Learning Apache Spark 2

Passing functions to Spark (Java)

In Java, to create a function you will have to implement the interfaces available in the org.apache.spark.api.java function package. There are two popular ways to create such functions:

• Implement the interface in your own class, and pass the instance to Spark.
• Starting Java 8, you can use Lambda expressions to pass off the functions to the Spark framework.

Let's implement the preceding word count examples in Java:

Figure 2.13: Code example of Java implementation of word count (inline functions)

If you belong to a group of programmers who feel that writing inline functions makes the code complex and unreadable (a ...