MySQL第三天

//连接数据库的工具类
public class JDBCUtils {
    private static final String USER="root";
    private static final String PWD="root";
    private static final String URL="jdbc:mysql://localhost:3306/girl";
    private static final String DRIVER="com.mysql.jdbc.Driver";
    //1.注册驱动
    static {
        try {
            Class.forName(DRIVER);
        } catch (Exception e){
            e.printStackTrace();
        }
    }
    //2.得到数据库连接
    public static Connection getConnetion() throws SQLException{
        return (Connection) DriverManager.getConnection(URL,USER,PWD);
    }
    //3.关闭资源
    public static void close(Connection con, Statement stat){
        if(stat!=null){
            try {
                stat.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(con!=null){
            try {
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    public static void close(Connection con, Statement stat,ResultSet rs){
        if (rs!=null){
            try {
                rs.close();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        if(stat!=null){
            try {
                stat.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(con!=null){
            try {
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
//登陆实现

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入用户名");
    String name= sc.nextLine();
    System.out.println("请输入密码");
    String password=sc.nextLine();
    login(name,password);
}
//1.写一个登陆方法
public static void login(String name,String password){
    Connection con = null;
    Statement stat= null;
    ResultSet rs= null;
    try {
        //1.通过工具类获得链接
        con= JDBCUtils.getConnetion();
        //2.定义sql
        String sql ="select*from yang where ename='"+name+"'and mgr ='"+password+"'";
        //3.获取执行对象
        stat=con.createStatement();
        System.out.println(sql);
        //4.查询数据库  如果有记录 表示登录成功  否则登录失败
        rs=stat.executeQuery(sql);
        if (rs.next()){
            System.out.println("登陆成功");
        }else {
            System.out.println("登陆失败");
        }
    } catch (Exception e){
        e.printStackTrace();
    }finally {
       JDBCUtils.close(con,stat,rs);
    }
}

转载于:https://www.cnblogs.com/Y-mmeng/p/10673077.html