Stream API call chain can be simplified
Reports stream API call chains that can be simplified. Simplification will often avoid some temporary object creation during collection traversal.
The inspection replaces the following call chains:
collection.stream().forEach()
→collection.forEach()
collection.stream().collect(toList/toSet/toCollection())
→new CollectionType<>(collection)
collection.stream().toArray()
→collection.toArray()
Arrays.asList().stream()
→Arrays.stream()
orStream.of()
IntStream.range(0, array.length).mapToObj(idx -> array[idx])
→Arrays.stream(array)
IntStream.range(0, list.size()).mapToObj(idx -> list.get(idx))
→list.stream()
Collections.singleton().stream()
→Stream.of()
Collections.emptyList().stream()
→Stream.empty()
stream.filter().findFirst().isPresent()
→stream.anyMatch()
stream.collect(counting())
→stream.count()
stream.collect(maxBy())
→stream.max()
stream.collect(mapping())
→stream.map().collect()
stream.collect(reducing())
→stream.reduce()
stream.collect(summingInt())
→stream.mapToInt().sum()
stream.mapToObj(x -> x)
→stream.boxed()
stream.map(x -> {...; return x;})
→stream.peek(x -> ...)
!stream.anyMatch()
→stream.noneMatch()
!stream.anyMatch(x -> !(...))
→stream.allMatch()
stream.map().anyMatch(Boolean::booleanValue)
→stream.anyMatch()
IntStream.range(expr1, expr2).mapToObj(x -> array[x])
→Arrays.stream(array, expr1, expr2)
Collection.nCopies(count, ...)
→Stream.generate().limit(count)
stream.sorted(comparator).findFirst()
→Stream.min(comparator)
optional.orElseGet(() -> { throw new ...; })
→optional.orElseThrow()
Note that the replacement semantics may have minor differences in some cases. For example, Collections.synchronizedList(...).stream().forEach()
is not synchronized while Collections.synchronizedList(...).forEach()
is synchronized. Also, collect(Collectors.maxBy())
returns an empty Optional
if the resulting element is null
while Stream.max()
throws NullPointerException
in this case.
- By ID
Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.
SimplifyStreamApiCallChains
This inspection depends on the Java feature 'Stream and Optional API', which is available since Java 8.
Inspection Details | |
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By default bundled with: | |
Can be installed with plugin: | Java, 243.23126 |
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