Java Utililty Methods Iterator

List of utility methods to do Iterator

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Description

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

Method

voidcloseIterator(Iterator iterator)
Closes an iterator if it has interface ClosableIterator. 
while (iterator.hasNext()) {
    iterator.next();
intcompareRanges(final Iterator i, final Iterator j)
compare Ranges 
while (i.hasNext() && j.hasNext()) {
    final E a = i.next();
    final E b = j.next();
    final int ret = a.compareTo(b);
    if (ret != 0) {
        return ret;
if (i.hasNext()) {
    return 1;
if (j.hasNext()) {
    return -1;
return 0;
StringconcatinateElements(Iterator it)
concatinate Elements 
StringBuffer sb = new StringBuffer();
boolean first = true;
while (it.hasNext()) {
    if (!first) {
        sb.append(", ");
    Object next = it.next();
    String elm = next == null ? "<null>" : next.toString();
...
IteratorconcatIterators(final Iterator... iterators)
Concatenate a number of iterators together, to form one big iterator. 
return new Iterator<E>() {
    Iterator<E> lastIter = null;
    List<Iterator<E>> iters = new LinkedList<>(Arrays.asList(iterators));
    @Override
    public boolean hasNext() {
        return !iters.isEmpty() && iters.get(0).hasNext();
    @Override
...
StringconcatLines(Iterator lineIterator)
Concatenates several lines into one string. 
StringBuffer sb = new StringBuffer();
while (lineIterator.hasNext()) {
    String line = (String) lineIterator.next();
    if (line != null) {
        if (sb.length() != 0)
            sb.append('\n');
        sb.append(line);
return sb.length() != 0 ? sb.toString() : null;
booleancontains(final Iterator iter, final E item)
Checks if an element item is contained in the iterator sequence. 
if (iter == null || item == null) {
    throw new NullPointerException();
while (iter.hasNext()) {
    if (item.equals(iter.next())) {
        return true;
return false;
booleancontains(Iterator it, T o)
contains 
if (it == null) {
    throw new IllegalArgumentException("null it");
while (it.hasNext()) {
    if (o.equals(it.next())) {
        return true;
return false;
booleancontains(Iterator iterator, Object element)
Check whether the given Iterator contains the given element. 
if (iterator != null) {
    while (iterator.hasNext()) {
        Object candidate = iterator.next();
        if (Objects.equals(candidate, element))
            return true;
return false;
...
booleancontains(Iterator iterator, String value)
Determines if a String value is included in a Iterated list. 
if (iterator == null || value == null) {
    return false;
while (iterator.hasNext()) {
    if (value.equals(iterator.next())) {
        return true;
return false;
double[]convertToArray(Iterator iter)
convert To Array 
return listToArray(convertToList(iter));