HttpServletResponse物件實現請求重定向(四)
阿新 • • 發佈:2018-12-27
(一)請求重定向的概念
1.重定向是指當瀏覽器向Tomcat伺服器傳送請求時,由於一個Servlet1類無法完成所有請求響應工作,這時候Servlet1類會通知瀏覽器重新定向到另一個Servlet2類。瀏覽器再次傳送請求Servlet2,來獲得Servlet2的響應。
(二)使用HttpServletResponse物件實現請求重定向
1.程式碼演示
建立servlet例項
package com.haha;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/LoginDemo")
public class LoginDemo extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username=request.getParameter("username");
String password=request.getParameter("password");
if(("123").equals(username)&&("123").equals(password)){
response.sendRedirect("/ServletDemo/Welcome.html" );
}else{
response.sendRedirect("/ServletDemo/login.html");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
配置Servlet物件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>ServletDemo</display-name>
<servlet>
<servlet-name>login</servlet-name>
<servlet-class>com.haha.LoginDemo</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/wwwppp</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>
建立登入介面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<center>
<form action="/ServletDemo/LoginDemo" method="get">
使用者名稱:<input type="text" name="username" /><br><br>
密 碼:<input type="password" name="password"/><br><br><br>
<input type="submit" value="登入">
<input type="reset" value="重置">
</form>
</center>
</body>
</html>
建立歡迎介面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
歡迎來到魔鬼訓練營
</body>
</html>
2.輸出結果