自定义validation注解解决动态多字段联动校验问题

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　　javax.validation是基于JSR-303标准定义的一组接口，目的是使开发者简洁地校验参数，hibernate-validator实现了这一组接口，可以作为工具独立引用。     javax.validation     validation-api     1.1.0.Final       org.hibernate     hibernate-validator     6.0.18.Final 
　　如果是SpringBoot项目则无需显示引用上述依赖，因为SpringBoot已经将上述依赖进行了集成。
　　2 基本使用2.1 定义模型import java.math.BigDecimal; import java.util.List; import javax.validation.constraints.DecimalMin; import javax.validation.constraints.Max; import javax.validation.constraints.Min; import javax.validation.constraints.NotBlank; import javax.validation.constraints.Size; import lombok.Data;  @Data public class OrderModelA {      @Min(value = 1, message = ＂订单编号必须大于等于1＂)     @Max(value = 100, message = ＂订单编号必须小于等于100＂)     private Integer orderId;      @NotBlank(message = ＂订单名称不能为空＂)     private String orderName;      @Size(min = 1, max = 10)     private List goodsList;      @DecimalMin(value = ＂1＂, message = ＂订单金额必须大于等于1＂)     private BigDecimal amount; }
　　2.2 定义接口import javax.validation.Valid; import javax.validation.constraints.NotNull; import org.springframework.validation.annotation.Validated; import com.java.front.validation.model.OrderModelA;  @Validated public interface BizValidateService {      void bizMethodA(@Valid OrderModelA model, @NotNull String param); }
　　2.3 接口实现import javax.validation.Valid; import javax.validation.constraints.NotNull; import org.springframework.stereotype.Component; import com.alibaba.fastjson.JSON; import com.java.front.validation.model.OrderModelA;  @Component public class BizValidateServiceImpl implements BizValidateService {      @Override     public void bizMethodA(@Valid OrderModelA model, @NotNull String param) {         System.out.println(＂execute bizA model=＂ + JSON.toJSONString(model) + ＂,param=＂ + param);     } }
　　2.4 测试用例@RunWith(SpringRunner.class) @SpringBootTest public class TestAuthApplication {      @Autowired     private BizValidateService bizValidateService;      @Test     public void testBizValidateA_correct() {         OrderModelA model = new OrderModelA();         model.setOrderId(1);         model.setOrderName(＂订单名称＂);         List goodsList = new ArrayList();         goodsList.add(＂goods1＂);         goodsList.add(＂goods2＂);         goodsList.add(＂goods3＂);         model.setGoodsList(goodsList);         model.setAmount(new BigDecimal(＂10＂));         bizValidateService.bizMethodA(model, ＂param＂);     }      @Test     public void testBizValidateA_error() {         OrderModelA model = new OrderModelA();         model.setOrderId(0);         model.setOrderName(＂订单名称＂);         List goodsList = new ArrayList();         goodsList.add(＂goods1＂);         goodsList.add(＂goods2＂);         goodsList.add(＂goods3＂);         model.setGoodsList(goodsList);         model.setAmount(new BigDecimal(＂10＂));         bizValidateService.bizMethodA(model, ＂param＂);     } }
　　2.5 报错信息javax.validation.ConstraintViolationException: bizMethodA.model.orderId: 订单编号必须大于等于1 	at org.springframework.validation.beanvalidation.MethodValidationInterceptor.invoke(MethodValidationInterceptor.java:117) 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) 	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) 	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) 	at com.java.front.validation.BizValidateServiceImpl$EnhancerBySpringCGLIB$42c25c43.bizMethodA() 	at com.java.front.TestAuthApplication.testBizValidateA_error(TestAuthApplication.java:62)
　　3 复杂应用
　　现在我们假设一种场景订单新增了type1、type2两个字段，这两个字段影响对于orderId值范围判断，也就是说orderId范围判断不再是静态的，而是受其它字段影响。
　　针对这种情况第一步我们可以构造type1、type2、orderId组合字段，第二步自定义校验器将组合字段拆开进行业务校验。
　　3.1 定义注解import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import javax.validation.Constraint; import javax.validation.Payload;  @Documented @Retention(RetentionPolicy.RUNTIME) @Target({ ElementType.PARAMETER, ElementType.FIELD, ElementType.METHOD }) @Constraint(validatedBy = TypeAndOrderIdValidator.class) public @interface TypeAndOrderIdValid {      String message() default ＂不满足业务条件＂;      Class<?>[] groups() default {};      Class<? extends Payload>[] payload() default {}; }
　　3.2 定义校验器import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import com.java.front.validation.model.OrderModelB;  public class TypeAndOrderIdValidator implements ConstraintValidator {      @Override     public boolean isValid(String value, ConstraintValidatorContext context) {         String[] array = value.split(OrderModelB.JOINT);         int type1 = Integer.parseInt(array[0]);         int type2 = Integer.parseInt(array[1]);         int orderId = Integer.parseInt(array[2]);         if (type1 == 1 && type2 == 2) {             return orderId > 20;         }         return true;     } }
　　3.3 定义模型import java.math.BigDecimal; import java.util.List; import javax.validation.constraints.DecimalMin; import javax.validation.constraints.Max; import javax.validation.constraints.Min; import javax.validation.constraints.NotBlank; import javax.validation.constraints.Size; import com.alibaba.fastjson.annotation.JSONField; import com.java.front.server.validation.extend.TypeAndOrderIdValid; import lombok.Data;  @Data public class OrderModelB {     public static final String JOINT = ＂_＂;      @Min(value = 1, message = ＂订单编号必须大于等于1＂)     @Max(value = 100, message = ＂订单编号必须小于等于100＂)     private Integer orderId;      @NotBlank(message = ＂订单名称不能为空＂)     private String orderName;      @Size(min = 1, max = 10)     private List goodsList;      @DecimalMin(value = ＂1＂, message = ＂订单金额必须大于等于1＂)     private BigDecimal amount;      private int type1;      private int type2;      @JSONField(serialize = false)     private String typeAndOrderIdComposite;      @TypeAndOrderIdValid     public String getTypeAndOrderIdComposite() {         return getType1() + JOINT + getType2() + JOINT + getOrderId();     } }
　　3.4 定义接口import javax.validation.Valid; import javax.validation.constraints.NotNull; import org.springframework.validation.annotation.Validated; import com.java.front.validation.model.OrderModelB;  @Validated public interface BizValidateService {      void bizMethodB(@Valid OrderModelB model, @NotNull String param); }
　　3.5 接口实现import javax.validation.Valid; import javax.validation.constraints.NotNull; import org.springframework.stereotype.Component; import com.alibaba.fastjson.JSON; import com.java.front.server.validation.model.OrderModelB;  @Component public class BizValidateServiceImpl implements BizValidateService {      @Override     public void bizMethodB(@Valid OrderModelB model, @NotNull String param) {         System.out.println(＂execute bizB model=＂ + JSON.toJSONString(model) + ＂,param=＂ + param);     } }
　　3.6 测试用例@RunWith(SpringRunner.class) @SpringBootTest public class TestAuthApplication {      @Autowired     private BizValidateService bizValidateService;      @Test     public void testBizValidateB_correct() {         OrderModelB model = new OrderModelB();         model.setOrderId(30);         model.setOrderName(＂订单名称＂);         List goodsList = new ArrayList();         goodsList.add(＂goods1＂);         goodsList.add(＂goods2＂);         goodsList.add(＂goods3＂);         model.setGoodsList(goodsList);         model.setAmount(new BigDecimal(＂10＂));         model.setType1(1);         model.setType2(2);         bizValidateService.bizMethodB(model, ＂param＂);     }      @Test     public void testBizValidateB_error() {         OrderModelB model = new OrderModelB();         model.setOrderId(1);         model.setOrderName(＂订单名称＂);         List goodsList = new ArrayList();         goodsList.add(＂goods1＂);         goodsList.add(＂goods2＂);         goodsList.add(＂goods3＂);         model.setGoodsList(goodsList);         model.setAmount(new BigDecimal(＂10＂));         model.setType1(1);         model.setType2(2);         bizValidateService.bizMethodB(model, ＂param＂);     } }
　　3.7 错误信息javax.validation.ConstraintViolationException: bizMethodB.model.typeAndOrderIdComposite: 不满足业务条件 	at org.springframework.validation.beanvalidation.MethodValidationInterceptor.invoke(MethodValidationInterceptor.java:117) 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) 	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) 	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) 	at com.java.front.validation.BizValidateServiceImpl$EnhancerBySpringCGLIB$7c26a7cb.bizMethodB() 	at com.java.front.server.TestAuthApplication.testBizValidateB_error(TestAuthApplication.java:94)
　　4 文章总结
　　本文第一章节介绍了validation基本概念，第二章节介绍了validation基本应用，第三章节介绍了通过自定义注解动态校验字段，希望本文对大家有所帮助。
　　欢迎大家关注今日头条号「JAVA前线」查看更多精彩分享文章，主要包括源码分析、实际应用、架构思维、职场分享、产品思考