JSON Jackson

Since Camel 2.0

Jackson is a Data Format that uses the Jackson Library

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

Jackson Options

The JSON Jackson dataformat supports 21 options, which are listed below.

Name Default Java Type Description

objectMapper (common)

String

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

useDefaultObjectMapper (common)

true

Boolean

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

autoDiscoverObjectMapper (common)

false

Boolean

If set to true then Jackson will look for an objectMapper to use from the registry.

prettyPrint (common)

false

Boolean

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

useWriter (common)

false

Boolean

Force using generator that outputs JSON content using a java.io.Writer which handles character encoding. This should be preferred when using 2-byte/4-byte characters such as Japanese.

unmarshalType (common)

String

Class name of the java type to use when unmarshalling.

jsonView (advanced)

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 (advanced)

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 (advanced)

false

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 (advanced)

String

Refers to a custom collection type to lookup in the registry to use. This option should rarely be used, but allows using different collection types than java.util.Collection based as default.

useList (common)

false

Boolean

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

moduleClassNames (advanced)

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 (advanced)

String

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

enableFeatures (advanced)

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 (advanced)

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 (common)

false

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 (advanced)

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 and fastjson.

schemaResolver (advanced)

Object

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

autoDiscoverSchemaResolver (advanced)

true

Boolean

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

namingStrategy (common)

String

If set then Jackson will use the the defined Property Naming Strategy.Possible values are: LOWER_CAMEL_CASE, LOWER_DOT_CASE, LOWER_CASE, KEBAB_CASE, SNAKE_CASE and UPPER_CAMEL_CASE.

contentTypeHeader (common)

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.

Usage

2 and 4 bytes characters

Jackson will default work with UTF-8 using an optimized JSon generator that only supports UTF-8. For users that need 2-bytes or 4-bytes (such as Japanese) would need to turn on useWriter=true in the Camel dataformat, to use another JSon generator that lets java.io.Writer handle character encodings.

Using custom ObjectMapper

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

If you set up 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 gives a set of out-of-the-box converters to/from the Jackson type JSonNode, such as converting from JSonNode to String or vice versa.

Enabling more type converters and support for POJOs

To enable POJO conversion support for camel-jackson then this must be enabled, which is done by setting the following options on the CamelContext global options, as shown:

// Enable Jackson JSON type converter for more types.
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 Jackson’s own annotations in 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 add the following to your pom.xml, substituting the version number for the latest & greatest release:

<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 22 options, which are listed below.

Name Description Default Type

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

If set to true then Jackson will look for an objectMapper to use from the registry.

false

Boolean

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

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

true

Boolean

camel.dataformat.jackson.collection-type

Refers to a custom collection type to lookup in the registry to use. This option should rarely be used, but allows using different collection types than java.util.Collection based as default.

String

camel.dataformat.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.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.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.jackson.enabled

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

Boolean

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

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

String

camel.dataformat.jackson.naming-strategy

If set then Jackson will use the the defined Property Naming Strategy.Possible values are: LOWER_CAMEL_CASE, LOWER_DOT_CASE, LOWER_CASE, KEBAB_CASE, SNAKE_CASE and UPPER_CAMEL_CASE.

String

camel.dataformat.jackson.object-mapper

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

String

camel.dataformat.jackson.pretty-print

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

false

Boolean

camel.dataformat.jackson.schema-resolver

Optional schema resolver used to lookup schemas for the data in transit. The option is a org.apache.camel.component.jackson.SchemaResolver type.

String

camel.dataformat.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 and fastjson.

String

camel.dataformat.jackson.unmarshal-type

Class name of the java type to use when unmarshalling.

String

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

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

true

Boolean

camel.dataformat.jackson.use-list

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

false

Boolean

camel.dataformat.jackson.use-writer

Force using generator that outputs JSON content using a java.io.Writer which handles character encoding. This should be preferred when using 2-byte/4-byte characters such as Japanese.

false

Boolean
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