JSON XStream

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 3 options, which are listed below.

Name Default Java Type Description

Name	Default	Java Type	Description
prettyPrint	`false`	`Boolean`	To enable pretty printing output nicely formatted. Is by default false.
dropRootNode	`false`	`Boolean`	Whether XStream will drop the root node in the generated JSon. You may want to enable this when using POJOs; as then the written object will include the class name as root node, which is often not intended to be written in the JSON output.
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

prettyPrint

false

Boolean

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

dropRootNode

false

Boolean

Whether XStream will drop the root node in the generated JSon. You may want to enable this when using POJOs; as then the written object will include the class name as root node, which is often not intended to be written in the JSON output.

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

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");

Spring Boot Auto-Configuration

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

The component supports 13 options, which are listed below.

Name	Description	Default	Type
camel.dataformat.json-xstream.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-xstream.drop-root-node	Whether XStream will drop the root node in the generated JSon. You may want to enable this when using POJOs; as then the written object will include the class name as root node, which is often not intended to be written in the JSON output.	false	Boolean
camel.dataformat.json-xstream.enabled	Whether to enable auto configuration of the json-xstream data format. This is enabled by default.		Boolean
camel.dataformat.json-xstream.pretty-print	To enable pretty printing output nicely formatted. Is by default false.	false	Boolean
camel.dataformat.xstream.aliases	Alias a Class to a shorter name to be used in XML elements.		List
camel.dataformat.xstream.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.xstream.converters	List of class names for using custom XStream converters. The classes must be of type com.thoughtworks.xstream.converters.Converter		List
camel.dataformat.xstream.enabled	Whether to enable auto configuration of the xstream data format. This is enabled by default.		Boolean
camel.dataformat.xstream.encoding	Sets the encoding to use		String
camel.dataformat.xstream.implicit-collections	Adds a default implicit collection which is used for any unmapped XML tag. Multiple values can be separated by comma.		List
camel.dataformat.xstream.mode	Mode for dealing with duplicate references The possible values are: NO_REFERENCES ID_REFERENCES XPATH_RELATIVE_REFERENCES XPATH_ABSOLUTE_REFERENCES SINGLE_NODE_XPATH_RELATIVE_REFERENCES SINGLE_NODE_XPATH_ABSOLUTE_REFERENCES		String
camel.dataformat.xstream.omit-fields	Prevents a field from being serialized. To omit a field you must always provide the declaring type and not necessarily the type that is converted. Multiple values can be separated by comma.		List
camel.dataformat.xstream.permissions	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 specify 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.		String

Name

Description

Default

Type

camel.dataformat.json-xstream.content-type-header

true

Boolean

camel.dataformat.json-xstream.drop-root-node

false

Boolean

camel.dataformat.json-xstream.enabled

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

Boolean

camel.dataformat.json-xstream.pretty-print

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

false

Boolean

camel.dataformat.xstream.aliases

Alias a Class to a shorter name to be used in XML elements.

List

camel.dataformat.xstream.content-type-header

true

Boolean

camel.dataformat.xstream.converters

List of class names for using custom XStream converters. The classes must be of type com.thoughtworks.xstream.converters.Converter

List

camel.dataformat.xstream.enabled

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

Boolean

camel.dataformat.xstream.encoding

Sets the encoding to use

String

camel.dataformat.xstream.implicit-collections

Adds a default implicit collection which is used for any unmapped XML tag. Multiple values can be separated by comma.

List

camel.dataformat.xstream.mode

Mode for dealing with duplicate references The possible values are: NO_REFERENCES ID_REFERENCES XPATH_RELATIVE_REFERENCES XPATH_ABSOLUTE_REFERENCES SINGLE_NODE_XPATH_RELATIVE_REFERENCES SINGLE_NODE_XPATH_ABSOLUTE_REFERENCES

String

camel.dataformat.xstream.omit-fields

Prevents a field from being serialized. To omit a field you must always provide the declaring type and not necessarily the type that is converted. Multiple values can be separated by comma.

List

camel.dataformat.xstream.permissions

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 specify 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.

String