31 января, 2017 
rius 
Actually, the task can be split in two subtasks:
— retrieving offset in the form which Vaadin can provide (integer number of milliseconds);
— formatting it so that we could construct ZoneId.
The first part can be handled with:
int offsetInt = getUI().getPage().getWebBrowser().getTimezoneOffset(); |
The second part can be handled this way:
private static final int MILLISECONDS_IN_HOUR = 3_600_000; private static final int MILLISECONDS_IN_MINUTE = 60000; private static final int SECONDS_IN_MINUTE = 60; ... String offset = String.format("%02d:%02d", Math.abs(offsetInt / MILLISECONDS_IN_HOUR), Math.abs((offsetInt / MILLISECONDS_IN_MINUTE) % SECONDS_IN_MINUTE)); offset = (offsetInt >= 0 ? "+" : "-") + offset; ZoneId zoneId = ZoneId.of(offset); |
So, for offset -85*3600*100 milliseconds (-8.5 hours) you are supposed to get «-08:30» which is compliant with ZoneId.of() method.
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