Simplest way to create a stream from a Java object?

Question

With Collection everything is clear, but what about the following:

There is an object with a count() method and a getPart(int i) method. So extracting all objects leads to the following boilerplate code:

List<Part> result = new ArrayList<Part>();
for (int i = 0, i < object.count(), i++) {
    result.add(object.getPart(i));        
}
return result.stream();

Is there any standard way to pass just 2 producers: () -> object.count() and (int i) -> object.getPart(i) to create a stream? Like this:

SomeUtil.stream(object::count, object::getPart);

[This question](http://stackoverflow.com/questions/30685623/how-to-implement-a-streamt-for-java) seems similar, maybe it can help — Salem, Feb 28 '17 at 08:20

score 41 · Accepted Answer · answered Feb 28 '17 at 08:20

41

Try this:

IntStream.range(0, object.count()).mapToObj(object::getPart);

answered Feb 28 '17 at 08:20

MBec

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I lost track of how many times the solution to a "how do I create a stream from this weird thing"-problem was an `IntStream` solution! :D – Olle Kelderman Feb 28 '17 at 12:17

Simplest way to create a stream from a Java object?

1 Answers1