JDBC操作数据库实现登录验证

素颜马尾好姑娘i 2023-05-30 13:00 53阅读 0赞

package week01;
    
    import util.JDBCUtils;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.Scanner;
    
    /* * 用户登录验证，解决sql注入问题 * */
    public class demo08 { 
        public static void main(String[] args) { 
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入用户名");
            String username = sc.next();
            System.out.println("请输入密码");
            String password = sc.next();
            boolean logincheck = new demo08().login2(username, password);
            if (logincheck)
                System.out.println("登录成功");
            else
                System.out.println("登录失败");
        }
    
        public boolean login2(String username,String password){ 
            Connection conn = null;
            ResultSet rs = null;
            PreparedStatement pstmt = null;
            if (username == null || password == null){ 
                return false;
            }
    
            try { 
                conn = JDBCUtils.getConnection();
                //定义sql
                String sql = "select * from user where username = ? and password = ?";
                //获取sql对象
                pstmt = conn.prepareStatement(sql);
                //给？赋值
                pstmt.setString(1,username);
                pstmt.setString(2,password);
                //执行sql查询
                rs = pstmt.executeQuery();
    
                if (rs.next())
                    return true;
                else
                    return false;
            } catch (SQLException e) { 
                e.printStackTrace();
            }finally { 
                //释放资源
                JDBCUtils.close(rs,pstmt,conn);
            }
            return false;
        }
    }