Java Utililty Methods List Union

List of utility methods to do List Union

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Description

The list of methods to do List Union are organized into topic(s).

Method

Listunion(List list1, List list2, boolean duplicate)
union 
if (list1 == null || list2 == null) {
    return (list1 == null) ? new ArrayList<T>(list2) : new ArrayList<T>(list1);
List<T> ret;
if (duplicate) {
    ret = new ArrayList<T>(list1);
    ret.addAll(list2);
} else {
...
Listunion(List set1, List set2)
union 
List<T> unionSet = new ArrayList<T>(set1);
unionSet.addAll(set2);
return unionSet;
Listunion(List... lists)
Creates a union from all of the specified List s. 
List<T> newList = new LinkedList<>();
for (List<T> list : lists) {
    newList.addAll(list);
return newList;
voidunionAdd(List vect, E obj)

This method adds obj to vect if and only if vect does not already contain obj.

if (obj == null) {
    return;
if (vect.contains(obj)) {
    return;
vect.add(obj);
StringunionCreditList(List list)
Creates the union of a list of credit ranges, returning the min and max credits found. 
if (list == null || list.isEmpty())
    return "";
float minCredits = Integer.MAX_VALUE;
float maxCredits = Integer.MIN_VALUE;
for (String item : list) {
    String[] split = item.split("[ ,/-]");
    String first = split[0];
    float min = Float.parseFloat(first);
...
ListunionList(Collection col1, Collection col2)
union List 
List<T> result = new ArrayList<>(col1.size() + col2.size());
result.addAll(col1);
result.addAll(col2);
return result;
ListunionList(List la, List lb)
union List 
if (la == null) {
    la = new ArrayList<T>();
if (lb == null) {
    lb = new ArrayList<T>();
List<T> cpLa = new ArrayList<T>();
List<T> cpLb = new ArrayList<T>();
...
ListunionList(List list1, List list2)
Union list. 
if (isEmpty(list1) && isEmpty(list2)) {
    return new ArrayList<T>();
if (isEmpty(list1) && !isEmpty(list2)) {
    return list2;
if (!isEmpty(list1) && isEmpty(list2)) {
    return list1;
...
SetunionOfListOfLists(final Collection> collectionOfCollection)
union Of List Of Lists 
if (collectionOfCollection == null || collectionOfCollection.isEmpty()) {
    return Collections.emptySet();
final HashSet<T> union = new HashSet<T>();
for (final Collection<T> col : collectionOfCollection) {
    if (col != null) {
        for (final T t : col) {
            if (t != null) {
...
StringunionSeparator(List elements, String separator)
union Separator 
final StringBuilder sb = new StringBuilder();
sb.append(elements.get(0));
for (int i = 1; i < elements.size(); i++) {
    sb.append(separator);
    sb.append(elements.get(i));
return sb.toString();