RandomAccessWrite.java

final Semaphore s = new Semaphore(10);

final Stopwatch w = Stopwatch.createStarted();
final File t = Files.createTempDir();
try {
    for (int i = 0; i < 10000; i++) {
        s.acquire();
        final RandomAccessFile file = new RandomAccessFile(new File(t, "f" + i + ".txt"), "rw");
        file.write("HELLO WORLD".getBytes(Charsets.UTF_8));
        file.close();
        s.release();
    }
    w.stop();
    System.out.println("Done in " + w);
} finally {
    for (File file : Files.fileTreeTraverser().breadthFirstTraversal(t)) {
        file.delete();
    }
}