import javax.validation.constraints.Min;

import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.NotBlank;

public class User {

    private String username;

    private String password;

    private int age;

    @NotBlank(message="用户名不能为空")

    public String getUsername() {

       return username;

    }

    public void setUsername(String username) {

       this.username = username;

    }

    @NotNull(message="密码不能为null")

    public String getPassword() {

       return password;

    }

    public void setPassword(String password) {

       this.password = password;

    }

    @Min(value=10, message="年龄的最小值为10")

    public int getAge() {

       return age;

    }

    public void setAge(int age) {

       this.age = age;

    }

}

<?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: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-3.0.xsd

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

     http://www.springframework.org/schema/context/spring-context-3.0.xsd

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

     http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <mvc:annotation-driven/>

</beans>

import javax.validation.Valid;

import org.springframework.stereotype.Controller;

import org.springframework.validation.BindingResult;

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

@Controller

public class UserController {

    @RequestMapping("login")

    public String login(@Valid User user, BindingResult result) {

       if (result.hasErrors())

           return "user/login";

       return "redirect:/";

    }

}