Java Utililty Methods Stream Operation

List of utility methods to do Stream Operation

  1. HOME
  2. Java
  3. S
  4. Stream Operation

Description

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

Method

booleanstartsWith(Stream stream, Iterable iterable)
   assertTrue(StreamUtils.startsWith(Stream.of(1,2,3,4),Arrays.asList(1,2,3))); 
return startsWith(stream, iterable.iterator());
booleanstartsWith(Stream stream, Stream stream2)
starts With 
return startsWith(stream, stream2.iterator());
StreamstringPositions(StringBuilder toTest, Stream strings)
Tests the supplied StringBuilder for the presence of strings , and returns the positions of matching characters. 
if (toTest == null) {
    throw new IllegalArgumentException("StringBuilder must not be null.");
if (strings == null) {
    throw new IllegalArgumentException("Invalid strings must not be null");
Stream.Builder<Integer> positionStream = Stream.builder();
strings.forEach(invalidString -> {
...
ListtoList(final Stream stream)
to List 
return stream.collect(Collectors.toList());
StreamtoParameter(Stream input, Class exp)
to Parameter 
return input.map(s -> new Object[] { s, exp });
StringtoString(IntStream s)
to String 
return s.mapToObj(String::valueOf).collect(Collectors.joining());
StringtoString(LongStream ls)
Consumes all the values provided by the passed LongStream, displaying them as an array of values (on a single line). 
StringBuilder sb = new StringBuilder("[");
ls.peek(sb::append).peek(n -> sb.append(", ")).filter(n -> false).findAny();
String output = sb.substring(0, sb.length() - 2);
return output + "]";
StreamupcastStream(Stream stream)
upcast Stream 
return (Stream<T>) stream;
Stream>zip(List> streams)
Convert a List of Stream into a Stream of List by associating each element of one list with the element at the same position in the latters. 
final List<Iterator<T>> iteratorsList = streams.stream().map(Stream::iterator).collect(Collectors.toList());
final Iterator<List<T>> zippedIterator = new Iterator<List<T>>() {
    @Override
    public boolean hasNext() {
        for (Iterator<T> it : iteratorsList)
            if (it.hasNext())
                return true;
        return false;
...
Stream>zipWithIndex(Stream stream, int startIndex)
Zips the specified stream with its indices. 
return iterate(new Iterator<Map.Entry<Integer, T>>() {
    private final Iterator<? extends T> streamIterator = stream.iterator();
    private int index = startIndex;
    @Override
    public boolean hasNext() {
        return streamIterator.hasNext();
    @Override
...