SpringMVC与SiteMesh2.4无缝整合并借助JSR303规范实现表单验证

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">   <servlet>
		<servlet-name>user</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>user</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

	<filter>
		<filter-name>sitemesh</filter-name>
		<filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>sitemesh</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<filter>
		<filter-name>SpringCharacterEncodingFilter</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>SpringCharacterEncodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
</web-app>

<?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-3.0.xsd 					 http://www.springframework.org/schema/mvc 					 http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd 					 http://www.springframework.org/schema/context 
					 http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 	<context:component-scan base-package="com.jadyer"/>
	
	<!-- 如果ClassPath中有JSR-303的实现，例如Hibernate-Validator，则支持@Valid修饰的参数 -->
	<!-- JSR-303 support will be detected on classpath and enabled automatically -->
	<mvc:annotation-driven/>
	
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/"/>
		<property name="suffix" value=".jsp"/>
	</bean>
</beans>

<?xml version="1.0" encoding="UTF-8"?>
<decorators defaultdir="/WEB-INF/sitemesh/">
	<decorator name="main" page="basic.jsp">
		<pattern>/*</pattern>
	</decorator>
</decorators>

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="decorator" uri="http://www.opensymphony.com/sitemesh/decorator"%>
<h1>User Manager</h1>
<hr/>
<decorator:body/>

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<form:form method="POST" modelAttribute="user">
	username:<form:input path="username"/><form:errors path="username"/><br/>
	nickname:<form:input path="nickname"/><form:errors path="nickname"/><br/>
	password:<form:password path="password"/><form:errors path="password"/><br/>
	email:<form:input path="email"/><form:errors path="email"/><br/>
	<input type="submit"/>
</form:form>

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<c:forEach items="${users}" var="user">
	${user.value.username}----${user.value.nickname}----${user.value.password}----${user.value.email}
	<br/>
</c:forEach>
<a href="<%=request.getContextPath()%>/user/add">继续添加新用户</a>

package com.jadyer.model;

import javax.validation.constraints.Size;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.NotEmpty;

/**
 * User
 * @see ===================================================================================================
 * @see JSR303是JavaEE6中的一项子规范,叫做BeanValidation,它的官方参考实现是hibernate-validator
 * @see BeanValidation现在一共有两个规范:BeanValidation1.0(即JSR303)和BeanValidation1.1(即JSR349)
 * @see BeanValidation的官网是http://beanvalidation.org/
 * @see 关于JSR303的详细说明,请参考http://jcp.org/en/jsr/detail?id=303
 * @see 关于JSR349的详细说明,请参考http://jcp.org/en/jsr/detail?id=349
 * @see ===================================================================================================
 * @see JSR303规范主要用于对JavaBean中的字段的值的验证,使得验证逻辑从业务代码中脱离出来
 * @see JSR303定义了基于注解方式的JavaBean验证元数据模型和API,也可通过XML进行元数据定义,但注解会覆盖XML的定义
 * @see JSR303主要是对JavaBean进行验证,而没有指定方法级别(参数or返回值)、依赖注入等验证,因此催生了JSR349规范
 * @see JSR349规范目前处于草案状态,它主要支持依赖注入的验证和方法级别的验证(方法的参数和返回值)
 * @see Spring3.1目前已经完全支持依赖注入验证和方法级别的验证了,只不过不是原生的(JSR349规范还是草案嘛)
 * @see 关于这个的详细说明,可以参考此爷的文章http://www.iteye.com/topic/1123007
 * @see ===================================================================================================
 * @see 另外,Struts2已经可以很完美的和JSR303整合到一起了,呵呵,很是叫我欣慰啊!!!!
 * @see ===================================================================================================
 * @see 我们这里使用的是JSR303的hibernate-validator实现,它主要需要以下三个jar包
 * @see jboss-logging-3.1.0.CR2.jar
 * @see validation-api-1.0.0.GA.jar
 * @see hibernate-validator-4.3.0.Final.jar
 * @see ===================================================================================================
 * @author http://blog.csdn.net/jadyer  * @create May 12, 2012 3:00:46 AM
 */
public class User {
	@NotEmpty(message="姓名不能为空")
	private String username;
	private String nickname;
	@Size(min=3, max=10, message="密码长度必须大于3小于10")
	private String password;
	@NotEmpty(message="邮箱不能为空")
	@Email(message="邮箱格式不正确") //也可通过@Pattern(regexp="")书写正则来判断，二者都是JSR303规范中的
	private String email;
	
	public User() {}
	public User(String username, String nickname, String password, String email) {
		this.username = username;
		this.nickname = nickname;
		this.password = password;
		this.email = email;
	}
	
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getNickname() {
		return nickname;
	}
	public void setNickname(String nickname) {
		this.nickname = nickname;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
}

package com.jadyer.controller;

import java.util.HashMap;
import java.util.Map;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.jadyer.model.User;

/**
 * @see ====================================================================================
 * @see SpringMVC中借助JSR303规范进行表单验证
 * @see 第一步：在实体类中针对需要验证的属性，进行Annotation配置
 * @see 第二步：在Controller的方法参数前使用@Valid开启JSR303验证，并添加BindingResult参数
 * @see        BindingResult承载着JSR303验证时所产生的message，可据此进行判断验证结果
 * @see 第三步：判断BindingResult中是否装载了JSR303验证的message，有则转到前台页面显示出来
 * @see 第四步：前台页面中使用<form:errors path="username"/>打印JSR303的message信息
 * @see ====================================================================================
 * @see SpringMVC与sitemesh2.4无缝整合
 * @see 第一步:拷贝sitemesh-2.4.jar到工程中
 * @see 第二步:在web.xml中配置com.opensymphony.sitemesh.webapp.SiteMeshFilter
 * @see 第三步:创建并编辑sitemesh配置文件decorators.xml
 * @see 第四步:创建并编辑/WEB-INF/sitemesh/basic.jsp
 * @see ====================================================================================
 * @author http://blog.csdn.net/jadyer  * @create May 12, 2012 3:20:46 AM
 */
@Controller
@RequestMapping("/user")
public class UserController {
	private final static Map<String,User> users = new HashMap<String,User>();

	@RequestMapping(value="/add", method=RequestMethod.GET)
	public String addUser(Model model){
		model.addAttribute(new User());
		return "user/add";
	}
	@RequestMapping(value="/add", method=RequestMethod.POST)
	public String addUser(@Valid User user, BindingResult binding){
		//该方法若有其它参数，应写成这样addUser(@Valid User user, BindingResult binding, String job)
		//就是说，这里一定要把BindingResult放在待验证对象(@Valid User user)参数的后面，否则会报错
		if(binding.hasErrors()){
			return "user/add";
		}
		users.put(user.getUsername(), user);
		return "redirect:/user/list";
	}
	
	@RequestMapping("/list")
	public String list(Model model){
		model.addAttribute("users", users);
		return "user/list";
	}
}