@RequestMapping @PathVariable @ResponseBody @RequestParam的区别

左手的ㄟ右手 2022-05-31 06:20 220阅读 0赞

**@RequestMappingis used to map web requests onto specific handler classes and/or handler methods.**

**例如：**

1.  @RequestMapping with Class
    
        @Controller
        @RequestMapping("/home")
        public class HomeController {
             
        
        }
2.  @RequestMapping with Method
    
        @RequestMapping(value="/method0")
        @ResponseBody
        public String method0(){
             
        	return "method0";
        }
3.  @RequestMapping with Multiple URI: We can use a single method for handling multiple URIs, for example:
    
        @RequestMapping(value={
             "/method1","/method1/second"})
        @ResponseBody
        public String method1(){
             
        	return "method1";
        }
4.  @RequestMapping with HTTP Method
    
        @RequestMapping(value="/method2", method=RequestMethod.POST)
        @ResponseBody
        public String method2(){
             
        	return "method2";
        }
        	
        @RequestMapping(value="/method3", method={
             RequestMethod.POST,RequestMethod.GET})
        @ResponseBody
        public String method3(){
             
        	return "method3";
        }
5.  @RequestMapping with Headers
    
        @RequestMapping(value="/method4", headers="name=pankaj")
        @ResponseBody
        public String method4(){
             
        	return "method4";
        }
        	
        @RequestMapping(value="/method5", headers={
             "name=pankaj", "id=1"})
        @ResponseBody
        public String method5(){
             
        	return "method5";
        }
6.  @RequestMapping with Produces and Consumes
    
    consumes： 指定处理请求的提交内容类型（Content-Type），例如application/json, text/html
    
    produces: 指定返回的内容类型，仅当request请求头中的(Accept)类型中包含该指定类型才返回
    
        @RequestMapping(value="/method6", produces={
             "application/json","application/xml"}, consumes="text/html")
        @ResponseBody
        public String method6(){
             
        	return "method6";
        }

**@PathVariable can be used to handle dynamic URIs where one or more of the URI value works as a parameter.**

@RequestMapping(value="/method7/{id}")
    @ResponseBody
    public String method7(@PathVariable("id") int id){
        
    	return "method7 with id="+id;
    }
    	
    @RequestMapping(value="/method8/{id:[\\d]+}/{name}")
    @ResponseBody
    public String method8(@PathVariable("id") long id, @PathVariable("name") String name){
        
    	return "method8 with id= "+id+" and name="+name;
    }

**@ResponseBody** 将controller的方法返回的对象通过适当的转换器转换为指定的格式之后，写入到response对象的body区，通常用来返回JSON数据或者是XML

@RequestMapping("/login")  
　　@ResponseBody  
　　public User login(User user)\{  
　　　　return user;  
　　\}  
　　User字段：username password  
　　那么在前台接收到的数据为：'\{"username":"xxx","password":"xxx"\}'  
  
　　效果等同于如下代码：  
　　@RequestMapping("/login")  
　　public void login(User user, HttpServletResponse response)\{  
　　　　response.getWriter.write(JSONObject.fromObject(user).toString());  
　　\}

**@RequestParam**

get 方式中queryString的值，和post方式中 body data的值都会被Servlet接受到并转化到Request.getParameter()参数集中，所以@RequestParam可以获取的到。

形如：

@RequestMapping("/user")

public void getUser(@RequestParam("username") String username) \{

这里获取的数据形如：

http://localhost:8080/com/wyd/controller/user?name=wyd

1.  <form action="/com/wyd/controller/user" method="get">  
    username:<input type="text" name="username">  
    password:<input type="text" name="password">  
    <input type="submit" value="submit">  
    </form>
2.