beadledom-jackson¶

This project provides an ObjectMapper with some default configuration via the Guice JacksonModule. This module also provides hooks into a Guice multibinder for the Jackson Module. This multibinder provides the ability to extend the capabilities of the injected ObjectMapper by registering all bound Jackson modules to the injected ObjectMapper.

Download¶

Download using Maven¶

<dependency>
    <groupId>com.cerner.beadledom</groupId>
    <artifactId>beadledom-jackson</artifactId>
    <version>[insert latest version]</version>
</dependency>

Usage¶

To add your own Jackson modules to the injected ObjectMapper simply bind them to the module multibinder:

public class MyModule extends AbstractModule {
  @Override
  public void configure() {
    install(new JacksonModule());

    Multibinder<Module> jacksonModules = Multibinder.newSetBinder(binder(), Module.class);
    jacksonModules.addBinding().to(MyJacksonModule.class);
  }
}

Or with Guice 4:

public class MyModule extends AbstractModule {
  @Override
  public void configure() {
    install(new JacksonModule());
  }

  @ProvidesIntoSet
  Module provideMyJacksonModule() {
    return new MyJacksonModule();
  }
}

Jackson ObjectMapper Features¶

Defaults¶

The following Jackson features are set by default

Camel case is converted to snake case
Null values are not included
Unknown fields do not cause the deserialization to fail
Dates are not serialized as Timestamps
Dates are serialized as Strings

Enabling/Disabling Jackson ObjectMapper features via Guice¶

ObjectMapper features can be enabled or disabled by adding the features to their respective Guice multibinders exposed by the JacksonModule. To configure the injected ObjectMapper, the following classes can be used:

SerializationFeatureFlag to configure ObjectMapper’s features defined in the SerializationFeature class
DeserializationFeatureFlag to configure ObjectMapper’s defined in the DeserializationFeature class
MapperFeatureFlag to configure ObjectMapper’s features defined in the MapperFeature class
JsonParserFeatureFlag to configure ObjectMapper’s defined in the JsonParser.Feature class
JsonGeneratorFeatureFlag to configure ObjectMapper’s defined in the JsonGenerator.Feature class

In your Jackson guice module add your feature object to the multibinder:

@ProvidesIntoSet
SerializationFeatureFlag getSerializationFeature() {
  return SerializationFeatureFlag.create(SerializationFeature.FEATURE1, true);
}

@ProvidesIntoSet
SerializationFeatureFlag getSerializationFeature() {
  return SerializationFeatureFlag.create(SerializationFeature.FEATURE2, true);
}

@ProvidesIntoSet
DeserializationFeatureFlag getDeserializationFeature() {
  return DeserializationFeatureFlag.create(DeserializationFeature.FEATURE_NAME, true);
}

@ProvidesIntoSet
JsonGeneratorFeatureFlag getJsonGeneratorFeature() {
  return JsonGeneratorFeatureFlag.create(JsonGenerator.Feature.FEATURE_NAME, true);
}

@ProvidesIntoSet
JsonParserFeatureFlag getJsonParserFeature() {
  return JsonParserFeatureFlag.create(JsonParser.Feature.FEATURE_NAME, true);
}

@ProvidesIntoSet
MapperFeatureFlag getMapperFeature() {
  return MapperFeatureFlag.create(MapperFeature.FEATURE_NAME, true);
}

FieldFilter¶

The FieldFilter class provides a way to filter JSON to only a set of specified fields. See the javadoc for FieldFilter for usage.