The tasks could fork more subtasks themselves . To look at this aspect, let's extend the preceding egrep program to allow a recursive grep—given a directory, the program will recursively find all occurrences of the word in all the files in the directory tree.
We change the previous code suitably, as shown here:
public class EgrepWord1 { private final static ForkJoinPool forkJoinPool = new ForkJoinPool(); private static class WordFinder extends RecursiveTask<List<String>> { final File file; final String word; private WordFinder(File file, String word) { this.file = file; this.word = word; }
The task works on two kinds of files: if it is a directory, the task enters the directory and spawns off more subtasks to process ...
