YAML SnakeYAML
Since Camel 2.17
YAML is a Data Format to marshal and unmarshal Java objects to and from YAML.
For YAML to object marshalling, Camel provides integration with three popular YAML libraries:
-
The SnakeYAML library
Every library requires adding the special camel component (see "Dependency…" paragraphs further down). By default Camel uses the SnakeYAML library.
YAML Options
The YAML SnakeYAML dataformat supports 12 options, which are listed below.
| Name | Default | Java Type | Description |
|---|---|---|---|
|
| Which yaml library to use. By default it is SnakeYAML. Enum values:
| |
| Class name of the java type to use when unmarshalling. | ||
| BaseConstructor to construct incoming documents. | ||
| Representer to emit outgoing objects. | ||
| DumperOptions to configure outgoing objects. | ||
| Resolver to detect implicit type. | ||
|
| Use ApplicationContextClassLoader as custom ClassLoader. | |
|
| Force the emitter to produce a pretty YAML document when using the flow style. | |
|
| Allow any class to be un-marshaled. | |
| Set the types SnakeYAML is allowed to un-marshall. | ||
|
| Set the maximum amount of aliases allowed for collections. | |
|
| Set whether recursive keys are allowed. |
| SnakeYAML can load any class from YAML definition which may lead to security breach so by default, SnakeYAML DataForma restrict the object it can load to standard Java objects like List or Long. If you want to load custom POJOs you need to add theirs type to SnakeYAML DataFormat type filter list. If your source is trusted, you can set the property allowAnyType to true so SnakeYAML DataForma won’t perform any filter on the types. |
Using YAML data format with the SnakeYAML library
-
Turn Object messages into yaml then send to MQSeries
from("activemq:My.Queue") .marshal().yaml() .to("mqseries:Another.Queue");from("activemq:My.Queue") .marshal().yaml(YAMLLibrary.SnakeYAML) .to("mqseries:Another.Queue"); -
Restrict classes to be loaded from YAML
// Creat a SnakeYAMLDataFormat instance SnakeYAMLDataFormat yaml = new SnakeYAMLDataFormat(); // Restrict classes to be loaded from YAML yaml.addTypeFilters(TypeFilters.types(MyPojo.class, MyOtherPojo.class)); from("activemq:My.Queue") .unmarshal(yaml) .to("mqseries:Another.Queue");
Using YAML in Spring DSL
When using Data Format in Spring DSL, you need to declare the data formats first. This is done in the DataFormats XML tag.
<dataFormats>
<!--
here we define a YAML data format with the id snake and that it should use
the TestPojo as the class type when doing unmarshal. The unmarshalType
is optional
-->
<yaml
id="snake"
library="SnakeYAML"
unmarshalType="org.apache.camel.component.yaml.model.TestPojo"/>
<!--
here we define a YAML data format with the id snake-safe which restricts the
classes to be loaded from YAML to TestPojo and those belonging to package
com.mycompany
-->
<yaml id="snake-safe">
<typeFilter value="org.apache.camel.component.yaml.model.TestPojo"/>
<typeFilter value="com.mycompany\..*" type="regexp"/>
</yaml>
</dataFormats>And then you can refer to those ids in the route:
<route>
<from uri="direct:unmarshal"/>
<unmarshal>
<custom ref="snake"/>
</unmarshal>
<to uri="mock:unmarshal"/>
</route>
<route>
<from uri="direct:unmarshal-safe"/>
<unmarshal>
<custom ref="snake-safe"/>
</unmarshal>
<to uri="mock:unmarshal-safe"/>
</route>Dependencies for SnakeYAML
To use YAML in your camel routes, you need to add a dependency on camel-snakeyaml 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 release (see the download page for the latest versions).
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-snakeyaml</artifactId>
<version>${camel-version}</version>
</dependency>Spring Boot Auto-Configuration
When using snakeYaml 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-snakeyaml-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>The component supports 11 options, which are listed below.