The following code:

$ cat TZTest.java
import java.io.*;
import java.util.*;

public class TZTest {

  TZTest() {

    TimeZone time_zone = TimeZone.getDefault();

    System.out.println("The current time is :" + new Date());
    System.out.println("The timezone is "+time_zone.getID());

    if (time_zone.inDaylightTime(new Date()))
        System.out.println("in Daylight time");
    else
        System.out.println("not in Daylight time");

    if (time_zone.useDaylightTime())
        System.out.println("use Daylight time");
    else
        System.out.println("not use Daylight time");

    System.out.println("Raw offset in seconds: "+time_zone.getRawOffset());
    System.out.println("Raw offset in hours: "+
      time_zone.getRawOffset()/(1000*60*60));

    GregorianCalendar gc = new GregorianCalendar();
    gc.setTime(new Date());
    System.out.println("DST offset in seconds: "+
      time_zone.getOffset(gc.AD, gc.get(gc.YEAR), gc.get(gc.MONTH),
        gc.get(gc.DAY_OF_MONTH), gc.get(gc.DAY_OF_WEEK), 0));
    System.out.println("DST offset in hours: "+
      time_zone.getOffset(gc.AD, gc.get(gc.YEAR), gc.get(gc.MONTH),
        gc.get(gc.DAY_OF_MONTH), gc.get(gc.DAY_OF_WEEK), 0)/(1000*60*60));
         
  }
  
  public static void main(String argv[]) {
    new TZTest();
  }
}

returns an incorrect value for getOffset(). DST is ignored.