JavaQuestions.java

public class JavaQuestions {

    public willCompileOrNot() {
        https://www.github.com/peterszatmary/
        System.out.println("will compile or not ?");
    }
        
    public void question1() {
        System.out.println(null);
    }    
        
    public void question2() {
        Integer in = null;
        Integer v = in.valueOf(100);
        System.out.println("v = " + v);
    }       
        
    public void recursiveWalker(File file) {
        System.out.println(file.getAbsolutePath());
        File[] children = file.listFiles();
        if (null != children) {
            for (File child : children) {
                recursiveWalker(child);
            }
        }
    }
    
    public static nonRecursiveWalker(String path, int d) {
        File root = new File(path);
        List<File> ex = new LinkedList<>();
        ex.add(root);

        for (int depth = 0; depth < d; depth++) {
            File[] fs = ex.toArray(new File[ex.size()]);
            ex.clear();
            for (File file: fs) {
                System.out.println("depth = " + depth + ", file = " + file);
                if (file.isDirectory()) {
                    ex.addAll(Arrays.asList(file.listFiles()));
                }
            }
        }
    }
   
    public boolean isAcyclic(String s1, String s2) {
        return (s1 != null && s2 != null) && (s1.length() == s2.length()) && ((s1 + s1).indexOf(s2) != -1);
    }
    
    public void howLong() {
        long start = System.nanoTime();
        // computation
        long end = System.nanoTime();
        System.out.println("time: " + (end - start) + " ns");
    }
}