Java Struts2转换器

Struts2提供了强有力的表现层类型转换机制，能自动处理类型转换过程中出现的未知异常。

eg：登录提交

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML>
<html>
  <head> 
    <title>test</title>
    <meta charset="utf-8">
  </head>
  
  <body>
    <form action="login" methor="post">
    	<p>用户：<input type="text" name="user"/></p>
    	<p><input type="submit" value="submit"/></p>
    </form>
  </body>
</html>

result.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'result.jsp' starting page</title>
  </head>
  <body>
    <p>用户姓名：<s:property value="user.name"/></p>
    <p>用户密码：<s:property value="user.pass"/></p>
  </body>
</html>

struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>  
	<package name="default" extends="struts-default">
		<action name="login" class="top.k10000.UserAction">
			<result name="success">/result.jsp</result>
		</action>
	</package>  
</struts>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 
	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_3_0.xsd">
  <display-name></display-name>	
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
  <filter>
  	<filter-name>struts2</filter-name>
  	<filter-class>
  		org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
  	</filter-class>
  </filter>
  <filter-mapping>
  	<filter-name>struts2</filter-name>
  	<url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>

User.java

package top.k10000;

public class User {
    private String name;
    private String pass;
    public void setName(String str_name){
		this.name = str_name;
	}
	public String getName(){
		return name;
	}
	public void setPass(String str_pass) {
		this.pass = str_pass;
	}
	public String getPass() {
		return pass;
	}
	
}

UserAction.java

package top.k10000;
import com.opensymphony.xwork2.ActionSupport;
public class UserAction extends ActionSupport{
    private User user;

    public User getUser() {
        
        return user;
    }
    public void setUser(User user) {
        
        this.user = user;
    }
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        
        return SUCCESS;
    }
    
}

UserConverter.java

package top.k10000;

import java.util.Map;  

import org.apache.struts2.util.StrutsTypeConverter;  
  
import com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter;  
  
public class UserConverter extends StrutsTypeConverter{  
    @Override  
    public Object convertFromString(Map context, String[] values, Class toClass) {  
        // TODO Auto-generated method stub  
        User user=new User();  
        String[]userValue=values[0].split(",");  
        user.setName(userValue[0]);  
        user.setPass(userValue[1]);  
        return user;  
    }  
  
    @Override  
    public String convertToString(Map context, Object o) {  
        // TODO Auto-generated method stub  
        User user=(User) o;  
        return "<"+user.getName()+user.getPass()+">";  
    }  
}

在UserAction.java所在的包中配置注册转换器，创建properties文件，格式为Action类名-conversion.properties

/Struts2_zq/src/top/k10000/UserAction-conversion.properties