Java displays current time in Los Angeles, USA

The code copy is as follows:

SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

Calendar calendar = Calendar.getInstance();

sdf.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));

System.out.println("Los_Angeles :"+sdf.format(calendar.getTime()));

sdf.setTimeZone(TimeZone.getTimeZone("Asia/Shanghai"));

System.out.println("Shanghai: "+sdf.format(calendar.getTime()));