Available as of Camel 2.18

This documentation page covers the https://flink.apache.org 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>

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

You can append query options to the URI in the following format, ?option=value&option=value&...

Name

Default Value

Description

endpointType

 Required Type of the endpoint (dataset datastream).

collect

trueIndicates if results should be collected or counted.

dataSet

 DataSet to compute against.
dataSetCallback Function performing action against a DataSet.
dataStream DataStream to compute against.
dataStreamCallback Function performing action against a DataStream.
exchangePatternInOnlySets the default exchange pattern when creating an exchange
synchronous Sets whether synchronous processing should be strictly used or Camel is allowed to use asynchronous processing (if supported).

Name

Default Value

Description

dataSet

 DataSet to compute against.

dataStream

 DataStream to compute against.
dataSetCallback Function performing action against a DataSet.
dataStreamCallback Function performing action against a DataStream.

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);
            }
        }
    };
}

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");
        }
    };
}

Flink Producer 

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();
}

 

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