一个简单的jsp+servlet实例，实现简单的登录
开发环境eslipse+tomcat8.0
1、先创建Dynamic web project，项目名为RegisterSystem，
2、在WebRoot 目录下创建login.jsp文件，只需修改body中的内容，如下所示：
<body>
<form action="login">
username:<input type="text" name="username"><br>
password:<input type="password" name="pwd"><br>
<input type="submit">
</form>
</body>
3、在scr目录下的com.servlet编写AcountBean.java文件，代码如下：
package com.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;
}
}
4、在scr目录下的com.servlet编写servlet类CheckAccount.java文件，代码如下：
package com.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;
}
}
5、在WebRoot目录下编写success.jsp文件 成功后跳转
<body>
<%
AccountBean account = (AccountBean)session.getAttribute("account");
%>
username:<%= account.getUsername()%>
<br>
password:<%= account.getPassword() %>
</body>
6、在WebRoot目录下编写fail.jsp文件 失败后跳转
<body>
Login Failed!
</body>
7、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>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>CheckAccount</servlet-name>
<servlet-class>com.servlet.CheckAccount</servlet-class> <!-- 这里一定要和类的包路径对应，否则报错-->
</servlet>
<servlet-mapping>
<servlet-name>CheckAccount</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>