我能够通过对 Accessing Data with MongoDB 的官方 Spring Boot 指南进行最小修改来重现我的问题,见 https://github.com/thokrae/spring-data-mongo-zoneddatetime .
将 java.time.ZonedDateTime
字段添加到 Customer 类后,运行指南中的示例代码失败并出现 CodecConfigurationException:
客户.java:
public String lastName;
public ZonedDateTime created;
public Customer() {
输出:
...
Caused by: org.bson.codecs.configuration.CodecConfigurationException`: Can't find a codec for class java.time.ZonedDateTime.
at org.bson.codecs.configuration.CodecCache.getOrThrow(CodecCache.java:46) ~[bson-3.6.4.jar:na]
at org.bson.codecs.configuration.ProvidersCodecRegistry.get(ProvidersCodecRegistry.java:63) ~[bson-3.6.4.jar:na]
at org.bson.codecs.configuration.ChildCodecRegistry.get(ChildCodecRegistry.java:51) ~[bson-3.6.4.jar:na]
这可以通过在 pom.xml 中将 Spring Boot 版本从 2.0.5.RELEASE 更改为 2.0.1.RELEASE 来解决:
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
</parent>
现在异常消失了,客户对象包括 ZonedDateTime 字段 are written to MongoDB .
我向 spring-data-mongodb 项目提交了一个错误 (DATAMONGO-2106),但如果不希望更改此行为也没有高优先级,我会理解。
最好的解决方法是什么?在处理异常消息时,我发现了几种方法,例如注册 custom codec , 一个 custom converter或使用 Jackson JSR 310 .我宁愿不向我的项目添加自定义代码来处理 java.time 包中的类。
最佳答案
Spring Data MongoDB 从不支持带有时区的日期时间类型,正如 Oliver Drotbohm 本人在 DATAMONGO-2106 中所述.
这些是已知的解决方法:
- 使用不带时区的日期时间类型,例如java.time.Instant。 (通常建议只在后端使用 UTC,但我必须扩展现有的代码库,该代码库采用不同的方法。)
编写一个自定义转换器并通过扩展 AbstractMongoConfiguration 来注册它。见分行converter在我的测试存储库中运行示例。
@Component @WritingConverter public class ZonedDateTimeToDocumentConverter implements Converter<ZonedDateTime, Document> { static final String DATE_TIME = "dateTime"; static final String ZONE = "zone"; @Override public Document convert(@Nullable ZonedDateTime zonedDateTime) { if (zonedDateTime == null) return null; Document document = new Document(); document.put(DATE_TIME, Date.from(zonedDateTime.toInstant())); document.put(ZONE, zonedDateTime.getZone().getId()); document.put("offset", zonedDateTime.getOffset().toString()); return document; } } @Component @ReadingConverter public class DocumentToZonedDateTimeConverter implements Converter<Document, ZonedDateTime> { @Override public ZonedDateTime convert(@Nullable Document document) { if (document == null) return null; Date dateTime = document.getDate(DATE_TIME); String zoneId = document.getString(ZONE); ZoneId zone = ZoneId.of(zoneId); return ZonedDateTime.ofInstant(dateTime.toInstant(), zone); } } @Configuration public class MongoConfiguration extends AbstractMongoConfiguration { @Value("${spring.data.mongodb.database}") private String database; @Value("${spring.data.mongodb.host}") private String host; @Value("${spring.data.mongodb.port}") private int port; @Override public MongoClient mongoClient() { return new MongoClient(host, port); } @Override protected String getDatabaseName() { return database; } @Bean public CustomConversions customConversions() { return new MongoCustomConversions(asList( new ZonedDateTimeToDocumentConverter(), new DocumentToZonedDateTimeConverter() )); } }
编写自定义编解码器。至少在理论上。我的 codec test branch使用 Spring Boot 2.0.5 时无法解码数据,同时使用 Spring Boot 2.0.1 工作正常。
public class ZonedDateTimeCodec implements Codec<ZonedDateTime> { public static final String DATE_TIME = "dateTime"; public static final String ZONE = "zone"; @Override public void encode(final BsonWriter writer, final ZonedDateTime value, final EncoderContext encoderContext) { writer.writeStartDocument(); writer.writeDateTime(DATE_TIME, value.toInstant().getEpochSecond() * 1_000); writer.writeString(ZONE, value.getZone().getId()); writer.writeEndDocument(); } @Override public ZonedDateTime decode(final BsonReader reader, final DecoderContext decoderContext) { reader.readStartDocument(); long epochSecond = reader.readDateTime(DATE_TIME); String zoneId = reader.readString(ZONE); reader.readEndDocument(); return ZonedDateTime.ofInstant(Instant.ofEpochSecond(epochSecond / 1_000), ZoneId.of(zoneId)); } @Override public Class<ZonedDateTime> getEncoderClass() { return ZonedDateTime.class; } } @Configuration public class MongoConfiguration extends AbstractMongoConfiguration { @Value("${spring.data.mongodb.database}") private String database; @Value("${spring.data.mongodb.host}") private String host; @Value("${spring.data.mongodb.port}") private int port; @Override public MongoClient mongoClient() { return new MongoClient(host + ":" + port, createOptions()); } private MongoClientOptions createOptions() { CodecProvider pojoCodecProvider = PojoCodecProvider.builder() .automatic(true) .build(); CodecRegistry registry = CodecRegistries.fromRegistries( createCustomCodecRegistry(), MongoClient.getDefaultCodecRegistry(), CodecRegistries.fromProviders(pojoCodecProvider) ); return MongoClientOptions.builder() .codecRegistry(registry) .build(); } private CodecRegistry createCustomCodecRegistry() { return CodecRegistries.fromCodecs( new ZonedDateTimeCodec() ); } @Override protected String getDatabaseName() { return database; } }
关于spring - 使用 Spring Boot >= 2.0.1.RELEASE 将 ZonedDateTime 保存到 MongoDB 时出现 CodecConfigurationException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52677253/