struts2学习笔记---Action中訪问ServletAPI获取Map类型的Servlet元素
Posted Brenda
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了struts2学习笔记---Action中訪问ServletAPI获取Map类型的Servlet元素相关的知识，希望对你有一定的参考价值。
源码：
strust.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.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="default"> <result>/index.jsp</result> </action> </package> </struts>
success.jsp
<span style="font-size:18px;"><%@ 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></span>
方法一：通过ActionContext来訪问
TestAction1.java
package org.Test.action;
import java.util.Map;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
public class TestAction1 extends ActionSupport {
private Map<String, Object> request;
private Map<String, Object> session;
private Map<String, Object> application;
public TestAction1() {
this.request = (Map)ActionContext.getContext().get("request");
this.session = (Map)ActionContext.getContext().getSession();
this.application = (Map)ActionContext.getContext().getApplication();
}
public String test() {
System.out.println("TestAction1:test");
this.request.put("name", "张三");
this.session.put("name", "李四");
this.application.put("name", "王五");
return SUCCESS;
}
}
执行结果：
说明：
1.TestAction1的
类中：定义Map类型的request,session,application对象
构造方法中：通过ActionContext获取这三个对象
test()方法中：用put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RequestAware,SessionAware, ApplicationAware来訪问
TestAction2.java
package org.Test.action;
import java.util.Map;
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 TestAction2 extends ActionSupport implements RequestAware,
SessionAware, ApplicationAware {
private Map<String, Object> request;
private Map<String, Object> session;
private Map<String, Object> application;
@Override
public void setApplication(Map<String, Object> application) {
this.application = application;
}
@Override
public void setSession(Map<String, Object> session) {
this.session = session;
}
@Override
public void setRequest(Map<String, Object> request) {
this.request = request;
}
public String test() {
System.out.println("TestAction2:test");
this.request.put("name", "小明");
this.session.put("name", "小华");
this.application.put("name", "小王");
return SUCCESS;
}
}执行结果：
说明：
1.把三个set方法传过来的request,session.application值，赋给我们的request,session.application对象。即通过调用set方法来实例化这三个对象，而TestAction2本身并没有对三个对象进行实例化
以上是关于struts2学习笔记---Action中訪问ServletAPI获取Map类型的Servlet元素的主要内容，如果未能解决你的问题，请参考以下文章