问题描述
我有一个带有 Java 8 日期/时间字段的简单文档
I have simple document with Java 8 date/time fields
@Document
public class Token {
private Instant createdAt;
...
}
我想坚持使用 Spring Data MongoDB 1.5 版.但是 java.time.Instant 类型的字段无法正确反序列化，因为 MappingMongoConverter 缺少 java.time 类的转换器.
that I want to persist with Spring Data MongoDB version 1.5. But fields of type java.time.Instant could not be de-serialized correctly because MappingMongoConverter lacks converters for java.time classes.
在 Spring 4 中，我发现 org.springframework.format.datetime.standard.DateTimeConverters 具有不同的 Converter，包括 InstantToLongConverter 和 LongToInstantConverter 声明为私有静态类.
In Spring 4 I found org.springframework.format.datetime.standard.DateTimeConverters with different Converters including InstantToLongConverter and LongToInstantConverter declared as private static classes.
如何配置 MongoTemplate 以使用它们将 Instant 字段映射到 long?
How can I configure MongoTemplate to use them to map Instant fields to longs?
推荐答案
我不知道这是否是最好的方法，但我在 Spring Data MongoDB 中添加了 Java 8 Date/Time (JSR-310) 类型支持 1.5.0.RELEASE 像这样:
I don't know if this is the best way but I added Java 8 Date/Time (JSR-310) types support to Spring Data MongoDB 1.5.0.RELEASE like this:
第一步.添加简单的 Spring
Converters
public class InstantToLongConverter implements Converter<Instant, Long> {
@Override
public Long convert(Instant instant) {
return instant.toEpochMilli();
}
}
public class LongToInstantConverter implements Converter<Long, Instant> {
@Override
public Instant convert(Long source) {
return Instant.ofEpochMilli(source);
}
}
public class LocalDateToStringConverter implements Converter<LocalDate, String> {
@Override
public String convert(LocalDate localDate) {
return localDate.toString();
}
}
public class StringToLocalDateConverter implements Converter<String, LocalDate> {
@Override
public LocalDate convert(String source) {
return LocalDate.parse(source);
}
}
第二步.在 AbstractMongoConfiguration 实现中使用 MappingMongoConverter 注册这些自定义 Converter，如下所示:
Second step. Register these custom Converters with MappingMongoConverter in your AbstractMongoConfiguration implementation like this:
@Configuration
@EnableMongoRepositories(basePackages = {"my.app.repository"})
public class MongoConfiguration extends AbstractMongoConfiguration {
...
@Override
public CustomConversions customConversions() {
return new CustomConversions(Arrays.asList(
new InstantToLongConverter(), new LongToInstantConverter(),
new LocalDateToStringConverter(), new StringToLocalDateConverter()));
}
}
现在您的文档的 Instant 字段将作为长值和 LocalDates 作为字符串持久化.
Now your document's Instant fields will be persisted as long values and LocalDates as Strings.
这篇关于Java 8 日期/时间 (JSR-310) 类型与 Spring Data MongoDB 的映射的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！