Java UTC 时间

SimpleDateFormat foo = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); System.out.println("foo:"+foo.format(new Date())); Calendar gc = GregorianCalendar.getInstance(); System.out.println("gc.getTime():"+gc.getTime()); System.out.println("gc.getTimeInMillis():"+new Date(gc.getTimeInMillis())); //当前系统默认时区的时间： Calendar calendar=new GregorianCalendar(); System.out.print("时区："+calendar.getTimeZone().getID()+" "); System.out.println("时间："+calendar.get(Calendar.HOUR_OF_DAY)+":"+calendar.get(Calendar.MINUTE)); //美国洛杉矶时区 TimeZone tz=TimeZone.getTimeZone("America/Los_Angeles"); //时区转换 calendar.setTimeZone(tz); System.out.print("时区："+calendar.getTimeZone().getID()+" "); System.out.println("时间："+calendar.get(Calendar.HOUR_OF_DAY)+":"+calendar.get(Calendar.MINUTE)); Date time=new Date(); //1、取得本地时间： java.util.Calendar cal = java.util.Calendar.getInstance(); //2、取得时间偏移量： int zoneOffset = cal.get(java.util.Calendar.ZONE_OFFSET); //3、取得夏令时差： int dstOffset = cal.get(java.util.Calendar.DST_OFFSET); //4、从本地时间里扣除这些差量，即可以取得UTC时间： cal.add(java.util.Calendar.MILLISECOND, -(zoneOffset + dstOffset)); //之后调用cal.get(int x)或cal.getTimeInMillis()方法所取得的时间即是UTC标准时间。 System.out.println("UTC:"+new Date(cal.getTimeInMillis())); Calendar calendar1 = Calendar.getInstance(); TimeZone tztz = TimeZone.getTimeZone("GMT"); calendar1.setTimeZone(tztz); System.out.println(calendar.getTime()); System.out.println(calendar.getTimeInMillis());