Chapter 81. Protobuf Jackson
Chapter 81. Protobuf Jackson Jackson Protobuf is a Data Format which uses the Jackson library with the Protobuf extension to unmarshal a Protobuf payload into Java objects or to marshal Java objects into a Protobuf payload. Note If you are familiar with Jackson, this Protobuf data format behaves in the same way as its JSON counterpart, and thus can be used with classes annotated for JSON serialization/deserialization. from("kafka:topic"). unmarshal().protobuf(ProtobufLibrary.Jackson, JsonNode.class). to("log:info"); 81.1. Configuring the SchemaResolver Since Protobuf serialization is schema-based, this data format requires that you provide a SchemaResolver object that is able to lookup the schema for each exchange that is going to be marshalled/unmarshalled. You can add a single SchemaResolver to the registry and it will be looked up automatically. Or you can explicitly specify the reference to a custom SchemaResolver. 81.2. Protobuf Jackson Options The Protobuf Jackson dataformat supports 18 options, which are listed below. Name Default Java Type Description contentTypeHeader Boolean Whether the data format should set the Content-Type header with the type from the data format. For example application/xml for data formats marshalling to XML, or application/json for data formats marshalling to JSON. objectMapper String Lookup and use the existing ObjectMapper with the given id when using Jackson. useDefaultObjectMapper Boolean Whether to lookup and use default Jackson ObjectMapper from the registry. unmarshalType String Class name of the java type to use when unmarshalling. jsonView String When marshalling a POJO to JSON you might want to exclude certain fields from the JSON output. With Jackson you can use JSON views to accomplish this. This option is to refer to the class which has JsonView annotations. include String If you want to marshal a pojo to JSON, and the pojo has some fields with null values. And you want to skip these null values, you can set this option to NON_NULL. allowJmsType Boolean Used for JMS users to allow the JMSType header from the JMS spec to specify a FQN classname to use to unmarshal to. collectionType String Refers to a custom collection type to lookup in the registry to use. This option should rarely be used, but allows to use different collection types than java.util.Collection based as default. useList Boolean To unmarshal to a List of Map or a List of Pojo. moduleClassNames String To use custom Jackson modules com.fasterxml.jackson.databind.Module specified as a String with FQN class names. Multiple classes can be separated by comma. moduleRefs String To use custom Jackson modules referred from the Camel registry. Multiple modules can be separated by comma. enableFeatures String Set of features to enable on the Jackson com.fasterxml.jackson.databind.ObjectMapper. The features should be a name that matches a enum from com.fasterxml.jackson.databind.SerializationFeature, com.fasterxml.jackson.databind.DeserializationFeature, or com.fasterxml.jackson.databind.MapperFeature Multiple features can be separated by comma. disableFeatures String Set of features to disable on the Jackson com.fasterxml.jackson.databind.ObjectMapper. The features should be a name that matches a enum from com.fasterxml.jackson.databind.SerializationFeature, com.fasterxml.jackson.databind.DeserializationFeature, or com.fasterxml.jackson.databind.MapperFeature Multiple features can be separated by comma. allowUnmarshallType Boolean If enabled then Jackson is allowed to attempt to use the CamelJacksonUnmarshalType header during the unmarshalling. This should only be enabled when desired to be used. timezone String If set then Jackson will use the Timezone when marshalling/unmarshalling. autoDiscoverObjectMapper Boolean If set to true then Jackson will lookup for an objectMapper into the registry. schemaResolver String Optional schema resolver used to lookup schemas for the data in transit. autoDiscoverSchemaResolver Boolean When not disabled, the SchemaResolver will be looked up into the registry. 81.3. Using custom ProtobufMapper You can configure JacksonProtobufDataFormat to use a custom ProtobufMapper in case you need more control of the mapping configuration. If you setup a single ProtobufMapper in the registry, then Camel will automatic lookup and use this ProtobufMapper . 81.4. Dependencies To use Protobuf Jackson in your camel routes you need to add the dependency on camel-jackson-protobuf which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jackson-protobuf</artifactId> <version>{CamelSBVersion}</version> <!-- use the same version as your Camel core version --> </dependency> 81.5. Spring Boot Auto-Configuration When using protobuf-jackson with Spring Boot make sure to use the following Maven dependency to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-jackson-protobuf-starter</artifactId> </dependency> The component supports 19 options, which are listed below. Name Description Default Type camel.dataformat.protobuf-jackson.allow-jms-type Used for JMS users to allow the JMSType header from the JMS spec to specify a FQN classname to use to unmarshal to. false Boolean camel.dataformat.protobuf-jackson.allow-unmarshall-type If enabled then Jackson is allowed to attempt to use the CamelJacksonUnmarshalType header during the unmarshalling. This should only be enabled when desired to be used. false Boolean camel.dataformat.protobuf-jackson.auto-discover-object-mapper If set to true then Jackson will lookup for an objectMapper into the registry. false Boolean camel.dataformat.protobuf-jackson.auto-discover-schema-resolver When not disabled, the SchemaResolver will be looked up into the registry. true Boolean camel.dataformat.protobuf-jackson.collection-type Refers to a custom collection type to lookup in the registry to use. This option should rarely be used, but allows to use different collection types than java.util.Collection based as default. String camel.dataformat.protobuf-jackson.content-type-header Whether the data format should set the Content-Type header with the type from the data format. For example application/xml for data formats marshalling to XML, or application/json for data formats marshalling to JSON. true Boolean camel.dataformat.protobuf-jackson.disable-features Set of features to disable on the Jackson com.fasterxml.jackson.databind.ObjectMapper. The features should be a name that matches a enum from com.fasterxml.jackson.databind.SerializationFeature, com.fasterxml.jackson.databind.DeserializationFeature, or com.fasterxml.jackson.databind.MapperFeature Multiple features can be separated by comma. String camel.dataformat.protobuf-jackson.enable-features Set of features to enable on the Jackson com.fasterxml.jackson.databind.ObjectMapper. The features should be a name that matches a enum from com.fasterxml.jackson.databind.SerializationFeature, com.fasterxml.jackson.databind.DeserializationFeature, or com.fasterxml.jackson.databind.MapperFeature Multiple features can be separated by comma. String camel.dataformat.protobuf-jackson.enabled Whether to enable auto configuration of the protobuf-jackson data format. This is enabled by default. Boolean camel.dataformat.protobuf-jackson.include If you want to marshal a pojo to JSON, and the pojo has some fields with null values. And you want to skip these null values, you can set this option to NON_NULL. String camel.dataformat.protobuf-jackson.json-view When marshalling a POJO to JSON you might want to exclude certain fields from the JSON output. With Jackson you can use JSON views to accomplish this. This option is to refer to the class which has JsonView annotations. String camel.dataformat.protobuf-jackson.module-class-names To use custom Jackson modules com.fasterxml.jackson.databind.Module specified as a String with FQN class names. Multiple classes can be separated by comma. String camel.dataformat.protobuf-jackson.module-refs To use custom Jackson modules referred from the Camel registry. Multiple modules can be separated by comma. String camel.dataformat.protobuf-jackson.object-mapper Lookup and use the existing ObjectMapper with the given id when using Jackson. String camel.dataformat.protobuf-jackson.schema-resolver Optional schema resolver used to lookup schemas for the data in transit. String camel.dataformat.protobuf-jackson.timezone If set then Jackson will use the Timezone when marshalling/unmarshalling. String camel.dataformat.protobuf-jackson.unmarshal-type Class name of the java type to use when unmarshalling. String camel.dataformat.protobuf-jackson.use-default-object-mapper Whether to lookup and use default Jackson ObjectMapper from the registry. true Boolean camel.dataformat.protobuf-jackson.use-list To unmarshal to a List of Map or a List of Pojo. false Boolean
from("kafka:topic"). unmarshal().protobuf(ProtobufLibrary.Jackson, JsonNode.class). to("log:info"); <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jackson-protobuf</artifactId> <version>{CamelSBVersion}</version> <!-- use the same version as your Camel core version --> </dependency> <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-jackson-protobuf-starter</artifactId> </dependency>