上篇讲到数据绑定的数据转化，接下来我们开一下数据校验，这边主要讲一下JSR-303整合到SpringMVC中。

pom.xml

 <properties>
        <hibernate-validator.version>5.2.4.Final</hibernate-validator.version>
        <validation-api.version>1.1.0.Final</validation-api.version>
    </properties>
<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>${validation-api.version}</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>${hibernate-validator.version}</version>
</dependency>

dispatcher-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 校验器注入到处理器适配器中 -->
    <mvc:annotation-driven validator="validator"/>
    <context:component-scan base-package="validator"/>

    <!-- 国际化的消息资源文件（本系统中主要用于显示/错误消息定制） -->
    <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basenames">
            <list>
                <!-- 在web环境中一定要定位到classpath 否则默认到当前web应用下找  -->
                <value>classpath:messages</value>
            </list>
        </property>
        <property name="useCodeAsDefaultMessage" value="false"/>
        <property name="defaultEncoding" value="UTF-8"/>
        <property name="cacheSeconds" value="60"/>
    </bean>

    <!-- 以下 validator  ConversionService 在使用 mvc:annotation-driven 会自动注册-->
    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
        <!-- hibernate校验器-->
        <property name="providerClass" value="org.hibernate.validator.HibernateValidator"/>
        <!-- 如果不加默认到 使用classpath下的 ValidationMessages.properties -->
        <property name="validationMessageSource" ref="messageSource"/>
    </bean>

    <!-- ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

messages.properties

user.id.null=用户编号不能为空
user.name.null=用户名不能为空
user.name.length.illegal=用户名长度必须在5到20之间
user.name.illegal=用户名必须是字母
user.password.null=密码不能为空

核心类

@Data
public class User implements Serializable {
    //使用自定义错误信息
    @NotNull(message = "{user.id.null}")
    private Long id;
    @NotEmpty(message = "{user.name.null}")
    @Length(min = 5, max = 20, message = "{user.name.length.illegal}")
    @Pattern(regexp = "[a-zA-Z]{5,20}", message = "{user.name.illegal}")
    private String name;
    @NotNull(message = "{user.password.null}")
    private String password;
}
@Controller
public class UserController {
    @RequestMapping("/save")
    //BindingResult讲保存错误信息，到时候自己根据业务处理
    public String save(@Valid User user, BindingResult result) {
        if (result.hasErrors()) {
            return "error";
        }
        return "success";
    }
}