jdk8中的一個極其重要的新特性就是增加了對時間操作的api，這是線程安全的類。所以推薦使用。
- LocalDateTime
這是生成年月日時分秒的是一個類。
- LocalDate
這是生成年月日的類。
- LocalTime
生成時分秒。
這幾個類的使用都很方便，但是有一些操作我們需要注意一下。
其中一個是時區問題，如果我們直接使用它們生成時間，他會使用默認的系統時區進行時間生成。
然後我們的mysql使用的時區可能也有對應的問題所以我們在生成時間時應該考慮配置時區：
/**
* Obtains an instance of {@code ZoneId} from an ID ensuring that the
* ID is valid and available for use.
* <p>
* This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}.
* A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'.
* The result will always be a valid ID for which {@link ZoneRules} can be obtained.
* <p>
* Parsing matches the zone ID step by step as follows.
* <ul>
* <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}.
* <li>If the zone ID consists of a single letter, the zone ID is invalid
* and {@code DateTimeException} is thrown.
* <li>If the zone ID starts with '+' or '-', the ID is parsed as a
* {@code ZoneOffset} using {@link ZoneOffset#of(String)}.
* <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId}
* with the same ID and rules equivalent to {@code ZoneOffset.UTC}.
* <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-'
* then the ID is a prefixed offset-based ID. The ID is split in two, with
* a two or three letter prefix and a suffix starting with the sign.
* The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}.
* The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix
* and the normalized offset ID as per {@link ZoneOffset#getId()}.
* The rules of the returned {@code ZoneId} will be equivalent to the
* parsed {@code ZoneOffset}.
* <li>All other IDs are parsed as region-based zone IDs. Region IDs must
* match the regular expression <code>[A-Za-z][A-Za-z0-9~/._+-]+</code>
* otherwise a {@code DateTimeException} is thrown. If the zone ID is not
* in the configured set of IDs, {@code ZoneRulesException} is thrown.
* The detailed format of the region ID depends on the group supplying the data.
* The default set of data is supplied by the IANA Time Zone Database (TZDB).
* This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'.
* This is compatible with most IDs from {@link java.util.TimeZone}.
* </ul>
*
* @param zoneId the time-zone ID, not null
* @return the zone ID, not null
* @throws DateTimeException if the zone ID has an invalid format
* @throws ZoneRulesException if the zone ID is a region ID that cannot be found
*/
public static ZoneId of(String zoneId) {
return of(zoneId, true);
}
這是對應的部分源碼，我們可以傳一個字符串來確定時區。
/**
* A map of zone overrides to enable the short time-zone names to be used.
* <p>
* Use of short zone IDs has been deprecated in {@code java.util.TimeZone}.
* This map allows the IDs to continue to be used via the
* {@link #of(String, Map)} factory method.
* <p>
* This map contains a mapping of the IDs that is in line with TZDB 2005r and
* later, where 'EST', 'MST' and 'HST' map to IDs which do not include daylight
* savings.
* <p>
* This maps as follows:
* <ul>
* <li>EST - -05:00</li>
* <li>HST - -10:00</li>
* <li>MST - -07:00</li>
* <li>ACT - Australia/Darwin</li>
* <li>AET - Australia/Sydney</li>
* <li>AGT - America/Argentina/Buenos_Aires</li>
* <li>ART - Africa/Cairo</li>
* <li>AST - America/Anchorage</li>
* <li>BET - America/Sao_Paulo</li>
* <li>BST - Asia/Dhaka</li>
* <li>CAT - Africa/Harare</li>
* <li>CNT - America/St_Johns</li>
* <li>CST - America/Chicago</li>
* <li>CTT - Asia/Shanghai</li>
* <li>EAT - Africa/Addis_Ababa</li>
* <li>ECT - Europe/Paris</li>
* <li>IET - America/Indiana/Indianapolis</li>
* <li>IST - Asia/Kolkata</li>
* <li>JST - Asia/Tokyo</li>
* <li>MIT - Pacific/Apia</li>
* <li>NET - Asia/Yerevan</li>
* <li>NST - Pacific/Auckland</li>
* <li>PLT - Asia/Karachi</li>
* <li>PNT - America/Phoenix</li>
* <li>PRT - America/Puerto_Rico</li>
* <li>PST - America/Los_Angeles</li>
* <li>SST - Pacific/Guadalcanal</li>
* <li>VST - Asia/Ho_Chi_Minh</li>
* </ul>
* The map is unmodifiable.
*/
這是ZoneId對時區的定義。我們只需傳對應的字符串即可。如：LocalDate.now(ZoneId.of("Asia/Shanghai"))。
最後可能會出現mysql遠程服務器和本地時間相差13個小時的問題，所以我們應該配置一個數據庫的時區
set global time_zone='+08:00';
set time_zone = '+08:00';
至此，解決了兩個時區上的問題