基于javax的validator实现自定义的注解进行参数校验

因为一些特性的校验规则，validator自带的注解并不能完全满足需求，当然它也提供了正则校验，但是正则校验只能是字符串类型，当我遇到需要校验byte类型的参数时，只能想到了实现自定义注解。

1.首先需要依赖包，我这里用到的是hibernate-validator包

<dependency>
	<groupId>org.hibernate.validator</groupId>
	<artifactId>hibernate-validator</artifactId>
</dependency>

2.添加自定义注解 ByteCheck 注解类

package com.bn.lbs.base.annotation;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.*;

/**
 * @author king
 */
@Documented
@Constraint(validatedBy = CheckByteValidator.class)
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
public @interface ByteCheck {

    String message() default "请传入符合要求的Byte值";

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

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

}

3.自定义枚举校验的处理类，该类必须实现ConstraintValidator接口

package com.bn.lbs.base.annotation;

import org.springframework.util.StringUtils;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.regex.Pattern;

/**
 * @author king
 */
public class CheckByteValidator implements ConstraintValidator<ByteCheck, Byte> {
    @Override
    public void initialize(ByteCheck constraintAnnotation) {
    }

    @Override
    public boolean isValid(Byte value, ConstraintValidatorContext context) {
        if(StringUtils.isEmpty(value)){
            return false;
        }
        String regex = "^[0|1]$";
        return Pattern.matches(regex, String.valueOf(value));
    }
}

4.在代码中添加相应的注解

  /**
   * 是否启用
   * 1/0 禁用/启用
   */
  @ApiModelProperty(value = "1/0 禁用/启用")
  @ByteCheck(message = "启用状态字段只能为 启用或禁用")
  private Byte isDisabled;

5.校验可以在controller中添加@validator或者@valid注解，我这里用的是自定义返回处理，所以封装了校验器工具类

package  com.bn.lbs.base.support;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import java.util.*;

/**
* 两种方法，只是返回结果形式不同而已
*/
public class ValidatorUtils {
	protected static Logger logger = LoggerFactory.getLogger("com.bn.lbs.base.support.ValidatorUtils");
	public static Map<String, String> validator(Object obj) {
		Map<String, String> errors = new HashMap<String, String>();
		 ValidatorFactory vf = Validation.buildDefaultValidatorFactory();  
	     Validator validator = vf.getValidator();  
	     Set<ConstraintViolation<Object>> validate = validator.validate(obj);
	     for (ConstraintViolation<Object> cv : validate) { 
	    	 System.err.println(cv);
	    	 String key = cv.getPropertyPath().toString();
			 String msg = cv.getMessage();
			 if (errors.containsKey(key)) {
					String last = errors.get(key);
					errors.put(key, msg + "&" + last);
				} else {
					errors.put(key, msg);
				}
	     }
	     if(errors.size()>0) {
	         logger.error("参数较验结果:{}",errors.toString());
	     }
	     return errors;
	}


	public static List<String> validatorList(Object obj) {
		List<String> errorList= new ArrayList<>();
		Map<String, String> errors = new HashMap<String, String>();
		ValidatorFactory vf = Validation.buildDefaultValidatorFactory();
		Validator validator = vf.getValidator();
		Set<ConstraintViolation<Object>> validate = validator.validate(obj);
		for (ConstraintViolation<Object> cv : validate) {
			System.err.println(cv);
			String key = cv.getPropertyPath().toString();
			String msg = cv.getMessage();
			if (errors.containsKey(key)) {
				String last = errors.get(key);
				errors.put(key, msg + "&" + last);
			} else {
				errors.put(key, msg);
			}
		}
		errors.forEach((x,y)->{errorList.add(y);});
		if(errorList.size()>0) {
			logger.error("参数较验结果:{}",errorList.toString());
		}
		return errorList;
	}
}

附：Controller中直接加上@Validated 或 @Valid方式

@RequestMapping("/test")
public ApiResp doSomething(@Validated @RequestBody TestRequest request) {
    log.info("doSomething");
    log.info(request.toString());
    return ApiResp.retOK();
}