db使用timestamp，纳秒信息丢失

• 没有分析，直接看解决方法

private Timestamp convertToUtc(Timestamp localTime) {
    Timestamp utcTimeStamp =  new Timestamp(localTime.getTime() + getLocalToUtcDelta());
    // 补偿丢失的纳秒精度
    utcTimeStamp.setNanos(localTime.getNanos());
    return utcTimeStamp;
}

private long getLocalToUtcDelta() {
    Calendar local = Calendar.getInstance();
    local.clear();
    local.set(1970, Calendar.JANUARY, 1, 0, 0, 0);
    return local.getTimeInMillis();
}