将事件添加到日历时，Android Studio将ISO字符串转换为“ America / New_York”

Question

我将字符串“
2018-10-17T22：00：00Z”作为事件添加到日历时尝试将其转换为东部时区，但不是将事件时间添加为6pm，而是将其添加为10pm。任何帮助，将不胜感激。

String[] segments = uri.getPath().split("/");
Date startDate = null;
Date endDate = null;
Activity activity = (Activity) context;
String stTime = "2018-10-17T22:00:00Z";
String enTime = "2018-10-17T23:00:00Z";
String eventTitle = segments[3];
String eventLocation = segments[4];

TimeZone timezone = TimeZone.getTimeZone("America/New_York");

SimpleDateFormat formatStart = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
formatStart.setTimeZone(timezone);

SimpleDateFormat formatEnd = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
formatEnd.setTimeZone(timezone);

try {
    startDate = formatStart.parse(stTime);
    endDate = formatEnd.parse(enTime);
} catch (ParseException e) {
    e.printStackTrace();
}

Calendar calStart = new GregorianCalendar(timezone);
calStart.setTime(startDate);

Calendar calEnd = new GregorianCalendar(timezone);
calEnd.setTime(endDate);


if (ActivityCompat.checkSelfPermission(this.context, android.Manifest.permission.WRITE_CALENDAR) != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(activity, new String[]{android.Manifest.permission.WRITE_CALENDAR},1);
}

Calendar beginTime = Calendar.getInstance();
beginTime.set(calStart.get(Calendar.YEAR), calStart.get(Calendar.MONTH), calStart.get(Calendar.DAY_OF_MONTH), calStart.get(Calendar.HOUR_OF_DAY), calStart.get(Calendar.MINUTE));

Calendar endTime = Calendar.getInstance();
endTime.set(calEnd.get(Calendar.YEAR), calEnd.get(Calendar.MONTH), calEnd.get(Calendar.DAY_OF_MONTH), calEnd.get(Calendar.HOUR_OF_DAY), calEnd.get(Calendar.MINUTE));

ContentResolver cr = context.getContentResolver();
ContentValues values = new ContentValues();
values.put(CalendarContract.Events.DTSTART, beginTime.getTimeInMillis());
values.put(CalendarContract.Events.DTEND, endTime.getTimeInMillis());
values.put(CalendarContract.Events.TITLE, eventTitle);
values.put(CalendarContract.Events.CALENDAR_ID, 1);
values.put(CalendarContract.Events.EVENT_TIMEZONE, "America/New_York");
values.put(CalendarContract.Events.EVENT_LOCATION, eventLocation);

cr.insert(CalendarContract.Events.CONTENT_URI, values);
Toast.makeText(context, "Successfully Added Event", Toast.LENGTH_SHORT).show();

Answer 1

那是因为您要告诉解析器忽略Z，或者说是按字面值匹配，而不是处理它的 意思 。

输入字符串是Instant值，因此解析为Instant， 然后 应用时区。
如果您没有兼容Java
8+的Android，请使用ThreeTenABP。

String stTime = "2018-10-17T22:00:00Z";

ZonedDateTime time = Instant.parse(stTime).atZone(ZoneId.of("America/New_York"));
System.out.println(time); // prints: 2018-10-17T18:00-04:00[America/New_York]

如果您更喜欢使用过时的SimpleDateFormat，只需使用正确的格式，而不指定时区。

SimpleDateFormat formatStart = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
Date startDate = formatStart.parse(stTime);
// My default time zone is America/New_York, so:
System.out.println(startDate); // prints: Wed Oct 17 18:00:00 EDT 2018

startDate.getTime() 是您需要的时间。

对于<24级的API，格式模式X不起作用，因此您需要Z像问题中那样进行硬编码，但是要告诉解析器它采用UTC，因为这就是Z时区的含义。

SimpleDateFormat formatStart = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
formatStart.setTimeZone(TimeZone.getTimeZone("UTC"));
Date startDate = formatStart.parse(stTime);
// My default time zone is America/New_York, so:
System.out.println(startDate); // prints: Wed Oct 17 18:00:00 EDT 2018