JSP Cookie案例

项目目录

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
  xmlns="http://java.sun.com/xml/ns/javaee" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>Servlet1</servlet-name>
    <servlet-class>FirstServlet</servlet-class>
  </servlet>
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>SecondServlet</servlet-name>
    <servlet-class>SecondServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Servlet1</servlet-name>
    <url-pattern>/servlet1</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>SecondServlet</servlet-name>
    <url-pattern>/servlet2</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
</web-app>

index.html

这个页面用户输入名字后，提交到了servlet1—>FirstServlet里面

<form action="servlet1" method="get">
    名字:<input type="text" name="userName"/><br/>
    <input type="submit" value="go"/>
</form>

FirstSerlvlet.java

这个页面给用户添加cookie，并且go为获取cookie的链接

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


public class FirstServlet extends HttpServlet {

  public void doGet(HttpServletRequest request, HttpServletResponse response){
  try{

  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
    
  String n=request.getParameter("userName");
  out.print("Welcome "+n);

  Cookie ck=new Cookie("uname",n);//creating cookie object
        response.addCookie(ck);//adding cookie in the response

  //creating submit button
  out.print("<form action='servlet2' method='get'>");
  out.print("<input type='submit' value='go'>");
  out.print("</form>");
    
  out.close();

        }catch(Exception e){System.out.println(e);}
  }
}

SecondServlet.java

获取到cookie的值

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

public class SecondServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response){
  try{

  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  
  Cookie ck[]=request.getCookies();
  out.print("Hello "+ck[0].getValue());

  out.close();

         }catch(Exception e){System.out.println(e);}
  }
  

}