DB的封装

public class DB
{
    
    public static Connection getConn()
    {
        Connection conn=null;
        try
        {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/bbs", "root", "root");
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return conn;
    }
    
    public static Statement getStatement(Connection conn)
    {
        Statement stmt=null;
        try
        {
            stmt=conn.createStatement();
        }
        catch (SQLException e)
        {
            e.printStackTrace();
        }
        return stmt;
    }
    
    public static ResultSet executeQuery(Statement stmt,String sql)
    {
        ResultSet rs=null;
        try
        {
            rs=stmt.executeQuery(sql);
        }
        catch (SQLException e)
        {
            e.printStackTrace();
        }
        return rs;
    }
    
    public static void close(Connection conn)
    {
        if(conn != null)
            try
            {
                conn.close();
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
    }
    
    public static void close(Statement stmt)
    {
        if(stmt != null)
            try
            {
                stmt.close();
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
    }
    
    public static void close(ResultSet rs)
    {
        if(rs != null)
            try
            {
                rs.close();
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
    }
}