Why I don't get a connection? Java.. SQL Server Express Edition (server)

Where do I have a bug? A mistake? Why can't I connect? My code,

    package conexiones;
    import java.sql.DriverManager;
    import java.sql.Connection;

    public class miconexion {
        static String db = "futbol";
        static String url = "jdbc:sqlserver://localhost;databaseName="+db+";";

        //(local)\SQLEXPRESS
        //String conn;
        public Connection conn;

        public miconexion() {
            try
            {
                Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                conn=DriverManager.getConnection(url);
  开发者_Go百科              System.out.println("conexion exitosa");
            }
            catch(Exception e)
            {
                System.out.println(e);
                System.out.println("no conectado");
            }
        }

        public Connection getConnection()
        {
            return conn;
        }

        public void desconectar()
        {
            conn=null;
        }

        public static void main(String [] ar )
        {
            miconexion con = new miconexion();
            con.getConnection();
        }
    }

By default MS SQL Server (and probably Express) is not enabled for TCP (JDBC) connections. You need to go into the server configuration and enable TCP.

Since you are using SQL Server Express Edition, try

static String url="jdbc:sqlserver://localhost\\SQLEXPRESS;databaseName="+db+";";

You may need to enable basic authentication. By default MS SQL Server only accepts trusted (aka Windows login) connections. You'll also need to create a user and specify the username and password in the connection string.

If you have liberty to choose on Db driver. Go for JTDS opensource driver for SQL Server.

Connection String example..

jdbc:jtds:<server_type>://<server>[:<port>][/<database>][;<property>=<value>[;...]]

My code can help you, you can connect over 127.0.0.1 on your machine.

sqlserver express connection over servername\instancename

also you should enable tcp/ip in sql configuration, and also enable for ip ( 127.0.0.1)