三个常用注解:

  @RequestParam、@RequestBody、 @PathVariable、

1.@RequestParam:将请求参数绑定到你控制器的方法参数上(是springmvc中接收普通参数的注解)

 例如:URL:localhost:8080/del?id=3

@ResponseBody
    @GetMapping("/del")
    public String deleteUserByIdOneContorller(@RequestParam("id") int id){
        boolean resulte = userService.deleteUserByIdOne(id);
        if (resulte){
            return "删除成功";
        }
        return "删除失败!";
    }

2.@PathVariable可以用来映射URL中的占位符到目标方法的参数中

 例如:URL:localhost:8080/findSpecsByPhoneId/3

@GetMapping("/findSpecsByPhoneId/{phoneId}")
    public ResultVO findSpecsByPhoneId(@PathVariable("phoneId") Integer phoneId){
        return ResultVOUtil.success(phoneService.findSpecsByPhoneId(phoneId));

    }

3、通过HttpServletRequest接收,post方式和get方式都可以。

@RequestMapping("/addUser2")
    public String addUser2(HttpServletRequest request) {
        String username=request.getParameter("username");
        String password=request.getParameter("password");
        System.out.println("username is:"+username);
        System.out.println("password is:"+password);
        return "demo/index";
    }

4. 用注解@RequestBody绑定请求参数到方法入参  用于POST请求,UserDTO 这个类为一个实体类,里面定义的属性与URL传过来的属性名一一对应。

@RequestMapping(value="/addUser6",method=RequestMethod.POST)
    public String addUser6(@RequestBody UserDTO userDTO) {
        System.out.println("username is:"+userDTO.getUserName());
        System.out.println("password is:"+userDTO.getPassWord());
        return "demo/index";
    }

5.直接把表单的参数写在Controller相应的方法的形参中,提交的参数需要和Controller方法中的入参名称一致。

例如:URL:http://localhost/SSMDemo/demo/addUser1?username=lixiaoxi&password=111111

public String addUser1(String username,String password) {
        System.out.println("username is:"+username);
        System.out.println("password is:"+password);
        return "demo/index";
    }

6.通过一个bean来接收,post方式和get方式都可以。

(1)建立一个和表单中参数对应的bean

public class UserModel {
    
    private String username;
    private String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
}

(2)用这个bean来封装接收的参数

@RequestMapping("/addUser3")
    public String addUser3(UserModel user) {
        System.out.println("username is:"+user.getUsername());
        System.out.println("password is:"+user.getPassword());
        return "demo/index";
    }

7.使用@ModelAttribute