【javaweb：Servlet】一个用于校验登录信息的servlet demonstration

淩亂°似流年 2022-05-31 23:43 124阅读 0赞

1.servlet程序如下

package indi.login;
    
    import java.io.IOException;
    import java.sql.SQLException;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.apache.commons.dbutils.QueryRunner;
    import org.apache.commons.dbutils.handlers.BeanHandler;
    
    import indi.domain.User;
    import indi.utils.C3P0Utils;
    /**
     * 创建一个用于登录校验的servlet
     * @author Administrator
     *
     */
    public class LoginServlet extends HttpServlet {
    
    	private static final long serialVersionUID = 1L;
    
    	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		//1.从resquest获取登录网页界面提交的用户名和密码
    		String username = (String) request.getParameter("username");
    		String password=(String) request.getParameter("password");
    		//2.从数据库中查询指定用户名和密码的用户
    		//采用C3P0工具类获取datasource
    		QueryRunner queryRunner=new QueryRunner(C3P0Utils.getDataSource());
    		String sql="select * from user where uname=? and upassword=?";
    		User user=null;
    		try {
    			user=queryRunner.query(sql,new BeanHandler<User>(User.class),username,password);
    		} catch (SQLException e) {
    			throw new RuntimeException(e);
    		}
    		//3.判断查询的结果是否为空
    		if(user!=null) {
    			response.getWriter().write(user.toString());
    		}else {
    			response.getWriter().write("sorry! your name or password is wrong!");
    		}
    	}
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doGet(request, response);
    	}
    }

2.html文件如下

<!DOCTYPE html>
    <html>
    <head>
    <meta charset="UTF-8">
    <title>登录提交界面</title>
    </head>
    <body>
    	<form action="/WEB13_Servlet/login" method="post">
    		<input type="text" name="username"><br>
    		<input type="password" name="password"><br>
    		<input type="submit" value="提交">
    	</form>
    </body>
    </html>

3.C3P0连接池配置文件内容如下

<?xml version="1.0" encoding="UTF-8"?>
    <c3p0-config>
    
    	<default-config>
    		<property name="driverClass">com.mysql.jdbc.Driver</property>
    		<property name="jdbcUrl">jdbc:mysql:///web13</property>
    		<property name="user">root</property>
    		<property name="password">root</property>
    		<property name="initialPoolSize">5</property>
    		<property name="maxPoolSize">20</property>
    	</default-config>
    
    	<named-config name="secondname">
    		<property name="driverClass">com.mysql.jdbc.Driver</property>
    		<property name="jdbcUrl">jdbc:mysql:///web08</property>
    		<property name="user">root</property>
    		<property name="password">root</property>
    	</named-config>
    
    
    </c3p0-config>

4.需要用到的类库

![SouthEast][]

[SouthEast]: /images/20220601/0e2a89b8dc3f47aeb125654555ad5ae3.png