Java Utililty Methods List Intersect

int aBegin = 0;
int bBegin = 0;
while (aBegin < a.size()) {
    while (bBegin < b.size() && b.get(bBegin).intValue() < a.get(aBegin).intValue()) {
        bBegin++;
    if (bBegin < b.size() && a.get(aBegin).intValue() == b.get(bBegin).intValue()) {
        aBegin++;
...

Set<String> allWords = populateWordset(wordList1, wordList2);
Iterator<String> wordList = allWords.iterator();
while (wordList.hasNext()) {
    String word = wordList.next();
    boolean freq1 = wordList1.contains(word);
    boolean freq2 = wordList2.contains(word);
    if (freq1 && freq2) {
        return true;
...

if (collectionOfIDLists == null || collectionOfIDLists.length == 0) {
    return new ArrayList<Integer>();
final List<List<Integer>> copyListOfIDLists = new ArrayList<List<Integer>>();
for (final List<Integer> list : collectionOfIDLists) {
    copyListOfIDLists.add(new ArrayList<Integer>(list));
final List<Integer> retainedIDs = copyListOfIDLists.get(0);
...

final List<T> result = new ArrayList<T>();
for (final T elem1 : list1)
    if (list2.contains(elem1))
        result.add(elem1);
return result;

ArrayList intersection = new ArrayList();
for (int i = 0; i < list1.length; i++) {
    if (contains(list1[i], list2))
        intersection.add(list1[i]);
return arrayListToStringArray(intersection);

return null;

for (String str : list1)
    if (list2.contains(str))
        return true;
return false;

for (T n : set) {
    if (list.contains(n)) {
        return true;
return false;

if (A == null || B == null)
    return null;
List list = new ArrayList();
for (Iterator i = A.iterator(); i.hasNext();) {
    Object o = i.next();
    if (B.contains(o))
        list.add(o);
return list;

List<T> list = new ArrayList(Arrays.asList(new Object[ls.size()]));
Collections.copy(list, ls);
list.retainAll(ls2);
return list;