157-Spring Boot中 @Valid无效的解决

spring boot项目，需要添加依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

controller类：

    @PostMapping("test1")
    public Object test1(@RequestBody @Valid User u){
        System.out.println("222");
        return "2";
    }

User类：

public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    private Long id;
    private String name;
    @NotNull(message = "不能为空")
    private String note;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }
}