公历的默认构造函数使用计算机的本地时区.如果这不同于UTC，则会出现此现象.尝试使用GregorianCalendar(TimeZone)构造函数并将UTC传递给该构造函数.

The default constructor of the Gregorian Calendar uses the local timezone of the machine. If that's different from UTC, you get this behavior. Try to use the GregorianCalendar(TimeZone) constructor and pass UTC into that.

这将起作用:

public void testParseDate() throws Exception {

    TimeZone UTC = TimeZone.getTimeZone("UTC");

    // Create a UTC formatter
    final SimpleDateFormat formatter = new SimpleDateFormat(
            "yyyy-MM-dd HH:mm:ss z");
    formatter.setTimeZone(UTC);

    // Create a UTC Gregorian Calendar (stores internally in UTC, so
    // get(Calendar.HOUR_OF_DAY) returns in UTC instead of in the
    // local machine's timezone.
    final Calendar c = new GregorianCalendar(UTC);

    // Ask the formatter for a date representation and pass that
    // into the GregorianCalendar (which will convert it into
    // it's internal timezone, which is also UTC.
    c.setTime(formatter.parse("2013-03-02 11:59:59 UTC"));

    // Output the UTC hour of day
    assertEquals(11, c.get(Calendar.HOUR_OF_DAY));
}