我
使用servlet写一个登录
ChatGPT
以下是使用servlet写一个简单的登录示例:
- 创建一个名为LoginServlet的servlet类,继承HttpServlet类。
- 在doGet()和doPost()方法中编写登录逻辑。
- 在web.xml文件中配置servlet。
示例代码如下:
LoginServlet.java
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("/LoginServlet")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
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("admin123")) {
response.sendRedirect("success.jsp");
} else {
response.sendRedirect("error.jsp");
}
}
}
web.xml
<?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>LoginServlet</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
</web-app>
index.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<form action="LoginServlet" 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>
success.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Success</title>
</head>
<body>
<h1>Login Successful</h1>
</body>
</html>
error.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Error</title>
</head>
<body>
<h1>Login Failed</h1>
</body>
</html>
在浏览器中访问http://localhost:8080/LoginServlet/index.jsp,输入正确的用户名和密码,将会跳转到success.jsp页面,否则跳转到error.jsp页面。
我
ssm框架写一个登录例子
ChatGPT
以下是使用SSM框架写一个简单登录的例子:
- 创建一个名为User的实体类,包含用户名和密码属性。
- 创建一个名为UserMapper的mapper接口,定义查询用户的方法。
- 创建一个名为UserMapper.xml的mapper文件,编写查询用户的SQL语句。
- 创建一个名为UserService的service接口,定义检查用户登录的方法。
- 创建一个名为UserServiceImpl的service实现类,实现UserService接口。
- 创建一个名为UserController的controller类,处理用户登录请求。
- 在web.xml文件中配置DispatcherServlet。
- 创建一个名为login.jsp的登录页面。
示例代码如下:
User.java
public class User {
private String username;
private String password;
// getters and setters
}
UserMapper.java
public interface UserMapper {
User getUserByUsername(String username);
}
UserMapper.xml
<mapper namespace="com.example.mapper.UserMapper">
<select id="getUserByUsername" resultType="com.example.model.User">
select * from user where username=#{username}
</select>
</mapper>
UserService.java
public interface UserService {
boolean checkUser(String username, String password);
}
UserServiceImpl.java
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserMapper userMapper;
@Override
public boolean checkUser(String username, String password) {
User user = userMapper.getUserByUsername(username);
if (user != null && user.getPassword().equals(password)) {
return true;
}
return false;
}
}
UserController.java
@Controller
public class UserController {
@Autowired
private UserService userService;
@RequestMapping("/login")
public String login(HttpServletRequest request) {
String username = request.getParameter("username");
String password = request.getParameter("password");
if (userService.checkUser(username, password)) {
return "success";
} else {
return "error";
}
}
}
web.xml
<web-app>
<display-name>SSM Login Example</display-name>
<!--配置DispatcherServlet-->
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/dispatcherServlet-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
dispatcherServlet-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">
<context:component-scan base-package="com.example.controller" />
<context:component-scan base-package="com.example.service" />
<context:component-scan base-package="com.example.mapper" />
<mvc:annotation-driven />
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/test?useSSL=false" />
<property name="username" value="root" />
<property name="password" value="password" />
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="configLocation" value="classpath:mybatis-config.xml" />
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.example.mapper" />
</bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>
login.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<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>
success.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Success</title>
</head>
<body>
<h1>Login Successful</h1>
</body>
</html>
error.jsp
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Error</title>
</head>
<body>
<h1>Login Failed</h1>
</body>
</html>
在浏览器中访问http://localhost:8080/login.jsp,输入正确的用户名和密码,将会跳转到success.jsp页面,否则跳转到error.jsp页面。
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