后台开发需要对对象的传进来的参数进行校验，有专门的校验工具，validation bean 是基于JSR-303标准开发出来的，使用注解方式实现，及其方便，但是这只是一个接口，没有具体实现.Hibernate Validator是一个hibernate独立的包，可以直接引用，他实现了validation bean同时有做了扩展，比较强大。

要使用在pom.xml里添加依赖

<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>

对要验证的类添加的注解

一个用于VO继承的父对象，实现了一个Validate方法，可以抛出自定义异常，然后把违背约束的属性给输出出来

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.groups.Default;


public class BaseVO implements Serializable, Cloneable {
    private static final long serialVersionUID = -3282093394377931421L;
    //得到一个验证器实例
    private static Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
    //验证方法,抛出自定义异常
    public void validate() throws XXXException{
    //用Map保存错误
	Map<String, StringBuffer> errorMap = null;
    //把对象放到验证器的验证方法中，用Set存储违背约束的对象
	Set<ConstraintViolation<BaseVO>> set = validator.validate(this, Default.class);
    //当有违背约束的对象时
	if (set != null && set.size() > 0) {
        //初始化map
	    errorMap = new HashMap<String, StringBuffer>();
        //保存错误属性
	    String property = null;
	    for (ConstraintViolation<BaseVO> cv : set) {
		// 这里循环获取错误信息，可以自定义格式
		property = cv.getPropertyPath().toString();
		if (errorMap.get(property) != null) {
		    errorMap.get(property).append("," + cv.getMessage());
		} else {
		    StringBuffer sb = new StringBuffer();
		    sb.append(cv.getMessage());
		    errorMap.put(property, sb);
		}
	    }

	    if (errorMap != null) {
		StringBuffer sb = new StringBuffer();
		for (Map.Entry<String, StringBuffer> m : errorMap.entrySet()) {
		    sb.append(m.getValue().toString()).append("\r\n");
		}
        //输出
        throw new XXXException(sb.toString());
	    }

	}

    }

}

或者参照这个博客可以将其封装成工具类

package com.alibaba.banff.web.util;
 
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
 
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.groups.Default;
 
/**
 * 校验工具类
 * 
 * @author lizhilong
 */
public class ValidationUtils {
 
    private static Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
 
    public static <T> ValidationResult validateEntity(T obj) {
        ValidationResult result = new ValidationResult();
        Set<ConstraintViolation<T>> set = validator.validate(obj, Default.class);
        // if( CollectionUtils.isNotEmpty(set) ){
        if (set != null && set.size() != 0) {
            result.setHasErrors(true);
            Map<String, String> errorMsg = new HashMap<String, String>();
            for (ConstraintViolation<T> cv : set) {
                errorMsg.put(cv.getPropertyPath().toString(), cv.getMessage());
            }
            result.setErrorMsg(errorMsg);
        }
        return result;
    }
 
    public static <T> ValidationResult validateProperty(T obj, String propertyName) {
        ValidationResult result = new ValidationResult();
        Set<ConstraintViolation<T>> set = validator.validateProperty(obj, propertyName, Default.class);
        if (set != null && set.size() != 0) {
            result.setHasErrors(true);
            Map<String, String> errorMsg = new HashMap<String, String>();
            for (ConstraintViolation<T> cv : set) {
                errorMsg.put(propertyName, cv.getMessage());
            }
            result.setErrorMsg(errorMsg);
        }
        return result;
    }
}

 校验工具类返回的数据ValidationResult（省略getset）：

package com.aliyun.prophet.facade.partner.flaw;
 
import java.util.Map;
 
/**
 * 校验结果
 * 
 * @author lizhilong
 */
public class ValidationResult {
 
    // 校验结果是否有错
    private boolean             hasErrors;
 
    // 校验错误信息
    private Map<String, String> errorMsg;
}