用javaweb编写一个登录网页
时间: 2023-09-19 11:06:20 浏览: 37
以下是一个简单的登录网页的示例,使用Java Servlet和JSP技术:
index.jsp:
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<h1>Login</h1>
<form action="login" method="post">
<label>Username:</label>
<input type="text" name="username"><br>
<label>Password:</label>
<input type="password" name="password"><br>
<input type="submit" value="Login">
</form>
</body>
</html>
```
LoginServlet.java:
```
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 LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public LoginServlet() {
super();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
if(username.equals("admin") && password.equals("password")) {
HttpSession session = request.getSession();
session.setAttribute("username", username);
response.sendRedirect("welcome");
} else {
response.sendRedirect("error");
}
}
}
```
welcome.jsp:
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Welcome</title>
</head>
<body>
<h1>Welcome, <%= session.getAttribute("username") %>!</h1>
<p>You have successfully logged in.</p>
</body>
</html>
```
error.jsp:
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Error</title>
</head>
<body>
<h1>Error</h1>
<p>Invalid username or password.</p>
</body>
</html>
```
在web.xml中配置servlet和jsp:
```
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>WelcomeServlet</servlet-name>
<url-pattern>/welcome</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>ErrorServlet</servlet-name>
<url-pattern>/error</url-pattern>
</servlet-mapping>
```
此示例假设存在名为“admin”的用户,密码为“password”。如果用户输入正确的用户名和密码,他们将被重定向到“welcome”页面,否则他们将被重定向到“error”页面。在“welcome”页面上,它会欢迎用户并显示他们的用户名。