给定以下单元测试:
@Test
public void zonedDateTimeCorrectlyRestoresItself() {
// construct a new instance of ZonedDateTime
ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Z"));
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3820} "Z"
String converted = now.toString();
// restore an instance of ZonedDateTime from String
ZonedDateTime restored = ZonedDateTime.parse(converted);
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3820} "Z"
assertThat(now).isEqualTo(restored); // ALWAYS succeeds
}
@Test
public void jacksonIncorrectlyRestoresZonedDateTime() {
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.findAndRegisterModules();
objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
// construct a new instance of ZonedDateTime
ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Z"));
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3820} "Z"
String converted = objectMapper.writeValueAsString(now);
// restore an instance of ZonedDateTime from String
ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3821} "UTC"
assertThat(now).isEqualTo(restored); // NEVER succeeds
}
这个解决方法:
@Test
public void usingDifferentComparisonStrategySucceeds() throws Exception {
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.findAndRegisterModules();
objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
// construct a new instance of ZonedDateTime
ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Z"));
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3820} "Z"
String converted = objectMapper.writeValueAsString(now);
// restore an instance of ZonedDateTime from String
ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
// offset = {ZoneOffset@3820} "Z"
// zone = {ZoneOffset@3821} "UTC"
// the comparison succeeds when a different comparison strategy is used
// checks whether the instants in time are equal, not the java objects
assertThat(now.isEqual(restored)).isTrue();
}
我想我想弄清楚为什么 Jackson 内部不调用 ZonedDateTime.parse()
?我个人认为这是 Jackson 的一个错误,但我还没有足够的信心在没有任何反馈的情况下为它打开一个问题。
最佳答案
引用维基百科 ISO 8601 :
If the time is in UTC, add a
Z
directly after the time without a space.Z
is the zone designator for the zero UTC offset."09:30 UTC"
is therefore represented as"09:30Z"
or"0930Z"
."14:45:15 UTC"
would be"14:45:15Z"
or"144515Z"
.UTC time is also known as Zulu time, since Zulu is the NATO phonetic alphabet word for Z.
Z
不是区域。 UTC
是区域,然后在格式化字符串中使用 Z
表示。
永远不要使用 ZoneId.of("Z")
。这是错误的。
关于java - 通过 Jackson 的 ZonedDateTime 往返产生不相等的 ZonedDateTime,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44372498/