sessionmanager.java

主要是航空预订系统

package com.air.util;

import javax.servlet.http.HttpServletRequest;

import com.air.constants.AppConstants;
import com.air.model.LoginUser;
import com.air.pojo.SessionData;

public final class SessionManager
{
	private SessionManager()
	{
	}
	private static class SessionManagerHolder
	{
		static final SessionManager sessionmm = new SessionManager();
	}
	/**
	 * @return an instance of SessionManager
	 */
	public static SessionManager getInstance()
	{
		return SessionManagerHolder.sessionmm;
	}
	public SessionData getSessiondata(HttpServletRequest request)
	{
		SessionData sessiondata = (SessionData)request.getSession().getAttribute(AppConstants.SESSION_DATA);
		if(sessiondata == null)
		{
			sessiondata = new SessionData();
			setSessiondata(request, sessiondata);
		}
		return sessiondata;
	}
	public void setSessiondata(HttpServletRequest request, SessionData sessiondata)
	{
		request.getSession().setAttribute(AppConstants.SESSION_DATA, sessiondata);
	}
	public boolean isTimeOut(HttpServletRequest request)
	{
		return request.getSession().getAttribute(AppConstants.SESSION_DATA) == null;
	}
	
	public LoginUser getSessionUser(HttpServletRequest request)
	{
		return getSessiondata(request).getLoginuser();
	}
	public void setSessionUser(HttpServletRequest request, LoginUser loginuser)
	{
		getSessiondata(request).setLoginuser(loginuser);
	}
	public void invalidateSession(HttpServletRequest request)
	{
		setSessiondata(request, null);
		request.getSession().invalidate();
	}
	public String getSessionUserid(HttpServletRequest request)
	{
		String retval = AppConstants.EMPTY_STR;
		LoginUser user = getSessiondata(request).getLoginuser();
		if( user != null )
		{
			retval = user.getUsername();
		}
		return retval;
	}
}