validation之自定义注解@Constraint

前言：

首先，接口参数校验应该都不陌生，大部分应该都会借助javax.validation进行快捷校验，一般都是在入参字段上添加@NotNull、@NotEmpty等，对于一些特殊的入参校验逻辑，可能不是很适用，现在介绍一下自定义注解方式。

依赖：

    <dependency><groupId>org.hibernate.validator</groupId><artifactId>hibernate-validator</artifactId><version>6.0.10.Final</version></dependency>

代码：

自定义注解：

import javax.validation.Constraint;
import javax.validation.Payload;import java.lang.annotation.*;@Target({ElementType.FIELD, ElementType.METHOD, ElementType.ANNOTATION_TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = {EnumValidator.class})
public @interface EnumValid {String message() default "";Class<?>[] groups() default {};Class<? extends Payload>[] payload() default {};/*** 目标枚举类*/Class<? extends Enum> target() default Enum.class;
}

实际校验类：

import com.honor.wpshowdemo.serverone.valid.EnumValid;
import org.apache.commons.lang.StringUtils;import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;public class EnumValidator implements ConstraintValidator<EnumValid, Object> {private EnumValid annotation;@Overridepublic void initialize(EnumValid constraintAnnotation) {annotation = constraintAnnotation;}@Overridepublic boolean isValid(Object value, ConstraintValidatorContext constraintValidatorContext) {boolean result = false;Class<?> cls = annotation.target();// target为枚举，并且value有值，才进行校验if (cls.isEnum() && (value != null)) {Object[] objects = cls.getEnumConstants();for (Object obj : objects) {//object类型转mapClass<?> jqlEnum = obj.getClass();Field[] fs = jqlEnum.getDeclaredFields();Map<String, String> objMap = new HashMap<>();for (Field f : fs) {f.setAccessible(true);try {objMap.put(f.getName(), f.get(obj).toString());} catch (IllegalArgumentException | IllegalAccessException e) {e.printStackTrace();}}if (objMap.get("code") != null && StringUtils.equals(objMap.get("code"), String.valueOf(value))) {result = true;break;}}}return result;}
}

测试：

测试代码：

import lombok.Getter;public enum TestEnum {FAILED(0),SUCCESS(1);@Getterprivate Integer id;TestEnum(Integer id) {this.id = id;}
}

import lombok.Data;@Data
public class TestRequest {@EnumValid(target = TestEnum.class, message = "id不符合要求")private Integer id;
}

import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;import javax.validation.Valid;@RestController
public class TestController {@PostMapping("/test")public void test(@RequestBody @Valid TestRequest testRequest) {}
}

测试结果如下：