检查详细示例（Check Detailed Example）1

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2023-12-01

创建Action类 (Create Action Class)

package cn.xnip.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 (Create Views)

让我们有index.jsp文件如下 -

<%@ 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>
      lt;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>

接下来让我们使用HelloWorld.jsp来演示if, else和elseif标签的使用 -

<%@ 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“test”属性中指定的条件返回true，则“if”标记返回true。在我们的例子中，我们将其与“迈克”进行比较。如果名称是Mike，则标记返回true并打印字符串，否则执行“elseif”块，如果不满足，则执行else块。这与Java语言中的常规if，else if和else相同没有区别。

配置文件 (Configuration Files)

你的struts.xml看起来应该像 -

<?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.xnip.struts2.HelloWorldAction" 
         method = "execute">
         <result name = "success">/HelloWorld.jsp</result>
      </action>
   </package>
</struts>

您的web.xml应该如下所示 -

<?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>

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目录中部署此WAR。最后，启动Tomcat服务器并尝试访问URL http://localhost:8080/HelloWorldStruts2/index.jsp 。这将产生以下屏幕 -

现在选择“标记”并提交页面。你应该看到下一页。