spring - 使用 Spring Boot >= 2.0.1.RELEASE 将 ZonedDateTime 保存到 MongoDB 时出现 CodecConfigurationException

Question

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。

Answer 1

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:

1. 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。)

2. 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()
           ));
       }
   }
   

3. 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;
       }
   }