一個簡單的jsp+servlet實例，實現簡單的登陸

時間 2020-09-20

標籤一個簡單 jsp+servlet jsp servlet 實例實現登陸欄目 JSP 简体版

原文原文鏈接

開發環境myeclipse+tomcat5.5html

1、先建立web project

在菜單欄選File->New->Web->Dynamic Web Projectjava

Project name我命名爲JavaWebTest01 （能夠隨便起）web

Target runTime 選咱們以前tomcat配置的版本。瀏覽器

一直NEXT到Finishtomcat

二.新建jsp頁面

一、在WebContent下新建一個jsp頁面（若是列表裏沒有jsp選項，到other裏去找）服務器

這裏我給jsp頁面的名字命爲welcome，點擊Finish，而後再body中修改以下內容：session

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="gbk"%>
<%@ page language="java" import="com.servlet.*"%>app

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
Acount account = (Acount)session.getAttribute("account");
%>
<h2>
Welcome to "<%= account.getUsername()%>" Login System!
</h2>
This is the first javaWeb Project!
</body>
</html>eclipse

二、建立login.jsp文件，只需修改body中的內容，以下所示：jsp

<body>
    <form action="login">
    username:<input type="text" name="username"><br>
    password:<input type="password" name="pwd"><br>
    <input type="submit">
    </form>
  </body>

三、在scr目錄下的com.ht.servlet編寫AcountBean.java文件，代碼以下：

package com.ht.servlet;

public class AccountBean {
private String username = "";
private String password = "";
public String getPassword() {
  return password;
}
public void setPassword(String password) {
  this.password = password;
}
public String getUsername() {
  return username;
}
public void setUsername(String username) {
  this.username = username;
}
}

四、在scr目錄下的com.ht.servlet編寫servlet類CheckAccount.java文件，代碼以下：

package com.ht.servlet;

import java.io.IOException;

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 CheckAccount extends HttpServlet {

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doGet(req,resp);
}

@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
   throws ServletException, IOException {
  HttpSession session = req.getSession();
  AccountBean account = new AccountBean();
  String username = req.getParameter("username");
  String pwd = req.getParameter("pwd");
  account.setPassword(pwd);
  account.setUsername(username);
  if((username != null)&&(username.trim().equals("jsp"))) {
   if((pwd != null)&&(pwd.trim().equals("1"))) {
    System.out.println("success");
    session.setAttribute("account", account);
    String login_suc = "success.jsp";
    resp.sendRedirect(login_suc);
    return;
   }
  }
  String login_fail = "fail.jsp";
  resp.sendRedirect(login_fail);
  return;
}

}
五、在WebRoot目錄下編寫success.jsp文件成功後跳轉

<body>
    <%
    AccountBean account = (AccountBean)session.getAttribute("account");
    %>
    username:<%= account.getUsername()%>
     <br>
     password:<%= account.getPassword() %>
  </body>

六、在WebRoot目錄下編寫fail.jsp文件失敗後跳轉

<body>
Login Failed! <br>
</body>

說明：在success.jsp文件中用到了AccountBean中的getUsername()方法，因此須要在頁面頭上添加包名的命名空間，以下

<%@ page language="java" import="com.ht.servlet.*"%> ，而後才能在頁面上使用username:<%= account.getUsername()%>這種方式訪問。

七、修改web.xml配置文件

<?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">
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>

  <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>CheckAccount</servlet-name>
       <servlet-class>com.ht.servlet.CheckAccount</servlet-class>
     </servlet>