一、獲取值棧的對象，調用值棧的set方法
1、代碼
ValuesStackAction1.java
package work.zhangdoudou.Action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.ValueStack;
public class ValuesStackAction1 extends ActionSupport{
@Override
public String execute() throws Exception {
//第一種方式使用值棧對象里面的set方法
//1取值棧對象
ActionContext context=ActionContext.getContext();
ValueStack stack=context.getValueStack();
stack.set("username", "doudou");
return SUCCESS;
}
}
struts.xml
<?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>
<constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="true" />
<package name="default" namespace="/" extends="struts-default">
<action name="userAction1" class="work.zhangdoudou.Action.ValuesStackAction1" method="execute">
<result name="success">/ValuesStack.jsp</result>
</action>
</package>
</struts>
ValuesStack.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'ValuesStackAction.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<s:debug></s:debug>
</body>
</html>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>struts2_ognl</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.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>
2、運行結果
image.png
- 有一個java.util.HashMap 這個是我們放的值
- root其實是list集合在list中放了一個map
二、獲取值棧對象，調用值棧的push方法
1、代碼
ValuesStackAction1.java
package work.zhangdoudou.Action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.ValueStack;
public class ValuesStackAction1 extends ActionSupport{
@Override
public String execute() throws Exception {
//第一種方式使用值棧對象里面的set方法
//1取值棧對象
ActionContext context=ActionContext.getContext();
ValueStack stack=context.getValueStack();
//2set方法
stack.set("username", "doudou");
//3調用push方法 最后放的為棧頂元素
stack.push("lisi");
return SUCCESS;
}
}
2、執行效果
image.png
- 它把push的元素當做字符串放進值棧
三、在action定義變量，生成get方法（常用）
1、代碼
ValuesStackAction2.java
package work.zhangdoudou.Action;
import com.opensymphony.xwork2.ActionSupport;
public class ValuesStackAction2 extends ActionSupport{
//1定義
private String name;
//2生成個get方法
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String execute() throws Exception {
//在執行的方法里向變量設置值
name="wangwu";
return SUCCESS;
}
}
struts.xml
<action name="userAction2" class="work.zhangdoudou.Action.ValuesStackAction2" method="execute">
<result name="success">/ValuesStack.jsp</result>
</action>
2、運行結果
image.png
- 這樣做不用重新分配空間，可以減少空間的langfeo
