bean validation跟springmvc里不进行验证，BindingResult的errors一直是0

照着官方文档和一大堆教程的配置，但是就是不进行验证，BindingResult的errors一直是0, hibernate-validator-5.1.3.Final.jar 和 validation-api-1.1.0.Final.jar 都导了，也没报错，就是明明我提交的是空信息但是errors一直是0。

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"

         version="3.1">

    <servlet>

        <servlet-name>spring</servlet-name>

        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <load-on-startup>1</load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>spring</servlet-name>

        <url-pattern>/</url-pattern>

    </servlet-mapping>



    <filter>

        <filter-name>characterEncodingFilter</filter-name>

        <filter-class>

            org.springframework.web.filter.CharacterEncodingFilter

        </filter-class>

        <init-param>

            <param-name>encoding</param-name>

            <param-value>UTF-8</param-value>

        </init-param>

    </filter>

    <filter-mapping>

        <filter-name>characterEncodingFilter</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

</web-app>

spring-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:p="http://www.springframework.org/schema/p"

       xmlns:context="http://www.springframework.org/schema/context"

       xmlns:mvc="http://www.springframework.org/schema/mvc"

       xsi:schemaLocation="http://www.springframework.org/schema/beans

        http://www.springframework.org/schema/beans/spring-beans.xsd

        http://www.springframework.org/schema/context

        http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:component-scan base-package="com.yg.controller"/>

    <mvc:annotation-driven/>



    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="prefix" value="/"/>

        <property name="suffix" value=".jsp"/>

    </bean>





</beans>

User实体类

package com.yg.entity;



import org.hibernate.validator.constraints.NotBlank;

import org.hibernate.validator.constraints.NotEmpty;



import javax.validation.constraints.NotNull;

import javax.validation.constraints.Null;

import javax.validation.constraints.Size;



/**

 * Created by 光 on 2015/3/3.

 */

public class User {

    @NotEmpty(message = "不能为空")

    private String userName;

    @Size(min = 5,max = 12,message = "密码长度为5-12位")

    private String password;

    private String nickName;





    public User() {

    }



    public User(String userName, String password, String nickName) {

        this.userName = userName;

        this.password = password;

        this.nickName = nickName;

    }

    

    public String getUserName() {

        return userName;

    }

    

    public String getPassword() {

        return password;

    }

    

    public String getNickName() {

        return nickName;

    }



    public void setUserName(String userName) {

        this.userName = userName;

    }



    public void setPassword(String password) {

        this.password = password;

    }



    public void setNickName(String nickName) {

        this.nickName = nickName;

    }

}

UserController类

package com.yg.controller;



import com.yg.entity.User;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.validation.BindingResult;

import org.springframework.validation.Errors;

import org.springframework.validation.annotation.Validated;

import org.springframework.web.bind.annotation.ModelAttribute;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;



import javax.validation.*;

import java.util.ArrayList;

import java.util.List;

import java.util.Set;



/**

 * Created by 光 on 2015/3/3.

 */

@Controller

@RequestMapping("/user")

public class UserController {

    private List<User> userList = new ArrayList<User>();



    public UserController() {

        userList.add(new User("luffy","123","路飞"));

        userList.add(new User("nami","123","娜美"));

        userList.add(new User("zero","123","索隆"));

        userList.add(new User("sanji","123","香吉士"));

    }



    @RequestMapping("/users")

    public String list(Model model){

        model.addAttribute("users", userList);

        return "/user/list";

    }



    @RequestMapping(value = "/add",method = RequestMethod.GET)

    public String add(Model model){

        model.addAttribute(new User());

        return "/user/add";

    }



    @RequestMapping(value = "/add",method = RequestMethod.POST)

    public String add(@Validated User user,BindingResult br){

        System.out.println(br.getAllErrors().size());

        if(br.hasErrors()){

            System.out.println("进入");

            return "/user/add";

        }

        userList.add(user);

        return "redirect:/user/users";

    }

}

添加信息的add.jsp

<%--

  Created by IntelliJ IDEA.

  User: 光

  Date: 2015/3/4

  Time: 10:20

  To change this template use File | Settings | File Templates.

--%>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%@taglib prefix="sf" uri="http://www.springframework.org/tags/form" %>

<html>

<head>

    <title>添加用户</title>

</head>

<body>



<sf:form method="post" modelAttribute="user">

    <sf:input path="userName" /><sf:errors path="userName"/> <br/>

    <sf:password path="password"/><br/>

    <sf:input path="nickName"/><br/>

    <input type="submit" value="提交">

</sf:form>





</body>

</html>

我整了一天了，也没报错，就是不进行验证，对比了N个教程和官方文档都一样，但是别人的验证，我的没验证，实在没法了，求教啊