DFDL

Since Camel 4.11

Only producer is supported

The DFDL component allows you to transform the fixed format data such as EDI message from/to XML using Data Format Description Language, also known as DFDL. DFDL schema is an XML schema annotated with DFDL elements and attributes.

While DFDL schema defines the XML representation of the data structure, it also defines how the conversion between the fixed format and XML is processed using DFDL annotations.

This component uses Apache Daffodil as an underlying DFDL implementation.

URI format

dfdl:schemaUri[?options]

The URI format contains schemaUri, which can be the classpath-local URI of the DFDL schema file.

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The DFDL component supports 2 options, which are listed below.

Name Description Default Type

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

Endpoint Options

The DFDL endpoint is configured using URI syntax:

dfdl:schemaUri

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

schemaUri (producer)

Required The path to the DFDL schema file.

String

Query Parameters (4 parameters)

Name Description Default Type

parseDirection (producer)

Transform direction. Either PARSE or UNPARSE.

Enum values:

  • PARSE

  • UNPARSE

PARSE

ParseDirection

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

rootElement (advanced)

The root element name of the schema to use. If not specified, the first root element in the schema will be used.

String

rootNamespace (advanced)

The root namespace of the schema to use.

String

/ component headers: START

Using DFDL endpoints

The following format is an example of using DFDL to convert an EDI message to an XML using X12-837P-dfdl.xsd DFDL schema file.

from("direct:parse").
  to("dfdl:X12-837P.dfdl.xsd");

The following format is an example of using DFDL to convert an XML to an EDI message using X12-837P-dfdl.xsd DFDL schema file. Note that UNPARSE is specified for the parseDirection parameter.

from("direct:unparse").
  to("dfdl:X12-837P.dfdl.xsd?parseDirection=UNPARSE");

Spring Boot Auto-Configuration

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

The component supports 7 options, which are listed below.

Name Description Default Type

camel.component.dfdl.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.dfdl.enabled

Whether to enable auto configuration of the dfdl component. This is enabled by default.

Boolean

camel.component.dfdl.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.dataformat.dfdl.enabled

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

Boolean

camel.dataformat.dfdl.root-element

The root element name of the schema to use. If not specified, the first root element in the schema will be used.

String

camel.dataformat.dfdl.root-namespace

The root namespace of the schema to use.

String

camel.dataformat.dfdl.schema-uri

The path to the DFDL schema file.

String
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