[Feature Request]: Implement SparkReceiverIO connector for Java

What would you like to happen?

As a user, I want to be able to use Spark Streaming Custom Receiver as a resource for reading data in the Apache Beam pipeline. Spark Streaming Custom Receivers can be written for any service.

TODOs:

  • Implementation of reading from Spark Streaming Custom Receiver via SDF
  • Unit Tests written
  • Integration Tests for SparkReceiverIO written
  • SparkReceiverIO Documentation written

Issue Priority

Priority: 2 (default / most feature requests should be filed as P2)

Issue Components

io-java-cdap