Collection Gist

manipulating List

// Delete items while iterate
Iterator<Long> iterator = anyArrayList.iterator();
while (iterator.hasNext()) {
	long value = iterator.next();
	if (/** condition **/) {
		iterator.remove();
	}
}

// Find duplicates
boolean duplicates(final int[] zipcodelist)
{
	Set<Integer> lump = new HashSet<Integer>();
	for (int i : zipcodelist) {
   		if (lump.contains(i)) return true;
   		lump.add(i);
  	}
  	return false;
}

// Create Immutable
Integer[] values = { 1, 3, 7 };
List<Integer> list = Arrays.asList(values);

// Create Mutable
Integer[] values = { 1, 3, 7 };
List<Integer> list = new ArrayList<Integer>(Arrays.asList(values));