创建Action类
package cn.w3cschool.struts2; public class HelloWorldAction{ private String name; public String execute() throws Exception { return "success"; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
创建视图
接着创建如下index.jsp文件:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <%@ taglib prefix="s" uri="/struts-tags"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "Http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Hello World</title> </head> <body> <h1>Hello World From Struts2</h1> <form action="hello"> <label for="name">Please pick a name</label><br/> <select name="name"> <option name="Mike">Mike</option> <option name="Jason">Jason</option> <option name="Mark">Mark</option> </select> <input type="submit" value="Say Hello"/> </form> </body> </html>然后让我们用HelloWorld.jsp来演示如何使用if,else和elseif标签:
<%@ page contentType="text/html; charset=UTF-8" %> <%@ taglib prefix="s" uri="/struts-tags" %> <html> <head> <title>Example of If and Else</title> </head> <body> <b>Example of If and Else</b><br/> <s:if test="name=='Mike'"> You have selected 'Mike'. </s:if> <s:elseif test="name=='Jason'"> You have selected 'Jason' </s:elseif> <s:else> You have not selected 'Mike' or 'Jason'. </s:else> </body> </html>这里,如果在“test”属性中指定的条件返回true,if标签返回true。在我们的例子中,我们将其与“Mike”进行比较。如果名称是Mike,标签返回true,则印出字符串;否则“elseif”块被执行,如果不满足,则else块被执行。这与在Java语言中传统的if,else if和else没有区别。
配置文件
你的struts.xml文件应如下:<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE struts PUBLIC "-//Apache Software foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <constAnt name="struts.devMode" value="true" /> <package name="helloworld" extends="struts-default"> <action name="hello" class="cn.w3cschool.struts2.HelloWorldAction" method="execute"> <result name="success">/HelloWorld.jsp</result> </action> </package> </struts>你的web.xml文件应如下:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>Struts 2</display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <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>现在,右键单击项目名称,然后单击“Export”> “WAR File”以创建WAR文件。然后在Tomcat的webapps目录中部署WAR文件。最后,启动Tomcat服务器并尝试访问URL http://localhost:8080/HelloWorldStruts2/index.jsp,将显示以下界面:
现在选择“Mark”并提交页面,你会看到以下页面: