java - 以编程方式设置 MongoDb 转换器

Question

我正在尝试使用带有 spring-data-mongodb 的自定义转换器。我想以编程方式创建它，但出现以下错误：

org.springframework.core.convert.ConverterNotFoundException: No converter found capable of     converting from type org.joda.time.LocalDate to type java.lang.String
at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:475)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:175)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:154)
....
....

以下是失败的代码片段：

    Mongo mongo = new Mongo();
    MongoDbFactory mongoDbFactory = new SimpleMongoDbFactory(mongo, "database");

    List<Converter> converters = new ArrayList<>();
    converters.add(new LocalDateWriteConverter());
    converters.add(new LocalDateReadConverter());
    CustomConversions customConversions = new CustomConversions(converters);

    MappingContext mappingContext = new SimpleMongoMappingContext();
    MappingMongoConverter mappingMongoConverter = new MappingMongoConverter(mongoDbFactory, mappingContext);
    mappingMongoConverter.setCustomConversions(customConversions);

    MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory, mappingMongoConverter);

    MongoDbEvent mongoEvent = new MongoDbEvent(new LocalDate(2012, 12, 8));
    mongoTemplate.insert(mongoEvent);

这是我的转换器类：

class LocalDateReadConverter implements Converter<String, LocalDate> {
    @Override
    public LocalDate convert(String s) {
        // Conversion code omitted.
    }
}

class LocalDateWriteConverter implements Converter<LocalDate, String> {

    @Override
    public String convert(LocalDate localDate) {
        // Conversion code omitted.
    }
}

我试图坚持的课程如下所示：

import org.joda.time.LocalDate;

public class MongoDbEvent {

    private String id;
    private LocalDate date;

    public MongoDbEvent(LocalDate date) {
        this.date = date;
    }

    public String getId() {
        return id;
    }

    public LocalDate getDate() {
        return date;
    }

    @Override
    public String toString() {
        return "MongoDbEvent{" +
                "id='" + id + '\'' +
                ", date=" + date +
                '}';
        }
}

score 30 · Accepted Answer

对于OP来说，这个答案可能有点晚了，但我今天遇到了同样的问题并找到了解决方案......

要以编程方式设置它，您需要MongoMappingConverter.afterPropertiesSet()在使用它之前调用它。我通过阅读MongoTemplate.getDefaultMongoConverter(MongoDbFactory).

这是一个例子：

MappingMongoConverter converter = new MappingMongoConverter(mongoDbFactory, context);
converter.setTypeMapper(mapper);
converter.setCustomConversions(new CustomConversions(
        Arrays.asList(
                new TimeZoneReadConverter(),
                new TimeZoneWriteConverter()
        )
));
converter.afterPropertiesSet();
MongoTemplate template = new MongoTemplate(mongoDbFactory, converter);

score 21 · Accepted Answer

只是一个抬头。我在spring-data-mongodb 1.5.1.RELEASE使用 Java Configuration 时遇到了这个问题。由于某些课程发生了变化，我正在发布我的解决方案。

在带有注释的配置类中添加以下定义@Configuration：

@Bean
public Mongo mongo() throws Exception {
    MongoPropertiesResolver resolver = mongoResolver();
    return new MongoClient(resolver.getUrl());
}

@Bean
public MongoDbFactory mongoDbFactory() throws Exception {
    return new SimpleMongoDbFactory(mongo(), "database");
}

@Bean
public MongoTemplate mongoTemplate() throws Exception {
    return new MongoTemplate(mongoDbFactory(), mongoConverter());
}

@Bean
public CustomConversions customConversions() {
    List<Converter<?, ?>> converters = new ArrayList<Converter<?, ?>>();
    converters.add(new TimeZoneReadConverter());
    converters.add(new TimeZoneReadConverter());
    return new CustomConversions(converters);
}

@Bean
public MappingMongoConverter mongoConverter() throws Exception {
    MongoMappingContext mappingContext = new MongoMappingContext();
    DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory());
    MappingMongoConverter mongoConverter = new MappingMongoConverter(dbRefResolver, mappingContext);
    mongoConverter.setCustomConversions(customConversions());
    return mongoConverter;
}

score 7 · Accepted Answer

这里详细描述了如何使用自定义转换器自定义 mongo：

http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mapping-configuration

我注入了默认配置值，因此我可以从 application.properties 配置设置中受益。

  @Configuration
  public class MongoConfiguration extends AbstractMongoConfiguration {
    @Value("${spring.data.mongodb.database:test}")
    String database;

    @Value("${spring.data.mongodb.host:localhost}:${spring.data.mongodb.port:27017}")
    String host;

    @Override
    protected String getDatabaseName() {
      return database;
    }

    @Override
    public Mongo mongo() throws Exception {
      return new MongoClient(host);
    }

    @Bean
    @Override
    public CustomConversions customConversions() {
      List<Converter<?, ?>> converterList = new ArrayList<Converter<?, ?>>();
      converterList.add(new MongoColorWriter());
      converterList.add(new MongoColorReader());
      return new CustomConversions(converterList);
    }
  }

score 2 · Accepted Answer

随着 java.time 包在 java 8 中的引入，我在新包中使用新的 LocalDate 和 LocalDateTime 类时遇到了类似的问题。这就是我解决它的方法：

我为所有 4 个转换选项编写了一个转换器：

DateToLocalDateTime 转换器
日期到本地日期转换器
LocalDateTimeToDateConverter
LocalDateToDateConverter

这是一个例子

public class DateToLocalDateTimeConverter implements Converter<Date, LocalDateTime> {

    @Override 
    public LocalDateTime convert(Date source) { 
        return source == null ? null : LocalDateTime.ofInstant(source.toInstant(), ZoneId.systemDefault()); 
    }
}

然后通过将其包含在 mongodb 连接的 xml 配置中，我能够使用 mongodb 在 java 8 日期中工作（记得添加所有转换器）：

<mongo:mapping-converter>
    <mongo:custom-converters>
        <mongo:converter>
            <bean class="package.DateToLocalDateTimeConverter" />
        </mongo:converter>
    </mongo:custom-converters>
</mongo:mapping-converter>

score 1 · Accepted Answer

对我来说，它是将我的转换器注册为读者而不是作家。要解决此问题，您需要将 @WritingConverter 注释添加到转换器类

@Component
@WritingConverter
public class NoteWriterConverter implements Converter<Note, DBObject> {

@Override
public DBObject convert(Note source) {
    DBObject obj = new BasicDBObject();

    obj.put("title", source.getTitle());
    obj.put("reviewDate", source.getReviewDate());

    obj.removeField("_class");
    return obj;
    }
}

score 1 · Accepted Answer

既然org.springframework.data:spring-data-commons:1.13.3.RELEASE，这里是如何以编程方式创建一个MongoTemplate自定义转换器

public MongoTemplate mongoTemplate(String mongoUri) throws Exception {
    MongoDbFactory factory = new SimpleMongoDbFactory(new MongoClientURI(mongoUri));
    CustomConversions conversions = new CustomConversions(
            Arrays.asList(new FooWriteConverter(), new FooReadConverter()));
    MongoMappingContext mappingContext = new MongoMappingContext();
    DbRefResolver dbRefResolver = new DefaultDbRefResolver(factory);
    MappingMongoConverter mongoConverter = new MappingMongoConverter(dbRefResolver, mappingContext);
    mongoConverter.setCustomConversions(conversions);
    mongoConverter.afterPropertiesSet();
    return new MongoTemplate(factory, mongoConverter);
}

转换器（省略实现）

class FooWriteConverter implements Converter<Foo, DBObject> { ... }
class FooReadConverter implements Converter<DBObject, Foo> { ... }

java - 以编程方式设置 MongoDb 转换器

6 回答 6

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