Stream

Implementation of simplified and modified version of Java Stream API with lazy evaluation.

Dependency

This project is distributed via JitPack. Register a JitPack repository at your pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

And add the following dependency:

<dependency>
    <groupId>com.github.jolice</groupId>
    <artifactId>Stream</artifactId>
    <version>v1.0</version>
</dependency>

Creating a stream

StreamFactory class is responsible for creating streams.

A stream may be constructed from fixed list of elements:

Stream<String> stream = StreamFactory.of("alpha", "bravo", "charlie", "delta", "echo");

Or from any Iterable implementation:

List<String> list = Arrays.asList("alpha", "bravo", "charlie", "delta", "echo");
Stream<String> stream = StreamFactory.of(list);

Empty stream may be created as follows:

Stream<String> stream = StreamFactory.empty();

Infinite streams are also supported:

Stream<Integer> stream = StreamFactory.iterate(1, i -> i + 1).limit(5);

Operations

Operations inherited from Java 8 Stream interface

• Iterator
• Filter
• Map
• FlatMap
• Distinct
• Sorted
• Peek
• Limit
• Skip
• ForEach
• ToArray
• Reduce
• Collect
• Min
• Max
• Count
• AnyMatch
• AllMatch
• NoneMatch
• FindAny

Custom operations

TakeWhile skips all elements after the first one that doesn't match a predicate:

StreamFactory.of(1,2,3,4,5,6).takeWhile(x -> x <= 3)
       .collect(Collectors.toList()); // [1,2,3]

DropWhile skips all elements before the first one that matches a predicate:

 StreamFactory.of(6,5,4,3,2,1).dropWhile(x -> x > 3)
       .collect(Collectors.toList()); // [3,2,1]

FiterNot filters out the elements that match the predicate, inverse for Filter:

StreamFactory.of(1,2,3,4,5,6).filterNot(x -> x % 2 == 0)
        .collect(Collectors.toList()); // [1,3,5]

FilterNulls filters out null items:

StreamFactory.of(1, 2, null, 4, null, 6).filterNulls()
        .collect(Collectors.toList()); // [1, 2, 4, 6]

Not supported operations

• Parallel
• MapToInt / Double / Long
• FlatMapToInt / Double / Long
• ForEachOrdered