How can I display the current time as GMT?

Create a custom TimeZone and use it for DateFormat.setTimeZone(). This is discussed briefly in the API documentation and shown in the following code.

import java.text.*;
import java.util.*;

public class GMTFmt2
{

  public static void main( String[] args )
  {

    TimeZone tz = TimeZone.getTimeZone("GMT:00");

    DateFormat dfGMT = DateFormat.getTimeInstance( DateFormat.LONG );
    dfGMT.setTimeZone( tz );

    System.out.println( dfGMT.format( new Date() ) );

  } // end main

}  // End class GMTFmt2