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.
}
}
我尝试保留的类如下所示：
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 +
'}';
}
}
这个答案对于OP来说可能有点晚了，但我今天遇到了同样的问题并找到了解决方案......
若要以编程方式设置它，需要在使用它之前调用MongoMappingConverter.afterPropertiesSet()。我通过阅读代码意识到了这一点 MongoTemplate.getDefaultMongoConverter(MongoDbFactory).
下面是一个示例：
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);
只是抬头。我在使用 Java 配置spring-data-mongodb 1.5.1.RELEASE时遇到了这个问题。由于某些类已更改，我正在发布我的解决方案。
在用 @Configuration 注释的配置类中添加以下定义：
@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;
}
如何使用自定义转换器自定义 mongo 在这里详细描述：
http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mapping-configuration
我注入了默认配置值，以便我可以从应用程序属性配置设置中受益。
@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);
}
}
随着java 8中java.time包的引入，我在使用新包中的新LocalDate和LocalDateTime类时遇到了类似的问题。这就是我解决它的方式：
我为所有这 4 个转换选项编写了一个转换器：
- 日期
- 到本地日期时间转换器 日期
- 到本地日期转换器
- 本地日期时间到日期转换器
- 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（请记住添加所有转换器）：
<mongo:mapping-converter>
<mongo:custom-converters>
<mongo:converter>
<bean class="package.DateToLocalDateTimeConverter" />
</mongo:converter>
</mongo:custom-converters>
</mongo:mapping-converter>
对我来说，
它将我的转换器注册为读取器而不是写入器。要解决此问题，您需要将@WritingConverter注释添加到转换器类中
@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;
}
}
自 org.springframework.data:spring-data-commons:1.13.3.RELEASE 年以来，下面介绍如何使用自定义转换器以编程方式创建MongoTemplate
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> { ... }