Chapter 108. Apache Flink Component
Available as of Camel version 2.18
This documentation page covers the Apache Flink component for the Apache Camel. The camel-flink component provides a bridge between Camel connectors and Flink tasks.
This Camel Flink connector provides a way to route message from various transports, dynamically choosing a flink task to execute, use incoming message as input data for the task and finally deliver the results back to the Camel pipeline.
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-flink</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>108.1. URI Format
Currently, the Flink Component supports only Producers. One can create DataSet, DataStream jobs.
flink:dataset?dataset=#myDataSet&dataSetCallback=#dataSetCallback flink:datastream?datastream=#myDataStream&dataStreamCallback=#dataStreamCallback
FlinkEndpoint Options
The Apache Flink endpoint is configured using URI syntax:
flink:endpointType
with the following path and query parameters:
108.1.1. Path Parameters (1 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| endpointType | Required Type of the endpoint (dataset, datastream). | EndpointType |
108.1.2. Query Parameters (6 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| collect (producer) | Indicates if results should be collected or counted. | true | boolean |
| dataSet (producer) | DataSet to compute against. | DataSet | |
| dataSetCallback (producer) | Function performing action against a DataSet. | DataSetCallback | |
| dataStream (producer) | DataStream to compute against. | DataStream | |
| dataStreamCallback (producer) | Function performing action against a DataStream. | DataStreamCallback | |
| synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
108.2. Spring Boot Auto-Configuration
The component supports 6 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| camel.component.flink.data-set | DataSet to compute against. The option is a org.apache.flink.api.java.DataSet type. | String | |
| camel.component.flink.data-set-callback | Function performing action against a DataSet. The option is a org.apache.camel.component.flink.DataSetCallback type. | String | |
| camel.component.flink.data-stream | DataStream to compute against. The option is a org.apache.flink.streaming.api.datastream.DataStream type. | String | |
| camel.component.flink.data-stream-callback | Function performing action against a DataStream. The option is a org.apache.camel.component.flink.DataStreamCallback type. | String | |
| camel.component.flink.enabled | Enable flink component | true | Boolean |
| camel.component.flink.resolve-property-placeholders | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | Boolean |
108.3. FlinkComponent Options
The Apache Flink component supports 5 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| dataSet (producer) | DataSet to compute against. | DataSet | |
| dataStream (producer) | DataStream to compute against. | DataStream | |
| dataSetCallback (producer) | Function performing action against a DataSet. | DataSetCallback | |
| dataStreamCallback (producer) | Function performing action against a DataStream. | DataStreamCallback | |
| resolveProperty Placeholders (advanced) | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | boolean |
108.4. Flink DataSet Callback
@Bean
public DataSetCallback<Long> dataSetCallback() {
return new DataSetCallback<Long>() {
public Long onDataSet(DataSet dataSet, Object... objects) {
try {
dataSet.print();
return new Long(0);
} catch (Exception e) {
return new Long(-1);
}
}
};
}108.5. Flink DataStream Callback
@Bean
public VoidDataStreamCallback dataStreamCallback() {
return new VoidDataStreamCallback() {
@Override
public void doOnDataStream(DataStream dataStream, Object... objects) throws Exception {
dataStream.flatMap(new Splitter()).print();
environment.execute("data stream test");
}
};
}108.6. Camel-Flink Producer call
CamelContext camelContext = new SpringCamelContext(context);
String pattern = "foo";
try {
ProducerTemplate template = camelContext.createProducerTemplate();
camelContext.start();
Long count = template.requestBody("flink:dataSet?dataSet=#myDataSet&dataSetCallback=#countLinesContaining", pattern, Long.class);
} finally {
camelContext.stop();
}108.7. See Also
- Configuring Camel
- Component
- Endpoint
- Getting Started
