分别写好登录页、主页、主页的几个功能页、登录失败页、servlet用作登录和退出处理，filter用于登录拦截处理和编码处理。
登录页：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
body{
text-align:center;
}
登录
主页：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@page import="java.text.SimpleDateFormat"%>
<%@page import="java.util.Calendar"%>
#container{
margin: 0px;
padding: 0px;
border:1px solid ;
height:125px;
font-size:25px;
background: -moz-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#DDDDDD ), color-stop(100%,#E0FFFF));
background: -webkit-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: -o-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -ms-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: linear-gradient(to bottom, #DDDDDD 0%,#E0FFFF 100%);
}
#left{
margin: 0px;
padding: 0px;
height:330px;
width: 30%;
float: left;
border:1px solid black;
font-size:25px;
background: -moz-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#DDDDDD ), color-stop(100%,#E0FFFF));
background: -webkit-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: -o-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -ms-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: linear-gradient(to bottom, #DDDDDD 0%,#E0FFFF 100%);
}
#right{
margin: 0px;
padding: 0px;
height:330px;
float: rigth;
border:1px solid black;
background: -moz-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#DDDDDD ), color-stop(100%,#E0FFFF));
background: -webkit-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: -o-linear-gradient(top, #DDDDDD 0%, #E0FFFF 100%);
background: -ms-linear-gradient(top, #DDDDDD 0%,#E0FFFF 100%);
background: linear-gradient(to bottom, #DDDDDD 0%,#E0FFFF 100%);
}
}@charset "UTF-8";
<%
String id=(String)session.getAttribute("id");
%>
当前在线人数：
<%--
Object num=application.getAttribute("count");
if(num==null){
out.print(0);
}else{
out.println(num);
}
--%>
<%
Object num=application.getAttribute("count");
out.println(num);
%>
[<%=id %>]你好！
<%
Calendar now = Calendar.getInstance();
int year = now.get(Calendar.YEAR);
int month = now.get(Calendar.MONTH) + 1;
int day = now.get(Calendar.DAY_OF_MONTH);
int week = now.get(Calendar.DAY_OF_WEEK) - 1;
String[] Week = {"一","二","三","四","五","六","日"};
out.print("当前时间："+year+"年"+month+"月"+day+"日，星期"+Week[week-1]);
SimpleDateFormat format=new SimpleDateFormat(" HH:mm:ss");
out.print(format.format(now.getTime()));
%>
菜单
用户管理
新闻管理
修改密码
登录处理：
package myServlet;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/exam_3_loginservlet")
public class exam_3_loginservlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public exam_3_loginservlet() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
HttpSession session=request.getSession();
ServletContext application=request.getServletContext();
String id=request.getParameter("id");
String password=request.getParameter("pass");
if(id.equals("123")&&password.equals("123")){
session.setAttribute("id", id);
Integer count = (Integer)application.getAttribute("count");
if(count==null){
application.setAttribute("count", 1);
}else{
application.setAttribute("count", count+1);
}
response.sendRedirect("exam_3_index.jsp");
}else{
response.sendRedirect("exam_3_loginfail.jsp");
}
doGet(request, response);
}
}
退出处理：
package myServlet;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/exam_3_exitservlet")
public class exam_3_exitservlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public exam_3_exitservlet() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
HttpSession session=request.getSession();
ServletContext application=request.getServletContext();
session.setAttribute("id", null);
Integer count = (Integer)application.getAttribute("count");
application.setAttribute("count", count-1);
response.sendRedirect("exam_3_login.jsp");
doGet(request, response);
}
}
登录拦截：
package filter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
@WebFilter({ "/exam_3_index.jsp", "/exam_3_news.jsp", "/exam_3_yonghuguanli.jsp", "/exam_3_changepass.jsp","/exam_3_loginfail.jsp" })
public class exam_3_filter implements Filter {
public exam_3_filter() {
// TODO Auto-generated constructor stub
}
public void destroy() {
// TODO Auto-generated method stub
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
// TODO Auto-generated method stub
// place your code here
PrintWriter out = response.getWriter();
HttpSession session = ((HttpServletRequest) request).getSession();
String id = (String) session.getAttribute("id");
if(id==null) {
out.print("没有登录，请登录");
return;
}
// pass the request along the filter chain
chain.doFilter(request, response);
}
public void init(FilterConfig fConfig) throws ServletException {
// TODO Auto-generated method stub
}
}
