Validator框架的使用

Validator一般用来验证前端页面传过来的数据 是否符合预期
下面是所需要的maven

    <dependency>
      <groupId>javax.validation</groupId>
      <artifactId>validation-api</artifactId>
      <version>1.1.0.Final</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-validator</artifactId>
      <version>5.4.1.Final</version>
    </dependency>

一般用在VO类中, 用法就是直接在变量上面加上注解 如下

package com.aekc.mmall.param;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.NotBlank;

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;

public class UserParam {

    private Integer id;

    @NotBlank(message = "用户名不能为空")
    @Length(min = 1, max = 20, message = "用户名长度")
    private String username;

    @NotBlank(message = "电话不可以为空")
    @Length(min = 1, max = 13, message = "电话长度需要在13个字符以内")
    private String telephone;

    @Email
    @NotBlank(message = "邮箱不能为空")
    private String mail;

    @NotNull(message = "必须指定用户状态")
    @Min(value = 0, message = "用户状态不合法")
    @Max(value = 1, message = "用户状态不合法")
    private Integer status;
}

想要使用该状态检验功能 还需引入一个类

package com.aekc.mmall.utils;

import com.aekc.mmall.exception.ParamException;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.apache.commons.collections.MapUtils;

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

public class BeanValidator {

    private static ValidatorFactory validatorFactory = Validation.buildDefaultValidatorFactory();

    public static <T> Map<String, String> validate(T t, Class... groups) {
        Validator validator = validatorFactory.getValidator();
        Set validateResult = validator.validate(t, groups);
        if(validateResult.isEmpty()) {
            return Collections.emptyMap();
        }else {
            LinkedHashMap errors = Maps.newLinkedHashMap();
            Iterator iterator = validateResult.iterator();
            while(iterator.hasNext()) {
                ConstraintViolation violation = (ConstraintViolation) iterator.next();
                errors.put(violation.getPropertyPath().toString(), violation.getMessage());
            }
            return errors;
        }
    }

    public static Map<String, String> validateList(Collection<?> collection) {
        Preconditions.checkNotNull(collection);
        Iterator iterator = collection.iterator();
        Map errors;
        do {
            if(!iterator.hasNext()) {
                return Collections.emptyMap();
            }
            Object object = iterator.next();
            errors = validate(object, new Class[0]);
        }while(errors.isEmpty());
        return errors;
    }

    public static Map<String, String> validateObject(Object first, Object... objects) {
        if(objects != null && objects.length > 0) {
            return validateList(Lists.asList(first, objects));
        }else {
            return validate(first, new Class[0]);
        }
    }

    /**
     * 把需要检测的bean引用该方法即可
     * @param param VO
     * @throws ParamException
     */
    public static void check(Object param) throws ParamException {
        Map<String, String> map = BeanValidator.validateObject(param);
        // 如果并不为空说明有错误信息
        if(MapUtils.isNotEmpty(map)) {
            // 异常处理
        }
    }
}

这是Controller

    @ResponseBody
    @RequestMapping("/test.json")
    public ResultJson test(UserParam param) {
        BeanValidator.check(param);
    }