JSon XStream DataFormat

Since Camel 2.0

XStream is a Data Format which uses the XStream library to marshal and unmarshal Java objects to and from JSon. However XStream was created primary for working with XML and therefore using JSon with XStream is not as popular as for example Jackson is for JSon.

To use XStream in your camel routes you need to add the a dependency on camel-xstream which implements this data format.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-xstream</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

Options

The JSon XStream dataformat supports 20 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

false

Boolean

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

library

Jackson

JsonLibrary

Which json library to use.

unmarshalTypeName

String

Class name of the java type to use when unarmshalling

jsonView

Class

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

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.

collectionTypeName

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

false

Boolean

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

enableJaxbAnnotationModule

false

Boolean

Whether to enable the JAXB annotations module when using jackson. When enabled then JAXB annotations can be used by Jackson.

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

permissions

String

Adds permissions that controls which Java packages and classes XStream is allowed to use during unmarshal from xml/json to Java beans. A permission must be configured either here or globally using a JVM system property. The permission can be specified in a syntax where a plus sign is allow, and minus sign is deny. Wildcards is supported by using . as prefix. For example to allow com.foo and all subpackages then specfy com.foo.. Multiple permissions can be configured separated by comma, such as com.foo.,-com.foo.bar.MySecretBean. The following default permission is always included: -,java.lang.,java.util. unless its overridden by specifying a JVM system property with they key org.apache.camel.xstream.permissions.

allowUnmarshallType

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

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

false

Boolean

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

contentTypeHeader

false

Boolean

Whether the data format should set the Content-Type header with the type from the data format if the data format is capable of doing so. For example application/xml for data formats marshalling to XML, or application/json for data formats marshalling to JSon etc.

Using the Java DSL

// lets turn Object messages into XML then send to MQSeries
from("activemq:My.Queue").
  marshal().json(JsonLibrary.XStream).
  to("mqseries:Another.Queue");

If you would like to configure the XStream instance used by the Camel for the message transformation, you can simply pass a reference to that instance on the DSL level.

XStream xStream = new XStream();
xStream.aliasField("money", PurchaseOrder.class, "cash");
// new Added setModel option since Camel 2.14
xStream.setModel("NO_REFERENCES");
...

from("direct:marshal").
  marshal(new XStreamDataFormat(xStream)).
  to("mock:marshaled");