在泽西岛的Jackson和一个实体的多个序列化器

I'm implementing a REST backend with Jersey 2.11 and Jackson 2.4.0 for serialization. My entity looks like this:

我正在使用Jersey 2.11和Jackson 2.4.0实现一个REST后端。我的实体是这样的:

public class Measurement {

public Measurement() {
    super();
}

private Long id;
private Double lat;
private Double lon;
private Long timestamp;
private User owner;
}

In some responses I'd like this entity serialized as GeoJSON and in others as Measurement with the User.id instead of the User object. Therefore I wrote two custom JsonSerializers and registered them in my ObjectMapperResolver class.

在一些响应中，我希望将这个实体序列化为GeoJSON，在另一些响应中作为与用户的度量。id而不是User对象。因此，我编写了两个自定义JsonSerializers，并将它们注册到ObjectMapperResolver类中。

@Provider
public class ObjectMapperResolver implements ContextResolver<ObjectMapper> {

private final ObjectMapper defaultMapper;
private final ObjectMapper geojsonMapper;

public ObjectMapperResolver() {
    defaultMapper = createDefaultMapper();
    geojsonMapper = createGeojsonMapper();
}

private static ObjectMapper createDefaultMapper() {
    SimpleModule module = new SimpleModule();
    module.addSerializer(Measurement.class, new MeasurementSerializer());

    return new ObjectMapper()
    .enable(SerializationFeature.INDENT_OUTPUT)
    .registerModule(module);
}

private static ObjectMapper createGeojsonMapper() {
    SimpleModule module = new SimpleModule();
    module.addSerializer(Measurement.class, new GeoJSONSerializer());

    return new ObjectMapper()
    .enable(SerializationFeature.INDENT_OUTPUT)
    .registerModule(module);
}

@Override
public ObjectMapper getContext(Class<?> type) {
    if (type.equals(Measurement.class)) {
        return geojsonMapper;
    }
    else {
        return defaultMapper;
    }
}

}

In the current setup whenever a Measurement is serialized its serialized as GeoJSON. Whenever my other entities (which do contain Measurements) are serialized the defaultMapper is used. I'd need a possibility to switch Serializer/Mapper for one single entity class (Measurement.class)

在当前设置中，当度量被序列化为GeoJSON时。当我的其他实体(确实包含度量)被序列化时，使用defaultMapper。我需要为单个实体类(measure .class)切换序列化器/映射器的可能性

Best regards!

最好的问候!

1 个解决方案

#1

Here is what I did in my spring application: 1. Created my CustomObjectMapper classes. 2. Created class specific json generator methods. 3. Autowired required object mapper in the controller.

以下是我在spring应用程序中所做的:1。创建我的CustomObjectMapper类。2。创建类特定的json生成器方法。3所示。在控制器中自动连接所需的对象映射器。

Mapper1:

public class CustomObjectMapper1 extends ObjectMapper {
    public CustomObjectMapper1() {
        super();
        super.setSerializationInclusion(JsonInclude.Include.ALWAYS);
        super.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
        super.setDateFormat(df);
    }
    public byte[] generateJson(Object value) throws IOException, JsonGenerationException, JsonMappingException {
        Hibernate4Module hm = new Hibernate4Module();
        hm.configure(Hibernate4Module.Feature.USE_TRANSIENT_ANNOTATION, false);
        hm.configure(Hibernate4Module.Feature.FORCE_LAZY_LOADING, false);
        return super.registerModule(hm).writeValueAsBytes(value);
    }
}

Mapper2:

public class CustomObjectMapper2 extends ObjectMapper {
    public CustomObjectMapper2() {
        super();
        super.setDateFormat(df);
    }
    public byte[] generateJson(Object value) throws IOException, JsonGenerationException, JsonMappingException {
        Hibernate4Module hm = new Hibernate4Module();
        return super.registerModule(hm).writeValueAsBytes(value);
    }
}

In controller:

控制器:

...
byte[] json = customObjectMapper1.generateJson(myObject);
return json;

...
byte[] json = customObjectMapper2.generateJson(myObject);
return json;

Hope it helps.

希望它可以帮助。

#1