package day01.cookies;import java.io.IOException;import java.net.URLDecoder;import java.net.URLEncoder;import java.text.SimpleDateFormat;import java.util.Date;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 记录用户上次访问的时间 *  * @author mzy * */public class LastTimeServlet extends HttpServlet {	private static final long serialVersionUID = 613621422104403409L;	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {		request.setCharacterEncoding("utf-8");		response.setContentType("text/html;charset=utf-8");				Cookie[] cookies = request.getCookies();		String lastTime = null;				SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日hh时mm分ss秒");		String nowTime = sdf.format(new Date());				if(cookies != null) {			for(Cookie cookie : cookies) {				if("lastTime".equals(cookie.getName())) {					response.getWriter().write("欢迎您再次访问本站，当前时间为："+nowTime+"
");					lastTime = cookie.getValue();					response.getWriter().write("您上次访问的时间为："+URLDecoder.decode(lastTime, "utf-8"));										// Cookie c = new Cookie("lastTime", URLEncoder.encode(nowTime, "utf-8"));					// response.addCookie(c);					cookie.setValue(URLEncoder.encode(nowTime, "utf-8"));					response.addCookie(cookie);										break;				}			}					}		// cookie虽然不为空，但是并没有我们需要的lastTime数据		if(cookies == null || lastTime == null ) {			response.getWriter().write("欢迎您首次访问本站，当前的时间为："+nowTime);						// 并不需要lastTime数据，因为我们得到lastTime实际是从cookie中获取的			// lastTime = nowTime;						Cookie c =  new Cookie("lastTime", URLEncoder.encode(lastTime, "utf-8"));			response.addCookie(c);		}			}	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {				response.setContentType("text/html");		}}