登录与会话管理实现-优快云博客

本文链接：https://blog.youkuaiyun.com/thomas0yang/article/details/5930341

1. login.html

LoginServlet .java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class LoginServlet extends HttpServlet{

public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
         String username = request.getParameter("username");
         String password = request.getParameter("password");

         System.out.println("username="+username);
         System.out.println("password="+password);

         response.setContentType("text/html");
         response.getWriter().println("Login susses!!!");
     }
}

2.SetCookie.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class SetCookie extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
    //c1 Cookie 只存在本窗口的内存中，如打开一个新的窗口则不存在
    Cookie c1 = new Cookie("password","123");
    response.addCookie(c1);

    //c2 Cookie 写到客户端C:/Documents and Settings/Administrator/Cookies中，通过设置生命周期，可以做到打开新窗口也可以取出
    Cookie c2 = new Cookie("client_ip",request.getRemoteAddr());
    c2.setMaxAge(60*60);//c2的生命周期为60*60秒
    response.addCookie(c2);


    response.getWriter().println("SetCookie OK!");

}
}

GetCookie.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class GetCookie extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{

    Cookie[] Cookies = request.getCookies();
    for(int i=0;i<Cookies.length;i++){
      Cookie c = Cookies[i];
      response.getWriter().println(c.getName()+","+c.getValue());
    }

}
}

3.SetSession.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class SetSession extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
    HttpSession session = request.getSession(true);//true表示没有session就创建，有就直接拿出来使用
    session.setAttribute("client_ip",request.getRemoteAddr());
    response.getWriter().println("SetSession Ok!");
}
}

GetSession.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class GetSession extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
    HttpSession session = request.getSession(true);//true表示没有session就创建，有就直接拿出来使用
    String ip = (String)session.getAttribute("client_ip");
    response.getWriter().println("client_ip=" + ip);
}
}

4.servlet 生命周期