一、源码：
struts.xml文件：
<?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.action.extension" value="action,do," /> <constant name="struts.devMode" value="true" /> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <package name="default" namespace="/" extends="struts-default"> <default-action-ref name="default" /> <action name="test1" class="org.Test.action.TestAction1" method="test"> <result>/success.jsp</result> </action> <action name="test2" class="org.Test.action.TestAction2" method="test"> <result>/success.jsp</result> </action> <action name="test3" class="org.Test.action.TestAction3" method="test"> <result>/success.jsp</result> </action> <action name="test4" class="org.Test.action.TestAction4" method="test"> <result>/success.jsp</result> </action> <action name="default"> <result>/index.jsp</result> </action> </package> </struts>
success.jsp页面：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>成功</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">
</head>
<body>
${requestScope.name}
${sessionScope.name}
${applicationScope.name}
<br>
</body>
</html>方法一：通过ServletActionContext来訪问
TestAction3.java文件：
package org.Test.action;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;
import com.opensymphony.xwork2.ActionSupport;
public class TestAction3 extends ActionSupport {
private HttpServletRequest request;
private HttpServletResponse response;
private HttpSession session;
private ServletContext application;
public TestAction3(){ //构造函数内获取四个对象
this.request = ServletActionContext.getRequest();
this.response = ServletActionContext.getResponse();
this.session = this.request.getSession();
this.application = ServletActionContext.getServletContext();
}
public String test() throws IOException {
System.out.println("TestAction3:test");
this.request.setAttribute("name", "Jack");
this.session.setAttribute("name", "Rose");
this.application.setAttribute("name", "Dean");
return SUCCESS;
}
}执行结果：
说明：
1.TestAction3的
类中：定义真实类型的request,response,session,application对象
构造方法中：通过ServletActionContext获取request,response和application。session可由request.getSession();得到
test()方法中：用setAttribute方法设置属性
2.success.jsp：通过EL语言查看request,session,application对象的name属性的值
方法二：IOC(控制反转)，通过实现接口ServletRequestAware,ServletResponseAware, ServletContextAware来訪问
TestAction4.java文件：
package org.Test.action;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.interceptor.SessionAware;
import org.apache.struts2.util.ServletContextAware;
import com.opensymphony.xwork2.ActionSupport;
public class TestAction4 extends ActionSupport implements ServletRequestAware,
ServletResponseAware, ServletContextAware {
private HttpServletRequest request;
private HttpServletResponse response;
private HttpSession session;
private ServletContext application;
@Override
public void setServletResponse(HttpServletResponse response) { //实现接口的set方法。初始化response
this.response = response;
}
@Override
public void setServletRequest(HttpServletRequest request) {
this.request = request;
}
@Override
public void setServletContext(ServletContext application) {
this.application = application;
}
public String test() throws IOException {
this.session = this.request.getSession();
System.out.println("TestAction4:test");
this.request.setAttribute("name", "学渣");
this.session.setAttribute("name", "学霸");
this.application.setAttribute("name", "学神");
return SUCCESS;
}
}执行结果：
说明：
1.通过实现接口的set方法来实例化request,response,application对象。而TestAction4本身并没有对三个对象进行实例化。session由request.getSession();进行实例化。