初学Struts2

1、新建工程，引用Struts2

项目结构如下：

2、Web配置，web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <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>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

3、Struts配置：

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
        "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
    <package name="demo.controllers" extends="struts-default">
        <action name="HelloWord" class="demo.controllers.HelloWord"> --配置Action名称
            <result>helloword.jsp</result>  --配置action 执行成功后返回的页面
            <result name="error">error.jsp</result> --配置Action执行返回error时的页面
        </action>
    </package>
</struts>

4、Controller:

package demo.controllers;

import com.opensymphony.xwork2.ActionSupport;
import java.text.DateFormat;
import java.util.Date;

/**
 * Created by Administrator on 2014/11/13.
 */
public class HelloWord extends ActionSupport{

    private String message;

    public String getMessage() {
        return message;
    }

    public String execute(){
        message="hello word now is:"+ DateFormat.getInstance().format(new Date());
        return ERROR;  --由Struts中HelloWord 中result name="error" 指定页面显示

} }

　说明：Action返回一个结果的名字字符串，如SUCCESS,ERROR；从Struts中读取映射信息。一个给定的结果字符串将返回指定的资源返回给客户端