自定义注解实现@Valid利用枚举检验入参

自定义注解实现@Valid利用枚举检验入参

在实际业务中，会出现，入参会限制传参，比如id ,只能传1,2,通过id来判断业务类型，这时候，传入3就会报错，所以检验id是否在1,2中的逻辑，我们把他简化到入参检验中，也就是@Vaild

引入依赖pom

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

自定义注解

package com.example.demo0927;

import javax.validation.Constraint;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import javax.validation.Payload;
import java.lang.annotation.*;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

/**
 * @author liuxuewei
 */
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
@Constraint(validatedBy = EnumValidator.EnumValidatorHandle.class)
public @interface EnumValidator {
    Class<?> value();

    String message() default "参数错误";

    String method() default "getValue";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};


    class EnumValidatorHandle implements ConstraintValidator<EnumValidator, Object> {
        private List<Object> values = new ArrayList<>();

        @Override
        public void initialize(EnumValidator enumValidator) {
            Class<?> clz = enumValidator.value();
            Object[] objects = clz.getEnumConstants();

            try {
                Method method = clz.getMethod(enumValidator.method());
                if (Objects.isNull(method)) {
                    throw new RuntimeException(String.format("枚举对象%s缺少名为%s的方法", clz.getName(), enumValidator.method()));
                }
                Object value;
                for (Object obj : objects) {
                    value = method.invoke(obj);
                    values.add(value);
                }
            } catch (Exception e) {
                System.out.println(e.getMessage());
//                e.printStackTrace();
            }

        }

        @Override
        public boolean isValid(Object value, ConstraintValidatorContext constraintValidatorContext) {
            return Objects.isNull(value) || values.contains(value);
        }
    }
}

枚举类【限制业务类型】

package com.example.demo0927;

import lombok.AllArgsConstructor;
import lombok.Getter;

import java.util.Objects;

/**
 * @author liuxuewei
 */
@Getter
@AllArgsConstructor
public enum TestEnum{
    TTT(1,"是个1"),
    LLL(2,"是个2"),
    ;

    int code;
    String dec;

    public static String checkCode(int value) { //可以认为是有值，返回一个值，没有就返回null
        System.out.println("getValue=>");
        for (TestEnum testEnum : TestEnum.values()) {
            if (Objects.equals(value, testEnum.getCode())) {
                return testEnum.getDec();
            }
        }
        return null;
    }
}

入参对象

/**
 * @author liuxuewei
 */
@Data
public class TestRequest implements Serializable {

    @EnumValidator(value = TestEnum.class, method = "checkCode", message = "id参数有误")
    int id;
    @NotNull(message = "name不能为空")
    String name;
}

controller层

package com.example.demo0927;

import com.alibaba.fastjson.JSON;
import org.springframework.validation.BindingResult;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author liuxuewei
 */
@RestController
public class NewController {

    @RequestMapping("/t")
    public String test(@RequestBody @Valid TestRequest request, BindingResult bindingResult){

        if (bindingResult.hasErrors()) {
            List<ObjectError> allErrors = bindingResult.getAllErrors();
            List<String> errMessages = allErrors.stream().map(r -> r.getDefaultMessage()).collect(Collectors.toList());
            return errMessages.toString();
        }
        return JSON.toJSONString(request);
    }

}