关于@RequestBody和@RequestParam注解的使用详解

@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestParam {
    @AliasFor("name")
    String value() default "";
 
    @AliasFor("value")
    String name() default "";
 
    boolean required() default true;
 
    String defaultValue() default "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n";
}

  	@GetMapping("/hello")
    public String hello(@RequestParam(name = "id") Long id){
        System.out.println("hello " + id);
        return "hello message";
    }

	@PostMapping("/save")
    public String hello(@RequestParam(name = "id") Long id,
                        @RequestParam("name") String name,
        				@RequestParam("password") String password){
   		System.out.println(user);
        return "hello message";
    }

@Data
public class User {
 
    @NotNull(message = "id不能为空")
    private Long id;
 
    @NotBlank(message = "名字不能为空")
    private String name;
 
    @NotBlank(message = "密码不能为空")
    private String password;
}

// @RequestParam 不支持直接传递实体类的方式，所以可以在实体类中做数据校验，使用 @Validated 注解使得作用在实体类属性上的注解生效
@PostMapping("/save")
public String save(@Validated User user){
    System.out.println(user);
    return "hello success";
}
// console result: User(id=110, name=admin, password=123456)

// console result: User(id=null, name=null, password=null)

@PostMapping("/saveBatch")
public String saveBatch(@RequestBody @Validated List<User> list){
    list.forEach(System.out::println);
    return "saveBatch success";
}

// console result： 
// User(id=1, name=admin, password=123456)
// User(id=2, name=cheny, password=cheny)

@PostMapping("/listMap")
public String saveMap(@RequestBody List<Map<String, String>> listMap){
    for (Map<String, String> map : listMap) {
        System.out.println(map);
    }
    return "listMap success";
}

// console result：
// {id=1, name=admin}
// {id=2, age=18}