1、引入maven依賴（版本太低也會導致不生效）

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-validation</artifactId><version>2.7.10</version></dependency>

2、創建注解接口（javax.validation版本是2.0.0的，自行選擇，太低也不行）

package com.wang.test.annotation;
import com.wang.test.annotation.CheckField.List;import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.*;import static java.lang.annotation.ElementType.*;
//主要標記在什么代碼上可以使用
//    TYPE,//類，接口（包括注解類型）或枚舉的聲明
//    FIELD,//屬性的聲明
//    METHOD,//方法的聲明
//    PARAMETER,//方法形式參數聲明
//    CONSTRUCTOR,//構造方法的聲明
//    LOCAL_VARIABLE,//局部變量聲明
//    ANNOTATION_TYPE,//注解類型聲明
//    PACKAGE//包的聲明
@Target({METHOD,FIELD,ANNOTATION_TYPE,CONSTRUCTOR,PARAMETER,TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(List.class)
//CheckValidator  自定義類，主要用于注解校驗
@Constraint(validatedBy = CheckValidator.class)
public @interface CheckField {String message() default "密碼必須包含至少一個大寫字母、一個小寫字母和一個數字";Class<?>[] groups() default {};Class<? extends Payload>[] payload() default {};@Target({METHOD,FIELD,ANNOTATION_TYPE,CONSTRUCTOR,PARAMETER,TYPE_USE})@Retention(RetentionPolicy.RUNTIME)@Documented@interface List {CheckField[] value();}
}

package com.wang.test.annotation;import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;//CheckField  自定義注解的接口
public class CheckValidator implements ConstraintValidator<CheckField, String> {private static final String PASSWORD_PATTERN = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)[a-zA-Z\\d]{8,}$";@Overridepublic void initialize(CheckField constraintAnnotation) {}@Overridepublic boolean isValid(String value, ConstraintValidatorContext context) {
//        if (!value.matches(PASSWORD_PATTERN)) {
//            throw new RuntimeException("大大");
//        }
//        return value.matches(PASSWORD_PATTERN);if (value.contains("*")){throw new RuntimeException("包含");}else {return true;}}
}

3、可以創建全局異常來捕獲（Result可以自己定義）

package com.wang.test.annotation;import com.wang.test.utils.Result;
import lombok.extern.slf4j.Slf4j;
import org.omg.CORBA.SystemException;
import org.springframework.validation.BindException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {@ExceptionHandler(SystemException.class)public Result systemExceptionHandler(SystemException e) {log.error("出現了異常! {}", e);return Result.nok(e.getCause().getMessage());}@ExceptionHandler(Exception.class)public Result exceptionHandler(Exception e) {log.error("出現了異常! {}", e);return Result.nok(e.getCause().getMessage());}/* 添加校驗參數異常處理 */@ExceptionHandler(BindException.class)public Result bindExceptionHandler(BindException e) {log.error("出現了異常! {}", e);return Result.nok(e.getCause().getMessage());}
}

4、統一返回結果類

package com.wang.test.utils;public class Result<T> {private static final String SUCCESS = "SUCCESS";private static final String FAIL = "FAIL";private String code;private String message;private T Data;public Result(String code) {this.code = code;}public Result(String code, String message) {super();this.code = code;this.message = message;}public Result(String code, String message, T data) {super();this.code = code;this.message = message;Data = data;}public Result() {}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}public T getData() {return Data;}public void setData(T data) {Data = data;}public static <T> Result<T> ok(T object) {return new Result<T>(SUCCESS, "", object);}public static <T> Result<T> ok() {return new Result<T>(SUCCESS);}public static <T> Result<T> nok(String message) {return new Result<T>(FAIL, message);}public static <T> Result<T> nok() {return new Result<T>(FAIL);}public static <T> Result<T> nok(String code, String message) {return new Result<T>(code, message);}public static <T> Result<T> nok(String code, String message, T object) {return new Result<T>(code, message, object);}
}

5、場景使用

package com.wang.test.entity;import com.alibaba.excel.annotation.ExcelIgnore;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.annotation.format.NumberFormat;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.wang.test.annotation.CheckField;
import com.wang.test.utils.CustomStringStringConverter;
import lombok.*;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.validation.annotation.Validated;import javax.validation.Valid;
import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;
import java.util.List;@Data
@EqualsAndHashCode(callSuper = false)
//@Accessors(chain = true)
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class WaterMeter implements Serializable {/**@CheckField(message = "dadad")@TableField("waterMeter")@ExcelProperty(value = {"水表數據","水表名"},converter = CustomStringStringConverter.class)private String waterMeter;private List<@Valid uesr> uesrList;
}package com.wang.test.entity;import com.wang.test.annotation.CheckField;
import lombok.Data;
import lombok.EqualsAndHashCode;/*** @BelongsPackage: com.wang.test.entity* @Author: wangqian* @CreateTime: 2023-08-08  09:15:59* @Describe:*/
@Data
@EqualsAndHashCode(callSuper = false)
public class uesr {String id;@CheckField()String age;}//這個是接口，需要在接口傳參上加@Validated 注解，
//注解版本（org.springframework:spring-context:5.3.26）
@PostMapping("/getDataById")public Result a(@Validated @RequestBody WaterMeter waterMeter){
//        WaterMeter waterMeter = waterMeterService.getDataById(id);return Result.ok(waterMeter);}