Consider two code snippets as the following:
// Java code:
abstract class Ops implements Serializable{
public abstract Integer apply(Integer x);
public void doSomething(JavaRDDInteger rdd) {
rdd.map(x - x + apply(x))
.collect()
.forEach(System.out::println);
}
}
public
The difference is really that Java and Scala work differently. In
Java, your anonymous subclass of Ops defined in (a method of)
AbstractTest captures a reference to it. That much is 'correct' in
that it's how Java is supposed to work, and AbstractTest is indeed not
serializable since you didn't
