1.引入依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
    <version>3.1.2</version>
</dependency>

2：实体类

实体类属性加上@NotNull注解  例：@NotNull(message = "id不能为空")

public class People  {
    private Integer bizCode;
    @NotNull(message = "id不能为空")
    private Long id;
    private String name;
    private Integer age;
    private String address;
    private String userName;
    private String pwd;
    private String email;
    private String phonenumber;
    private String sex;

    public Long getId() {
        return id;
    }

    public Integer getBizCode() {
        return bizCode;
    }

    public void setBizCode(Integer bizCode) {
        this.bizCode = bizCode;
    }

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

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhonenumber() {
        return phonenumber;
    }

    public void setPhonenumber(String phonenumber) {
        this.phonenumber = phonenumber;
    }

    @JsonIgnore
    @JsonProperty
    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

3：controller   加上@Valid 注解

@RestController
public class PeopleController {
    

    @PostMapping("save")
    public AjaxResult save(  @RequestBody  @Valid People people) {
        System.out.println(people);
        return AjaxResult.success( people );
    }
}

4：创建全局异常类，捕获异常

/**
 * 全局异常处理器
 */
@RestControllerAdvice
public class GlobalExceptionHandler
{
    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    /**
     * 自定义验证异常
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public Object handleMethodArgumentNotValidException(MethodArgumentNotValidException e)
    {
        log.error(e.getMessage(), e);
        String message = e.getBindingResult().getFieldError().getDefaultMessage();
        return AjaxResult.error(message);
    }


}

5：postman测试

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