Spring 校验（validator，JSR-303）简单实现

利用Spring MVC 与 hibernate的JSR-303规范结合实现后台校验（简单案例）：

• 什么是JSR-303规范
• 与Spring MVC结合
• 实体类添加验证注解
• *控制器验证注解添加

什么是JSR-303规范

JSR 303是Java EE 6中的一项子规范，叫做Bean Validation，官方参考实现是hibernate Validator，此实现与Hibernate ORM没有任何关系。JSR 303用于对Java Bean中的字段的值进行验证。

与Spring MVC结合

Spring-mvc.xml配置：

    <!--JSR-303-->     <mvc:annotation-driven validator="validator"/>      <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">         <property name="providerClass" value="org.hibernate.validator.HibernateValidator"/>         <property name="validationMessageSource" ref="messageSource"/>     </bean>     <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">         <property name="basename" value="validatemessage"/>         <property name="useCodeAsDefaultMessage" value="false"/>         <property name="defaultEncoding" value="UTF-8"/>         <property name="cacheSeconds" value="60"/>     </bean>     <bean  id="webBindingInitializer" class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">         <property name="conversionService">             <bean class="org.springframework.format.support.FormattingConversionServiceFactoryBean"></bean>         </property>         <property name="validator" ref="validator"/>     </bean>

实体类添加验证注解

这里贴出部分代码，知道如何加注解即可：

 import com.lemontree.common.utils.AjaxResult; import com.lemontree.common.utils.StringUtil; import com.lemontree.common.utils.email.EmailUtils; import org.hibernate.validator.constraints.NotEmpty;  import java.util.Date;  public class User {     /**      * This field was generated by MyBatis Generator.      * This field corresponds to the database column user.id      *      * @mbg.generated Thu Mar 16 13:27:38 CST 2017      */     private Integer id;      /**      * This field was generated by MyBatis Generator.      * This field corresponds to the database column user.user_name      *      * @mbg.generated Thu Mar 16 13:27:38 CST 2017      */     @NotEmpty(message = "用户名不能为空")     private String userName;      /**      * This field was generated by MyBatis Generator.      * This field corresponds to the database column user.password      *      * @mbg.generated Thu Mar 16 13:27:38 CST 2017      */     @NotEmpty(message = "密码不能为空")     private String password;     } 

控制器验证注解添加

将@Validated 注解跟在实体类前面，BindingResult紧跟其后：

    @RequestMapping(value = "/login.htm", method = RequestMethod.POST)     public @ResponseBody AjaxResult login(@Validated User user, BindingResult bindingResult,                                           HttpServletRequest request, HttpServletResponse response) {         if (bindingResult.hasErrors()){             List<FieldError> errorses = bindingResult.getFieldErrors();             if (CollectionUtils.isNotEmpty(errorses)){                 errorses.forEach(item->{                     System.out.println(item.getDefaultMessage());                 });             }         }       }