将自定义区域设置日期时间转换为android中的gmt

Question

我正在尝试将在Android设备上的区域设置时创建的日期时间格式转换为GMT。我无法获得正确的值。而且生成的dateTime是针对android的本地时间。如何将其转换为精确的GMT unixtime？

         String dateTime="02-02-2016 8:28 PM";
  SimpleDateFormat format = new SimpleDateFormat("dd-MM-yyyy hh:mm a");
            format.setTimeZone(TimeZone.getTimeZone("GMT"));
            Date date = null;
            try {
                date = format.parse(dateTime);
                System.out.println("Date ->" + date);
            } catch (Exception e) {
                e.printStackTrace();
            }
            long unixtime = date.getTime() / 1000;

Answer 1

try{
                    SimpleDateFormat sourceFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    sourceFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
                    Log.v("Current time", ""+ sourceFormat.format(new Date()));

                    Date parsed = sourceFormat.parse(sourceFormat.format(new Date())); // => Date is in UTC now


                    TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
                    SimpleDateFormat destFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    destFormat.setTimeZone(tz);

//                  String result = destFormat.format(parsed);
                    String result = destFormat.format(sourceFormat.parse(sourceFormat.format(new Date())));

                    Log.e("result", ""+result);


//                  2015-11-26 02:07:59                 
                    SimpleDateFormat UTCFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    SimpleDateFormat severFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    SimpleDateFormat localFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

                    UTCFormat.setTimeZone(TimeZone.getTimeZone("UTC"));

                    TimeZone tz1 = TimeZone.getTimeZone("America/Los_Angeles");
                    severFormat.setTimeZone(tz1);

                    localFormat.setTimeZone(TimeZone.getDefault());

                    Date serverDate = severFormat.parse(result);
                    Date utcDate =  UTCFormat.parse(UTCFormat.format(serverDate));

                    String localDate = localFormat.format(utcDate);
                    Log.e("localDate", ""+localDate);
                }catch(ParseException e){
                    e.printStackTrace();
                } catch (java.text.ParseException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }