mysql/servlet用户名密码判断是否存在数据库

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mysql/servlet用户名密码判断是否存在数据库

2024-04-09 19:48| 来源: 网络整理| 查看: 265

数据库连接类:

package com.xasmall.test; import java.io.IOException; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.Properties; /** * 数据库连接类 * @author 26248 * */ public class DBUTtil { public static Connection jdbaload() { Properties prop=new Properties(); Connection conn=null; try { prop.load(DBUTtil.class.getClassLoader().getResourceAsStream("config.properties")); } catch (IOException e1) { System.out.println("文件为读取成功!"); } String url=prop.getProperty("url"); String driver=prop.getProperty("driver"); String user=prop.getProperty("user"); String password=prop.getProperty("password"); try { Class.forName(driver); conn=DriverManager.getConnection(url, user, password); } catch (ClassNotFoundException e) { System.out.println("未加载mysql驱动!"); } catch (SQLException e) { System.out.println("未连接mysql!"); } if(conn!=null) { return conn; } else { throw new Error("数据库连接错误!"); } } }

用户属性类:

package com.xasmall.test; /** * 用户属性类 * @author 26248 * */ public class User { private int id; private String name; private String password; /** * @return the id */ public int getId() { return id; } /** * @param id the id to set */ public void setId(int id) { this.id = id; } /** * @return the name */ public String getName() { return name; } /** * @param name the name to set */ public void setName(String name) { this.name = name; } /** * @return the password */ public String getPassword() { return password; } /** * @param password the password to set */ public void setPassword(String password) { this.password = password; } }

抽象接口类(方法):

package com.xasmall.test; /** * @author 26248 * */ public interface UserDAO { //创建一个login方法 public User login(String name,String password); }

实现接口类:

package com.xasmall.test; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; /**实现UserDAO接口 * @author 26248 * */ public class UserDAOImpl implements UserDAO{ @Override public User login(String name, String password) { User user=new User(); Connection co=DBUTtil.jdbaload(); String sql="select id,username,password from student where username=? and password=?"; try { PreparedStatement pstm=co.prepareStatement(sql); pstm.setString(1, name); pstm.setString(2, password); ResultSet rs=pstm.executeQuery(); if(rs.next()) { user.setId(rs.getInt(1)); user.setName(name); user.setPassword(password); return user; } else return null; } catch (SQLException e) { System.out.println("sql语句错误!"); } return null; } }

表单(jsp):

Insert title here 欢迎来到登陆页面 Username: Password:

数据库属性文件(properties): driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/? user=root password=?

判断操作类:

package com.xasmall.test; 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(urlPatterns= {"/MyLogin"}) public class MyLogin extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { UserDAO user=new UserDAOImpl(); User userLogin=user.login(request.getParameter("username"), request.getParameter("password")); if(userLogin==null) { System.out.println("数据库中不存在用户名密码!"); } else { System.out.println("username:"+userLogin.getName()+"password"+userLogin.getPassword()); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }

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mysql/servlet用户名密码判断是否存在数据库

mysql/servlet用户名密码判断是否存在数据库

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