【求助】还是连不上mysql

public class test {



  public static void main(String args[]) {

    try {

      /* Test loading driver */

      String driver = "com.mysql.jdbc.Driver";



      System.out.println( "=> loading driver:" );

      Class.forName( driver ).newInstance();

      System.out.println( "OK" );



      /* Test the connection */

      String url = "jdbc:mysql://localhost:3306/coffeebreak";//请问这个端口号用不用写？应该是多少？



      System.out.println( "=> connecting:" );



      java.sql.DriverManager.getConnection(url, "root", "pass" );

      

      System.out.println( "OK" );

    }

    catch( Exception x ) {

      x.printStackTrace();

    }

  }

}

Caused by: java.net.ConnectException: Connection refused: connect

        at java.net.PlainSocketImpl.socketConnect(Native Method)

        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)

        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)

        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)

        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)

        at java.net.Socket.connect(Socket.java:519)

        at java.net.Socket.connect(Socket.java:469)

        at java.net.Socket.<init>(Socket.java:366)

        at java.net.Socket.<init>(Socket.java:209)

        at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.ja

va:256)

        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:276)

        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2027)

        ... 12 more