Struts2数据转换实例之数组转换

MVC的设计模式，存在从用户WEB页面输入和实际JavaBean属性之间的自动类型转换问题

功能需求：页面上输入“用户名，密码”，将前半部分自动映射到User类的username属性中，将后半部分自动映射到User类的password属性中

User.java




package HelloWorld;






public class User ...{


private String username;


private String password;


private String[] books;




public String[] getBooks() ...{


return books;


}




public void setBooks(String[] books) ...{


this.books = books;


}




public String getUsername() ...{


return username;


}




public void setUsername(String username) ...{


this.username = username;


}




public String getPassword() ...{


return password;


}




public void setPassword(String password) ...{


this.password = password;


}


}



LoginAction.java




package HelloWorld;




import com.opensymphony.xwork2.Action;


import com.opensymphony.xwork2.ActionContext;






public class LoginAction implements Action...{








private String tip;




private User user;






public User getUser() ...{


return user;


}






public void setUser(User user) ...{


this.user = user;


}






public String execute() throws Exception...{




if(this.getUser().getUsername().equals("admin")&&this.getUser().getPassword().equals("1234"))...{


ActionContext.getContext().getSession().put("user", this.getUser().getUsername());


BookService bs=new BookService();


this.getUser().setBooks(bs.getBooks());


this.setTip("welcome welcome");


return SUCCESS;




}else...{


return ERROR;


}


}






public String getTip() ...{


return tip;


}




public void setTip(String tip) ...{


this.tip = tip;


}









}





LoginAction的类型转换器，实现从String到User的双向转换




package HelloWorld;




import java.util.Map;




import ognl.DefaultTypeConverter;






public class UserConverter extends DefaultTypeConverter ...{









public Object convertValue(Map context, Object value, Class toType)




...{


if (toType == User.class )




...{


String[] params = (String[])value;


User user = new User();


String[] userValues = params[0].split(",");


user.setUsername(userValues[0]);


user.setPassword(userValues[1]);


return user;




}


else if (toType == String.class )




...{


User user = (User) value;


return "<" + user.getUsername() + "," + user.getPassword() + ">";


}


return null ;


}


}








转换器配置文件（命名规则为ActionName-convrsion.proipertoes,如果是全局的，命名为xwork.conversion.properties）,局部配置文件放在和Action同一个目录下，如果是全局的配置文件，则放到WEB-INF/classes下

user=HelloWorld.UserConverter （Action中的user对象使用UserConverter转换器）



web.xml

<?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">
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>



struts.xml(WEB-INF/classes下)

<?xml version="1.0" encoding="GBK" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
<package name="struts" extends="struts-default">
<action name="Login" class="HelloWorld.LoginAction">
<result name="input">/helloworld/index.jsp</result>
<result name="success">/helloworld/welcome.jsp</result>

<result name="error">/helloworld/error.jsp</result>
</action>
</package>
</struts>



struts.properties (WEB-INF/classes下)

struts.custom.i18n.resources=messageResource



messageResource.properties

pass.required = /u5BC6/u7801/u5FC5/u987B/u8F93/u5165
password = /u7528/u6237/u5BC6/u7801
user.required = /u7528/u6237/u540D/u5FC5/u987B/u8F93/u5165
username = /u7528/u6237/u59D3/u540D