Cannot convert IntStream to some Object Stream

Question

I'm trying to use an IntStream to instantiate a stream of objects:

Stream<MyObject> myObjects = 
       IntStream
        .range(0, count)
        .map(id -> new MyObject(id));

But it says that it cannot convert MyObject to int.

rgettman · Accepted Answer · 2016-01-27 20:17:00Z

70

The IntStream class's map method maps ints to more ints, with a IntUnaryOperator (int to int), not to objects.

Generally, all streams' map method maps the type of the stream to itself, and mapToXyz maps to a different type.

Try the mapToObj method instead, which takes an IntFunction (int to object) instead.

.mapToObj(id -> new MyObject(id));

answered Jan 27, 2016 at 20:17

rgettman

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1 Comment

Or .mapToObj(MyObject::new)…

4b0 · Accepted Answer · 2019-12-11 04:37:25Z

11

Stream stream2 = intStream.mapToObj( i -> new ClassName(i));

This will convert the intstream to Stream of specified object type, mapToObj accepts a function.

There is method intStream.boxed() to convert intStream directly to Stream<Integer>

4b0

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answered Dec 11, 2019 at 4:11

sreerag

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