Struts2框架之的类型转换

来源：不详责任编辑：admin 发表时间:2013-07-01 19:57　点击:次

下面通过一个简单的例子来描述Struts2的类型转换.
准备如下:

1.在web项目中引入Struts2框架:将相应的Jar包(commons-logging-1.0.4.jar,freemarker-2.3.8.jar,ognl-2.6.11.jar,struts2-core-2.0.11.1.jar,xwork-2.0.4.jar其它的项目中用不上,所以不需要加入)拷贝到项目的WEB-INF/lib/目录中,然后在web.xml进行如下配置:

<?xml version="1.0" encoding="UTF-8"?> 
<web-app 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"> 
<welcome-file-list> 
<welcome-file>index.jsp</welcome-file> 
</welcome-file-list> 

//增加如下过滤器 
<filter> 
<filter-name>struts</filter-name> 
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class> 
</filter> 
<filter-mapping> 
<filter-name>struts</filter-name> 
<url-pattern>/*</url-pattern> 
</filter-mapping> 

</web-app>

2.为了支持国际化所以建立:struts.properties文件和reg_zh_CN.properties文件,其内容分别如下:

//struts.properties 
//资源文件reg_zh_CN.properties的前半部份根据下面的"reg"来命名 
struts.custom.i18n.resources=reg 
//reg_zh_CN.properties 
userName=user info:

3.建立User资源类

//类User.java 

package cn.edu.hld; 

public class User 
{ 
private String userName ; 
private String userPass ; 
public String getUserName() 
{ 
return userName; 
} 
public void setUserName(String userName) 
{ 
this.userName = userName; 
} 
public String getUserPass() 
{ 
return userPass; 
} 
public void setUserPass(String userPass) 
{ 
this.userPass = userPass; 
} 

}

4.建立实现逻辑控制类

//Action控制类:OgnlTypeConvert.java 
package cn.edu.hld; 

import com.opensymphony.xwork2.ActionSupport; 

public class OgnlTypeConvert extends ActionSupport 
{ 
private User user ; 

public User getUser() 
{ 
return user; 
} 

public void setUser(User user) 
{ 
this.user = user; 
} 
public String execute() 
{ 
if(this.getUser().getUserName().equals("thtwin") && 
this.getUser().getUserPass().equals("thtwinj2ee") ) 
{ 
return SUCCESS ; 
} 
else 
{ 
return ERROR ; 
} 
} 
}

5.实现类型转换的核心类

//类型转换核心类 

package cn.edu.hld; 

import java.util.Map; 

import ognl.DefaultTypeConverter; 

public class TypeConversion extends DefaultTypeConverter 
{ 

@Override 
public Object convertValue(Map context, Object values, Class toClass) 
{ 

if(toClass == User.class) 
{ 
String strUser[] = (String[])values ; 
String userInfo[] = strUser[0].split(",") ; 
User user = new User() ; 
user.setUserName(userInfo[0]) ; 
user.setUserPass(userInfo[1]) ; 
return user ; 
} 
else if(toClass == String.class) 
{ 
String userInfo = "" ; 
User user = (User)values ; 
userInfo += "用户名为:" + user.getUserName() ; 
userInfo += "输入的密码为:" + user.getUserPass() ; 
return userInfo ; 
} 
else 
{ 
return "类型转换失败!" ; 
} 

} 

}

6.建立OgnlTypeConvert-conversion.properties(前面与Action类名一样,后面是死的都一样)文件并且与OgnlTypeConvert.class放在一起,通知系统怎么进行类型转换,其内容如下:

//说明Action中user这个属性通过cn.edu.hld.TypeConversion这个类来实现类型转换 
user=cn.edu.hld.TypeConversion

7.建立相应的index.jsp文件其内容如下:

<%@page contentType="text/html;charset=gb2312"%> 
<%@taglib uri="/struts-tags" prefix="s" %> 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
<head> 
<title>测试Struts2的类型转换</title> 
</head> 

<body> 
<form action="reg.action" method="post"> 
<s:text name="userName"></s:text> 
<input type="text" name="user"/> 
<br/> 
<input type="submit" value="Submit"/> 
</form> 
</b