JSON Jackson

Since Camel 2.0

Jackson is a Data Format which uses the Jackson Library

from("activemq:My.Queue").
  marshal().json(JsonLibrary.Jackson).
  to("mqseries:Another.Queue");

Jackson Options

The JSON Jackson dataformat supports 19 options, which are listed below.

Name Default Java Type Description

objectMapper

String

Lookup and use the existing ObjectMapper with the given id when using Jackson.

useDefaultObjectMapper

true

Boolean

Whether to lookup and use default Jackson ObjectMapper from the registry.

prettyPrint

Boolean

To enable pretty printing output nicely formatted. Is by default false.

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. This option will have no effect on the others Json DataFormat, like gson, fastjson and xstream.

autoDiscoverObjectMapper

Boolean

If set to true then Jackson will lookup for an objectMapper into the registry.

contentTypeHeader

true

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.

schemaResolver

String

Optional schema resolver used to lookup schemas for the data in transit.

autoDiscoverSchemaResolver

true

Boolean

When not disabled, the SchemaResolver will be looked up into the registry.

Using custom ObjectMapper

You can configure JacksonDataFormat to use a custom ObjectMapper in case you need more control of the mapping configuration.

If you setup a single ObjectMapper in the registry, then Camel will automatic lookup and use this ObjectMapper. For example if you use Spring Boot, then Spring Boot can provide a default ObjectMapper for you if you have Spring MVC enabled. And this would allow Camel to detect that there is one bean of ObjectMapper class type in the Spring Boot bean registry and then use it. When this happens you should set a INFO logging from Camel.

Using Jackson for automatic type conversion

The camel-jackson module allows integrating Jackson as a Type Converter. This works in similar ways that JAXB integrates with Camels type converter.

To use this camel-jackson must be enabled, which is done by setting the following options on the CamelContext global options, as shown:

// Enable Jackson JSON type converter.
camelContext.getGlobalOptions().put("CamelJacksonEnableTypeConverter", "true");
// Allow Jackson JSON to convert to pojo types also
// (by default Jackson only converts to String and other simple types)
getContext().getGlobalOptions().put("CamelJacksonTypeConverterToPojo", "true");

The camel-jackson type converter integrates with JAXB which means you can annotate POJO class with JAXB annotations that Jackson can use. You can also use Jacksons own annotations on your POJO classes.

Dependencies

To use Jackson in your camel routes you need to add the dependency on camel-jackson 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</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

Spring Boot Auto-Configuration

When using 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-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 20 options, which are listed below.

Name Description Default Type

camel.dataformat.json-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.json-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.json-jackson.auto-discover-object-mapper

If set to true then Jackson will lookup for an objectMapper into the registry

false

Boolean

camel.dataformat.json-jackson.auto-discover-schema-resolver

When not disabled, the SchemaResolver will be looked up into the registry

true

Boolean

camel.dataformat.json-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.json-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.json-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.json-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.json-jackson.enabled

Whether to enable auto configuration of the json-jackson data format. This is enabled by default.

Boolean

camel.dataformat.json-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.json-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.json-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.json-jackson.module-refs

To use custom Jackson modules referred from the Camel registry. Multiple modules can be separated by comma.

String

camel.dataformat.json-jackson.object-mapper

Lookup and use the existing ObjectMapper with the given id when using Jackson.

String

camel.dataformat.json-jackson.pretty-print

To enable pretty printing output nicely formatted. Is by default false.

false

Boolean

camel.dataformat.json-jackson.schema-resolver

Optional schema resolver used to lookup schemas for the data in transit.

String

camel.dataformat.json-jackson.timezone

If set then Jackson will use the Timezone when marshalling/unmarshalling. This option will have no effect on the others Json DataFormat, like gson, fastjson and xstream.

String

camel.dataformat.json-jackson.unmarshal-type

Class name of the java type to use when unmarshalling

String

camel.dataformat.json-jackson.use-default-object-mapper

Whether to lookup and use default Jackson ObjectMapper from the registry.

true

Boolean

camel.dataformat.json-jackson.use-list

To unmarshal to a List of Map or a List of Pojo.

false

Boolean