Spring Boot双MongoDB实例ZonedDateTime转换器配置失败

问题场景 #

• Spring Boot 2.7.6配置主从两个MongoDB实例，集合包含ZonedDateTime类型字段
• 单库连接时，自定义MongoCustomConversions转换器可正常处理该类型
• 双库配置后，保存数据抛出异常：

  org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class java.time.ZonedDateTime.

• 尝试共用转换器配置，问题依旧
• 项目Maven指定Java 1.8，运行在OpenJDK19的Docker容器中

当前配置代码 #

主库配置 #

@Bean
@Primary
@Override
public MongoCustomConversions customConversions() {
    List<Converter<?, ?>> converters = new ArrayList<>();
    converters.add(new MultipleMongoConfig.DateToZonedDateTimeConverter());
    converters.add(new MultipleMongoConfig.ZonedDateTimeToDateConverter());
    return new MongoCustomConversions(converters);
}

@Bean
@Primary
public MongoDatabaseFactory primaryFactory() throws Exception {
    return new SimpleMongoClientDatabaseFactory(((connection)));
}

@Primary
@Bean(name = "primaryMongoTemplate")
public MongoTemplate primaryMongoTemplate() throws Exception {     
    return new MongoTemplate(primaryFactory());
}

从库配置 #

@Bean(name = "secondaryMongoTemplate")
public MongoTemplate secondaryMongoTemplate() throws Exception {
    return new MongoTemplate(secondaryFactory());
}

@Bean    
@Override
public MongoCustomConversions customConversions() {
    List<Converter<?, ?>> converters = new ArrayList<>();
    converters.add(new MultipleMongoConfig.DateToZonedDateTimeConverter());
    converters.add(new MultipleMongoConfig.ZonedDateTimeToDateConverter());
    return new MongoCustomConversions(converters);
}

@Bean
public MongoDatabaseFactory secondaryFactory() throws Exception {
    return new SimpleMongoClientDatabaseFactory(((connection)));
}

YAML配置 #

main:
    allow-bean-definition-overriding: true

问题原因 #

1. 双库配置时，直接通过MongoTemplate(MongoDatabaseFactory)构造实例，未将自定义的MongoCustomConversions绑定到对应的MappingMongoConverter中，导致MongoTemplate使用默认转换器，无法处理ZonedDateTime类型。
2. 编译JDK版本（1.8）与运行JDK版本（19）不一致，可能引发Java时间类兼容性问题，加重序列化异常。

解决方案 #

1. 手动绑定自定义转换器到每个MongoTemplate #

修改主库和从库的配置，通过MappingMongoConverter将自定义转换器关联到对应的MongoTemplate：

主库配置修改

@Bean
@Primary
public MongoCustomConversions primaryCustomConversions() {
    List<Converter<?, ?>> converters = new ArrayList<>();
    converters.add(new MultipleMongoConfig.DateToZonedDateTimeConverter());
    converters.add(new MultipleMongoConfig.ZonedDateTimeToDateConverter());
    return new MongoCustomConversions(converters);
}

@Bean
@Primary
public MappingMongoConverter primaryMappingMongoConverter(MongoDatabaseFactory primaryFactory, MongoCustomConversions primaryCustomConversions) throws Exception {
    MappingMongoConverter converter = new MappingMongoConverter(new DefaultDbRefResolver(primaryFactory), new MongoMappingContext());
    converter.setCustomConversions(primaryCustomConversions);
    converter.afterPropertiesSet();
    return converter;
}

@Primary
@Bean(name = "primaryMongoTemplate")
public MongoTemplate primaryMongoTemplate(MongoDatabaseFactory primaryFactory, MappingMongoConverter primaryMappingMongoConverter) throws Exception {
    return new MongoTemplate(primaryFactory, primaryMappingMongoConverter);
}

@Bean
@Primary
public MongoDatabaseFactory primaryFactory() throws Exception {
    return new SimpleMongoClientDatabaseFactory(((connection)));
}

从库配置修改

@Bean(name = "secondaryCustomConversions")
public MongoCustomConversions secondaryCustomConversions() {
    List<Converter<?, ?>> converters = new ArrayList<>();
    converters.add(new MultipleMongoConfig.DateToZonedDateTimeConverter());
    converters.add(new MultipleMongoConfig.ZonedDateTimeToDateConverter());
    return new MongoCustomConversions(converters);
}

@Bean(name = "secondaryMappingMongoConverter")
public MappingMongoConverter secondaryMappingMongoConverter(MongoDatabaseFactory secondaryFactory, @Qualifier("secondaryCustomConversions") MongoCustomConversions secondaryCustomConversions) throws Exception {
    MappingMongoConverter converter = new MappingMongoConverter(new DefaultDbRefResolver(secondaryFactory), new MongoMappingContext());
    converter.setCustomConversions(secondaryCustomConversions);
    converter.afterPropertiesSet();
    return converter;
}

@Bean(name = "secondaryMongoTemplate")
public MongoTemplate secondaryMongoTemplate(MongoDatabaseFactory secondaryFactory, @Qualifier("secondaryMappingMongoConverter") MappingMongoConverter secondaryMappingMongoConverter) throws Exception {
    return new MongoTemplate(secondaryFactory, secondaryMappingMongoConverter);
}

@Bean
public MongoDatabaseFactory secondaryFactory() throws Exception {
    return new SimpleMongoClientDatabaseFactory(((connection)));
}

2. 统一Java版本（推荐） #

将编译和运行的Java版本统一，避免兼容性问题：

• 若保留JDK8运行环境，修改Docker容器使用OpenJDK8镜像
• 若升级到JDK19，修改pom.xml的编译版本：

<properties>
    <maven.compiler.source>19</maven.compiler.source>
    <maven.compiler.target>19</maven.compiler.target>
</properties>

3. 移除Bean覆盖配置 #

由于已经通过指定Bean名称（如primaryCustomConversions、secondaryCustomConversions）避免冲突，可以删除YAML中的main.allow-bean-definition-overriding: true，防止意外覆盖Bean定义。

验证 #

启动项目后，尝试保存包含ZonedDateTime字段的文档，检查是否正常完成序列化与反序列化，无CodecConfigurationException异常抛出。

内容的提问来源于stack exchange，提问作者Armen Arzumanyan