Struts2 入门

Struts2 入门
很久没有看Java相关的东西了，这几天才发现Struts2 已经发布了，以前就听说Struts2就是以前的Webwork2，只是作了少许的改动而已，我以前也没看过Webwork，所以赶紧下来试了一把。
Struts2的地址：http://struts.apache.org/2.x
在Eclipse中新建了一个Tomcat工程（如果用WTP插件的话Dynamic Web工程）struts2Test，以下是添加了Library后的工程截图。
Struts2支持spring，tiles等很多技术，如果要使用，则相应的插件struts2-***-plugin.jar应该包含在classpath中，为了简单我使用struts2-all.jar。实际上用tiles的时候发现有些问题，可能是版本匹配不对，后来我采用了sitemesh来代替tiles，用sitemesh似乎比tiles更简单。
首先，应该设置好web.xml,要使用Struts2＋sitemesh，需依次设置3个filter，最后一个listener是spring的。为了使用struts2和sitemesh的标签，我把标签文件单独拷了出来。

< web-app  id ="Struts2"  version ="2.4"  xmlns ="http://java.sun.com/xml/ns/j2ee"  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"  xsi:schemaLocation ="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" >

     < display-name > Struts2

     < filter >
         < filter-name > Struts2-cleanup
         < filter-class > org.apache.struts2.dispatcher.ActionContextCleanUp
    

     < filter-mapping >
           < filter-name > Struts2-cleanup
           < url-pattern > /*
       

     < filter >
            < filter-name > sitemesh
         < filter-class > com.opensymphony.module.sitemesh.filter.PageFilter
    

     < filter-mapping >
           < filter-name > sitemesh
           < url-pattern > /*
       

     < filter >
         < filter-name > struts2
         < filter-class > org.apache.struts2.dispatcher.FilterDispatcher
    

     < filter-mapping >
         < filter-name > struts2
         < url-pattern > /*
    

     < listener >
         < listener-class > org.springframework.web.context.ContextLoaderListener
    


     < welcome-file-list >
         < welcome-file > index.html
    

    

     < taglib >
         < taglib-uri > /sitemesh-page
         < taglib-location > /WEB-INF/sitemesh-page.tld
    

     < taglib >
         < taglib-uri > /sitemesh-decorator
         < taglib-location > /WEB-INF/sitemesh-decorator.tld
    

     < taglib >
         < taglib-uri > /struts-tags
         < taglib-location > /WEB-INF/struts-tags.tld
    



要使用spring来为Struts2提供IOC，需要在源码包中的struts.properties设置objectFactory属性。
struts.action.extension  =  do
struts.custom.i18n.resources  =  globalMessages
struts.objectFactory  =  spring
struts.objectFactory.spring.autoWire  =  type
struts.ui.theme = simple
为了使用Struts2提供的i18n功能，定义了一个全局的资源文件globalMessages.properties，其内容就不给出了，该文件也放在源码包中。另外，Struts2还缺少一个配置Action的文件strtus.xml,该文件也放在源码包中；再在WEB-INF目录下新建一个spring的配置文件applicationContext.xml和sitemesh的配置文件decorator.xml。两个文件的类容分别如下，我就不解释了：


< beans  default-autowire ="autodetect" >

     < bean  id ="dataSource"
        class ="org.springframework.jdbc.datasource.DriverManagerDataSource" >
         < property  name ="driverClassName" >
             < value > com.mysql.jdbc.Driver
        
         < property  name ="url" >
             < value > jdbc:mysql://localhost:3306/forum
        
         < property  name ="username" >
             < value > test
        
         < property  name ="password" >
             < null  />
        
    


     < bean  id ="sessionFactory"
        class ="org.springframework.orm.hibernate3.LocalSessionFactoryBean" >
         < property  name ="dataSource" >
             < ref  local ="dataSource"   />
        
         < property  name ="mappingResources" >
             < list >
                 < value > cn/tju/lzy/forum/model/User.hbm.xml
                 < value > cn/tju/lzy/forum/model/Article.hbm.xml
                 < value > cn/tju/lzy/forum/model/Board.hbm.xml
            
        
         < property  name ="hibernateProperties" >
             < props >
                 < prop  key ="hibernate.dialect" >
                    org.hibernate.dialect.MySQLDialect
                
                 < prop  key ="hibernate.show_sql" > true
                 < prop  key ="hibernate.cache.provider_class" >
                    net.sf.ehcache.hibernate.SingletonEhCacheProvider
                
            
        
    

     < bean  id ="transactionManager"
        class ="org.springframework.orm.hibernate3.HibernateTransactionManager" >
         < property  name ="sessionFactory" >
             < ref  local ="sessionFactory"   />
        
    

     < bean  id ="userDAO"
        class ="cn.tju.lzy.forum.dao.hibernate.UserDAOHibernate" >
         < property  name ="sessionFactory" >
             < ref  local ="sessionFactory"   />
        
    



     < bean  id ="boardDAO"
        class ="cn.tju.lzy.forum.dao.hibernate.BoardDAOHibernate" >
         < property  name ="sessionFactory" >
             < ref  local ="sessionFactory"   />
        
    

     < bean  id ="articleDAO"
        class ="cn.tju.lzy.forum.dao.hibernate.ArticleDAOHibernate" >
         < property  name ="sessionFactory" >
             < ref  local ="sessionFactory"   />
        
    

     < bean  id ="loginAction"  singleton ="true"
        class ="cn.tju.lzy.forum.action.LoginAction" >
         < property  name ="userDAO" >
             < ref  local ="userDAO"   />
        
    

     < bean  id ="registAction"  singleton ="true"
        class ="cn.tju.lzy.forum.action.RegistAction" >
         < property  name ="userDAO" >
             < ref  local ="userDAO"   />
        
    



< decorators  defaultdir ="/decorators" >
     < excludes >
         < pattern > /decorators/main.jsp
    
     < decorator  name ="main"  page ="main.jsp" >
         < pattern > *
    

新建一个struts2的Action，完成regist功能，通常Action都继承自ActionSupport类。
package  cn.tju.lzy.forum.action;
import  cn.tju.lzy.forum.dao.UserDAO;
import  cn.tju.lzy.forum.model.User;
import  com.opensymphony.xwork2.ActionSupport;
public   class  RegistAction  extends  ActionSupport {
/**
*
*/
private   static   final   long  serialVersionUID  =   1L ;
private  String name  =   null ;
private  String password  =   null ;
private  String password2  =   null ;
private  String email  =   null ;
private  UserDAO userDAO  =   null ;
@Override
public  String execute()  throws  Exception {
//  TODO Auto-generated method stub
System.out.println( " execute() calling in LoginAction. " );
if  (userDAO.isUserExist(getName())) {
addActionError(getText( " user.name.exist " ));
return  INPUT;
}  else  {
User user  =   new  User();
user.setName(name);
user.setPwd(password);
user.setEmail(email);
userDAO.saveUser(user);
return  SUCCESS;
}
}
@Override
public   void  validate() {
if  (getName()  ==   null   ||  getName().length()  <   1 ) {
addFieldError( " name " ,getText( " user.name.empty " ));
}
if  (getPassword()  ==   null   ||  getPassword().length()  <   1 ) {
addFieldError( " password " ,getText( " user.password.empty " ));
}
if  (getPassword2()  ==   null   ||  getPassword2().length()  <   1 ) {
addFieldError( " password2 " ,getText( " user.password2.empty " ));
}
if  (getPassword()  !=   null &&! getPassword().equals(getPassword2())) {
addFieldError( " password2 " ,getText( " user.password.password2.unequal " ));
}
}
public  UserDAO getUserDAO() {
return  userDAO;
}
public   void  setUserDAO(UserDAO userDAO) {
this .userDAO  =  userDAO;
}
public  String getEmail() {
return  email;
}
public   void  setEmail(String email) {
this .email  =  email;
}
public  String getName() {
return  name;
}
public   void  setName(String name) {
this .name  =  name;
}
public  String getPassword() {
return  password;
}
public   void  setPassword(String password) {
this .password  =  password;
}
public  String getPassword2() {
return  password2;
}
public   void  setPassword2(String password2) {
this .password2  =  password2;
}
}
当然还要一些页面文件，以regist.jsp为例：
<%@ page contentType = " text/html; charset=UTF-8 " %>
<%@ taglib uri = " /sitemesh-decorator "  prefix = " decorator " %>
<%@ taglib uri = " /struts-tags "  prefix = " s " %>

< html >
< head >
< title > regist

< body >

< center >
< div  style ="color:red"  align ="left" >< s:actionerror  />
< s:form  method ="POST"  action ="regist" >
     < table  border ="0"  width ="600" >
         < thead  bgcolor ="#CCCCCC" >
             < font  size ="5" >   < b >   < s:text  name ="user.regist.form"   />    
        

         < tr >
             < td  height ="40"  width ="100"  align ="right"   >< s:text
                 name ="user.name"   />
             < td >< s:textfield  name ="name"  size ="20"   />
             < td  height ="40"  align ="left"  valign ="center"
                style ="color:red;font-size:18" >< s:fielderror >
                 < s:param > name
            
        
         < tr >
             < td  height ="40"  width ="100"  align ="right" >< s:text  name ="user.password"   />
             < td >< s:password  name ="password"  size ="20"   />
             < td  height ="40"  align ="left"  valign ="center"
                style ="color:red;font-size:18" >< s:fielderror >
                 < s:param > password
            
        
         < tr >
             < td  height ="40"  width ="100"  align ="right" >< s:text  name ="user.password2"   />
             < td >< s:password  name ="password2"  size ="20"   />
             < td  height ="40"  align ="left"  valign ="center"
                style ="color:red;font-size:18" >< s:fielderror >
                 < s:param > password2
            
        
         < tr >
             < td  height ="40"  width ="100"  align ="right" >< s:text  name ="user.email"   />
             < td >< s:textfield  name ="email"  size ="30"   />
             < td  height ="40"  align ="left"  valign ="center"
                style ="color:red;font-size:18" >< s:fielderror >
                 < s:param > email
            
        

         < tr >
             < td  height ="40"  width ="100"  align ="right" >
             < td >< s:submit  value ="%{getText(‘button.submit‘)}"   />   < s:reset
                 value ="%{getText(‘button.reset‘)}"   />   < s:submit
                 value ="%{getText(‘button.cancel‘)}"  action ="welcome" >
             < td  height ="40"  align ="right" >
        
    






最后，来看一下struts.xml
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd" >
< struts >
< package  name ="cn.tju.lzy.forum.action"  namespace ="/"
extends ="struts-default" >
< action  name ="welcome" >
< result > /pages/index.jsp

< action  name ="*_input" >
< result > /pages/{1}.jsp

< action  name ="regist"
class ="cn.tju.lzy.forum.action.RegistAction" >
< result  name ="input" > /pages/regist.jsp
< result  name ="success"  type ="redirect-action" > login

< action  name ="login"
class ="cn.tju.lzy.forum.action.LoginAction" >
< result  name ="input" > /pages/login.jsp
< result  name ="success"  type ="redirect-action" > welcome
< result  name ="cancel"  type ="redirect-action" > welcome



实际上将原来的ActionForm和Action合并了，这也许也是Struts2带来的最大变化吧，这样肯定比以前的编写两个类简单了。