如何在我的web應用程序中添加cookie的代碼

Question

是否有任何代碼可以添加到我的web應用程序中以實現cookie？這正是我可以在web.xml和jsp中完成的方式嗎？我想實現cookies登錄，但我不知道我該如何做到這一點。任何人都可以給我如何實現它的確切指示？

非常感謝您的幫助和支持。

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package my_servlets;

import java.io.IOException; 
import java.io.PrintWriter; 

import javax.servlet.RequestDispatcher; 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import javax.servlet.http.HttpSession; 

import connect_with_my_sql_database.LoginDao; 

import javax.servlet.http.Cookie;

public class Login extends HttpServlet{ 

    private static final long serialVersionUID = 1L; 

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


    } 

    @Override protected void doPost(HttpServletRequest request, HttpServletResponse response)  
      throws ServletException, IOException {  

     response.setContentType("text/html");  
     PrintWriter out = response.getWriter(); 

     String n=request.getParameter("j_Username");  
     String p=request.getParameter("j_Password"); 

     HttpSession session = request.getSession(false); 
     if(session!=null) { 
      session.setAttribute("Username", n); 
      session.setAttribute("Password", p); 
     } 

     if(LoginDao.validate(n, p)){ 

      Cookie c1=new Cookie("j_Username",encrypt(n));//the username and passwrd are //encrypted 
      Cookie c2=new Cookie("j_Password",encrypt(p)); 
      c1.setMaxAge(20000); 
      c2.setMaxAge(20000); 
      response.addCookie(c1); 
      response.addCookie(c2); 

      RequestDispatcher rd=request.getRequestDispatcher("style/success.jsp"); 
      rd.forward(request,response);  
     }  
     else{ 
      //out.print("<p style=\"color:red\">Sorry "+n+" or "+p+" error</p>"); 
      RequestDispatcher rd=request.getRequestDispatcher("style/loginError.jsp");  
      rd.forward(request,response);  
     }  


     out.close();  
    }  
} 

Answer 1

假設有一個login.jsp包含uname和password字段，當我們點擊提交時，控件進入LoginCheck servlet。 LoginCheck會檢查用戶名和密碼是否正確。如果是，它會創建兩個cookie併發送給瀏覽器。

的Login.jsp

<form action="LoginCheck" method="post"> 
<input type="text" name="uname"> 
<input type="pasword" name="password"> 
<input type="submit"> 
</form> 

LoginCheck--的Servlet

public void doPost(HttpServletRequest request,HttpServletResponse response) 
{ 
String uname=request.getParameter("uname"); 
String password=request.getParameter("password"); 
if(checkLogin(uname,password))//checkLogin going to check with database if the user is logged in 
{ 
Cookie c1=new Cookie("uname",encrypt(uname));//the username and passwrd are //encrypted 
Cookie c2=new Cookie("password',encrypt(password)); 
c1.setMaxAge(20000); 
c2.setMaxAge(20000); 
response.addCookie(c1); 
response.addCookie(c2);//sends cookies to the browser 
} 

希望這有助於。