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.code = code;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public String getMsg() {
    
    
   
   


   
   
   
   

    
    
        
     
     return msg;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setMsg(String msg) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.msg = msg;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public String getError() {
    
    
   
   


   
   
   
   

    
    
        
     
     return error;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setError(String error) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.error = error;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public T getData() {
    
    
   
   


   
   
   
   

    
    
        
     
     return data;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setData(T data) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.data = data;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    

     
     }
    
    
   
   


 
 

MyException.java
 
 

 
 


   
   
   
   

    
    

     
     package com.sid.springtboot.test.springboottest;
    
    
   
   


   
   
   
   


   
   
   
   

    
    

     
     public 
     
     class MyException extends RuntimeException{
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     private String errorCode;
    
    
   
   


   
   
   
   

    
    
    
     
     private String msg;
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public MyException(String message) {
    
    
   
   


   
   
   
   

    
    
        
     
     super(message);
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public MyException(String errorCode, String msg) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.errorCode = errorCode;
    
    
   
   


   
   
   
   

    
    
        
     
     this.msg = msg;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public String getErrorCode() {
    
    
   
   


   
   
   
   

    
    
        
     
     return errorCode;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setErrorCode(String errorCode) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.errorCode = errorCode;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public String getMsg() {
    
    
   
   


   
   
   
   

    
    
        
     
     return msg;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   


   
   
   
   

    
    
    
     
     public void setMsg(String msg) {
    
    
   
   


   
   
   
   

    
    
        
     
     this.msg = msg;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


   
   
   
   

    
    

     
     }
    
    
   
   


 
 

 controller

 
 


   
   
   
   

    
    
 
     
     /**
    
    
   
   


   
   
   
   

    
    

     
          * 返回自定义类，其中有code msg error data 而查询结果在data中
    
    
   
   


   
   
   
   

    
    

     
          * */
    
    
   
   


   
   
   
   

    
    
    
     
     @RequestMapping(value = 
     
     "/myResponse", method = RequestMethod.POST)
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public MyResponse<?> myResponse(
     
     @RequestParam(
     
     "name") String name , 
     
     @RequestParam(
     
     "age") String age){
    
    
   
   


   
   
   
   

    
    
        
     
     try{
    
    
   
   


   
   
   
   

    
    

     
                 TestModel t1 =getModel( name , age);
    
    
   
   


   
   
   
   

    
    
            
     
     if(!t1.getAge().equals(
     
     "27")){
    
    
   
   


   
   
   
   

    
    
                
     
     throw 
     
     new MyException(
     
     "年龄错误！");
    
    
   
   


   
   
   
   

    
    

     
                 }
    
    
   
   


   
   
   
   

    
    

     
                 List<TestModel> list =
     
     new ArrayList();
    
    
   
   


   
   
   
   

    
    

     
                 list.add(t1);
    
    
   
   


   
   
   
   

    
    

     
                 list.add(t1);
    
    
   
   


   
   
   
   

    
    

     
                 list.add(t1);
    
    
   
   


   
   
   
   

    
    
            
     
     return 
     
     new MyResponse<List>(
     
     "1",
     
     "success",
     
     null,list);
    
    
   
   


   
   
   
   

    
    

     
             }
     
     catch (MyException e){
    
    
   
   


   
   
   
   

    
    
            
     
     return 
     
     new MyResponse<>(
     
     "0",
     
     null,e.getMessage(),
     
     null);
    
    
   
   


   
   
   
   

    
    

     
             }
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

三、上传、下载文件

上传文件

 
 


   
   
   
   

    
    
    
     
     @PostMapping(
     
     "/upload")
    
    
   
   


   
   
   
   

    
    
    
     
     @ResponseBody
    
    
   
   


   
   
   
   

    
    
    
     
     public Map<String, String> upload1(@RequestParam("file") MultipartFile file) throws IOException {
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(
     
     "[文件类型] - [{}]"+ file.getContentType());
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(
     
     "[文件名称] - [{}]"+ file.getOriginalFilename());
    
    
   
   


   
   
   
   

    
    

     
             System.out.println(
     
     "[文件大小] - [{}]"+ file.getSize());
    
    
   
   


   
   
   
   

    
    
        
     
     //保存
    
    
   
   


   
   
   
   

    
    

     
             file.transferTo(
     
     new File(
     
     "D:\\gitrep\\springboot\\testFile\\" + file.getOriginalFilename()));
    
    
   
   


   
   
   
   

    
    

     
             Map<String, String> result = 
     
     new HashMap<>(
     
     16);
    
    
   
   


   
   
   
   

    
    

     
             result.put(
     
     "contentType", file.getContentType());
    
    
   
   


   
   
   
   

    
    

     
             result.put(
     
     "fileName", file.getOriginalFilename());
    
    
   
   


   
   
   
   

    
    

     
             result.put(
     
     "fileSize", file.getSize() + 
     
     "");
    
    
   
   


   
   
   
   

    
    
        
     
     return result;
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

下载文件

1.通过ResponseEntity<InputStreamResource>实现

封装ResponseEntity，将文件流写入body中。这里注意一点，就是文件的格式需要根据具体文件的类型来设置，一般默认为application/octet-stream。文件头中设置缓存，以及文件的名字。文件的名字写入了，都可以避免出现文件随机产生名字，而不能识别的问题。

 
 


   
   
   
   

    
    

     
     @GetMapping(
     
     "/download")
    
    
   
   


   
   
   
   

    
    
    
     
     public ResponseEntity<InputStreamResource> downloadFile() throws IOException {
    
    
   
   


   
   
   
   

    
    

     
             String filePath = 
     
     "D:\\gitrep\\springboot\\testFile\\" + 
     
     "api-ms-win-core-console-l1-1-0.dll";
    
    
   
   


   
   
   
   

    
    

     
             FileSystemResource file = 
     
     new FileSystemResource(filePath);
    
    
   
   


   
   
   
   

    
    

     
             HttpHeaders headers = 
     
     new HttpHeaders();
    
    
   
   


   
   
   
   

    
    

     
             headers.add(
     
     "Cache-Control", 
     
     "no-cache, no-store, must-revalidate");
    
    
   
   


   
   
   
   

    
    

     
             headers.add(
     
     "Content-Disposition", String.format(
     
     "attachment; filename=\"%s\"", file.getFilename()));
    
    
   
   


   
   
   
   

    
    

     
             headers.add(
     
     "Pragma", 
     
     "no-cache");
    
    
   
   


   
   
   
   

    
    

     
             headers.add(
     
     "Expires", 
     
     "0");
    
    
   
   


   
   
   
   


   
   
   
   

    
    
        
     
     return ResponseEntity.ok().headers(headers)
    
    
   
   


   
   
   
   

    
    

     
                     .contentLength(file.contentLength())
    
    
   
   


   
   
   
   

    
    

     
                     .contentType(MediaType.parseMediaType(
     
     "application/octet-stream"))
    
    
   
   


   
   
   
   

    
    

     
                     .body(
     
     new InputStreamResource(file.getInputStream()));
    
    
   
   


   
   
   
   

    
    

     
         }
    
    
   
   


 
 

2.用HttpServletResponse

 
 


   
   
   
   

    
    

     
     @GetMapping(
     
     "/download2")
    
    
   
   


   
   
   
   

    
    
    
     
     public String downloadFile2( HttpServletResponse response) throws IOException {
    
    
   
   


   
   
   
   

    
    
        
     
     // 获取指定目录下的文件
    
    
   
   


   
   
   
   

    
    

     
             String fileName = 
     
     "D:\\gitrep\\springboot\\testFile\\" + 
     
     "api-ms-win-core-console-l1-1-0.dll";
    
    
   
   


   
   
   
   

    
    

     
             File file = 
     
     new File(fileName);
    
    
   
   


   
   
   
   

    
    
        
     
     // 如果文件名存在，则进行下载
    
    
   
   


   
   
   
   

    
    
        
     
     if (file.exists()) {
    
    
   
   


   
   
   
   

    
    
            
     
     // 配置文件下载
    
    
   
   


   
   
   
   

    
    

     
                 response.setHeader(
     
     "content-type", 
     
     "application/octet-stream");
    
    
   
   


   
   
   
   

    
    

     
                 response.setContentType(
     
     "application/octet-stream");
    
    
   
   


   
   
   
   

    
    
            
     
     // 下载文件能正常显示中文
    
    
   
   


   
   
   
   

    
    

     
                 response.setHeader(
     
     "Content-Disposition", 
     
     "attachment;filename=" + URLEncoder.encode(fileName, 
     
     "UTF-8"));
    
    
   
   


   
   
   
   


   
   
   
   

    
    
            
     
     // 实现文件下载
    
    
   
   


   
   
   
   

    
    
            
     
     byte[] buffer = 
     
     new 
     
     byte[
     
     1024];
    
    
   
   


   
   
   
   

    
    

     
                 FileInputStream fis = 
     
     null;
    
    
   
   


   
   
   
   

    
    

     
                 BufferedInputStream bis = 
     
     null;
    
    
   
   


   
   
   
   

    
    
            
     
     try {
    
    
   
   


   
   
   
   

    
    

     
                     fis = 
     
     new FileInputStream(file);
    
    
   
   


   
   
   
   

    
    

     
                     bis = 
     
     new BufferedInputStream(fis);
    
    
   
   


   
   
   
   

    
    

     
                     OutputStream os = response.getOutputStream();
    
    
   
   


   
   
   
   

    
    
                
     
     int i = bis.read(buffer);
    
    
   
   


   
   
   
   

    
    
                
     
     while (i != -
     
     1) {
    
    
   
   


   
   
   
   

    
    

     
                         os.write(buffer, 
     
     0, i);
    
    
   
   


   
   
   
   

    
    

     
                         i = bis.read(buffer);
    
    
   
   


   
   
   
   

    
    

     
                     }
    
    
   
   


   
   
   
   

    
    

     
                     System.out.println(
     
     "Download the song successfully!");
    
    
   
   


   
   
   
   

    
    

     
                 }
    
    
   
   


   
   
   
   

    
    
            
     
     catch (Exception e) {
    
    
   
   


   
   
   
   

    
    

     
                     System.out.println(
     
     "Download the song failed!");
    
    
   
   


   
   
   
   

    
    

     
                 } 
     
     finally {
    
    
   
   


   
   
   
   

    
    
                
     
     if (bis != 
     
     null) {
    
    
   
   


   
   
   
   

    
    
                    
     
     try {
    
    
   
   


   
   
   
   

    
    

     
                             bis.close();
    
    
   
   


   
   
   
   

    
    

     
                         } 
     
     catch (IOException e) {
    
    
   
   


   
   
   
   

    
    

     
                             e.printStackTrace();
    
    
   
   


   
   
   
   

    
    

     
                         }
    
    
   
   


   
   
   
   

    
    

     
                     }
    
    
   
   


   
   
   
   

    
    
                
     
     if (fis != 
     
     null) {
    
    
   
   


   
   
   
   

    
    
                    
     
     try {
    
    
   
   


   
   
   
   

    
    

     
                             fis.close();
    
    
   
   


   
   
   
   

    
    

     
                         } 
     
     catch (IOException e) {
    
    
   
   


   
   
   
   

    
    

     
                             e.printStackTrace();
    
    
   
   


   
   
   
   

    
    

     
                         }
    
    
   
   


   
   
   
   

    
    

     
                     }
    
    
   
   


   
   
   
   

    
    

     
                 }
    
    
   
   


   
   
   
   

    
    

     
             }
    
    
   
   


   
   
   
   

    
    
        
     
     return 
     
     null;
    
    
   
   


   
   
   
   

    
    

     
         }