Servlet之Cookie相關操作
阿新 • • 發佈：2019-01-08
這裡主要講解cookie的新增和讀取
工程中涉及到的servlet的配置
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" 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_3_0.xsd"> <display-name></display-name> <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>AServlet</servlet-name> <servlet-class>AServlet</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>BServlet</servlet-name> <servlet-class>BServlet</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>CServlet</servlet-name> <servlet-class>CServlet</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>DServlet</servlet-name> <servlet-class>DServlet</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>LoginServlet</servlet-name> <servlet-class>LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AServlet</servlet-name> <url-pattern>/a</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>BServlet</servlet-name> <url-pattern>/b</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>CServlet</servlet-name> <url-pattern>/c</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>DServlet</servlet-name> <url-pattern>/d</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/loginServlet</url-pattern> </servlet-mapping> </web-app>
會話session屬性的設定與讀取
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class AServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); HttpSession session=request.getSession(); session.setAttribute("name", "李婉琳"); request.getRequestDispatcher("b").forward(request, response); // response.sendRedirect("/web/b"); } }
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class BServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); System.out.println("session : "+request.getSession().getAttribute("name")); request.getRequestDispatcher("/index.jsp").forward(request, response); } }
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
name:
<%=session.getAttribute("name") %>
</body>
</html>
import java.io.IOException;
import java.io.PrintWriter;
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 CServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Cookie cookie=new Cookie("p1", "v1");
cookie.setMaxAge(10);
response.addCookie(cookie);
request.getRequestDispatcher("d").forward(request, response);
}
}
import java.io.IOException;
import java.io.PrintWriter;
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 DServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Cookie[] cookies=request.getCookies();
for(Cookie cookie:cookies){
System.out.println("**********************************");
System.out.println("cookie name : "+cookie.getName());
System.out.println("cookie value : "+ cookie.getValue());
System.out.println("----------------------------------");
}
}
}
通過cookie儲存登入資訊
import java.io.IOException;
import java.io.PrintWriter;
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 LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String username=request.getParameter("username");
String password=request.getParameter("password");
Cookie cookie1=new Cookie("username", username);
Cookie cookie2=new Cookie("password", password);
response.addCookie(cookie1);
response.addCookie(cookie2);
}
}
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>My JSP 'login.jsp' starting page</title>
</head>
<body>
<%
Cookie[] cookies = request.getCookies();
String username = "";
String password = "";
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookie.getName() != null
&& cookie.getName().equals("username")) {
username = cookie.getValue();
}
if (cookie.getName() != null
&& cookie.getName().equals("password")) {
password = cookie.getValue();
}
}
}
%>
<form action="loginServlet">
<input type="text" name="username" value="<%=username%>" /><br>
<input type="password" name="password" value="<%=password%>" /><br>
<input type="submit" value="提交" />
</form>
</body>
</html>