Smooks
Since Camel 4.7
Only producer is supported
The Camel Smooks component uses Smooks to break up the structured data (EDI, CSV, POJO, etc…) of a Camel message body into fragments. These fragments can be processed independently of one another from within Smooks.
Common applications of Smooks include:
-
transformation: EDI to CSV, POJO to EDI, POJO to XML, and so on.
-
scalable processing: process huge payloads while keeping a small memory footprint. Split, transform, and route fragments to destinations such as JMS queues, file systems, and databases.
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enrichment: enrich fragments with data from a database or other data sources.
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Java binding: populate POJOs from a source such as CSV, EDI, XML, and other POJOs.
Use the Smooks Data Format instead of this component when you are primarily interested in transformation and binding; not other Smooks features like routing.
Maven users will need to add the following dependency to their pom.xml
.
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-smooks</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
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 Smooks component supports 3 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
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 | |
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 | |
Autowired To use a custom factory for creating Smooks. | SmooksFactory |
Endpoint Options
The Smooks endpoint is configured using URI syntax:
smooks:smooksConfig
With the following path and query parameters:
Query Parameters (3 parameters)
Name | Description | Default | Type |
---|---|---|---|
File path to place the generated HTML execution report. The report is a useful tool in the developers arsenal for diagnosing issues or comprehending a transformation. Do not set in production since this is a major performance drain. | String | ||
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 | |
Allow execution context to be set from the CamelSmooksExecutionContext header. | false | Boolean |
Message Headers
The Smooks component supports 1 message header(s), which is/are listed below:
Name | Description | Default | Type |
---|---|---|---|
CamelSmooksExecutionContext (advanced) Constant: | The Smooks execution context. | ExecutionContext |
Usage
Using the Smooks component lets you leverage all the features of Smooks, such as transformation and fragment-driven routing, from within Camel. You can take an existing Smooks configuration and use this in your Camel routes as shown below:
-
Java
-
YAML
from("file:inputDir?noop=true")
.to("smooks:smooks-config.xml")
.to("jms:queue:order");
- from:
uri: file:inputDir?noop=true
steps:
- to: smooks:smooks-config.xml
- to: jms:queue:order
The Smooks component is configured with a mandatory configuration file, which is smooks-config.xml
in the example above. It is not clear what type of output the component is producing from looking at the above route. By default, the message body output is a stream but the type of output can be changed by configuring {https://www.smooks.org/xsd/smooks/smooks-core-1.6.xsd}exports
in smooks-config.xml
as shown in this Smooks configuration:
<smooks-resource-list xmlns="https://www.smooks.org/xsd/smooks-2.0.xsd"
xmlns:edi="https://www.smooks.org/xsd/smooks/edi-2.0.xsd"
xmlns:core="https://www.smooks.org/xsd/smooks/smooks-core-1.6.xsd">
<core:exports>
<core:result type="org.smooks.io.sink.StringSink"/>
</core:exports>
<edi:parser schemaUri="/edi-mapping-model.dfdl.xsd" segmentTerminator="%NL;" dataElementSeparator="*"
compositeDataElementSeparator="^"/>
</smooks-resource-list>
The example <core:exports>
configures Smooks to export the execution result to Camel as a string. Keep in mind that exporting the result as string means that the whole result will be kept in-memory which could cause unexpected performance issues for large payloads.