struts2学习笔记（二）——获取登录信息及计算在线人数

  struts2-LoginAndLogout
  
    index.html
    index.htm
    index.jsp
    default.html
    default.htm
    default.jsp
  
  
        struts2
        org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
  

  
       struts2
       /*
  

package com.lewa.action;

import java.util.Map;

import org.apache.struts2.dispatcher.SessionMap;
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.SessionAware;

public class LoginAction implements SessionAware,ApplicationAware{
	
	private static final String SUCCESS = "success";
	
	private static final String LOGOUT="logout";
	//与表单域中的属性相对应
	private String username;
	//JavaBean-style 
	public void setUsername(String username){
		this.username=username;
	}
	
	public String execute(){
		//将用户信息保存到Session中
		//1.获取Session，通过SessionAware接口实现
		
		//2.获取登录信息
		
		//3.把登录信息保存到Session中
		session.put("username", username);
		
		//在线人数 +1
		//1.获取当前在线人数，从Application中获取
		Integer count=(Integer) application.get("count");
		if(count==null){
			count=0;
		}
		
		//使当前在线人数 +1
		count++;
		application.put("count", count);
		return SUCCESS;
	}
	
	public String Logout(){
		//在线人数 -1
		//1.获取在线人数
		Integer count=(Integer) application.get("count");
		
		//2.在在线人数>0的情况下 -1
		if(count!=null && count!=0){
			count--;
			application.put("count", count);
		}
		
		//使Session失效
		((SessionMap)session).invalidate();
		
		return LOGOUT;
	}
	private Map session;
	@Override
	public void setSession(Map session) {
		// TODO Auto-generated method stub
		this.session = session;
	}
	
	private Map application;
	@Override
	public void setApplication(Map application) {
		// TODO Auto-generated method stub
		this.application = application;
	}
}

	
	
	
	
		
		 
		
		
			/login.jsp
		
		
		
		
			/login-success.jsp
		
		
		
		
			/logout-success.jsp
		
	

<%@ page language="java" cOntentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>









      login.jsp

<%@ page language="java" cOntentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>







使用EL
欢迎,${sessionScope.username }





当前在线人数：${applicationScope.count }





使用OGNL和Struts2 标签
欢迎,





当前在线人数：







      logout-success.jsp