记录最后访问时间,验证码校验(session)

记录最后访问时间

package com.name.session;

import java.io.IOException;
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;

public class session extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {	
		//解决乱码问题
		response.setContentType("text/html;charset=utf-8");
		
		//获取当前的时间
		SimpleDateFormat sdf=new SimpleDateFormat();
		Date d=new Date();
		String s=sdf.format(d);
		
		//获取已存在的cookie
		Cookie[] cookies = request.getCookies();
		//存放取出的Cookie
		Cookie ck=null;
		//判断是否有访问记录
		if(cookies!=null){
			for(Cookie cookie:cookies){
				if("lasttime".equals(cookie.getName())){
					//如果有记录,就存放到ck中
					ck=cookie;
				}
			}
		}		
		//判断ck是否为空
		if(ck!=null){
			response.getWriter().println("欢迎再次回来,上次访问时间"+ ck.getValue());
		}else{
			response.getWriter().println("欢迎访问,当前时间"+s);
		}
		
		//把当前时间放入cookie中
		Cookie cookie = new Cookie("lasttime", s);
		//写回到浏览器
		response.addCookie(cookie);
		//设置cookie保存时间,比如3600秒
		cookie.setMaxAge(3600);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		doGet(request, response);
	}

}

验证码校验(session)

总结一下从CodeServlet里拿,需要用到session

第三方写的验证码的代码,拿来用就可以了