rspec/rules/S3631/java/rule.adoc

== Why is this an issue?

For arrays of objects, ``++Arrays.asList(T ... a).stream()++`` and ``++Arrays.stream(array)++`` are basically equivalent in terms of performance. However, for arrays of primitives, using ``++Arrays.asList++`` will force the construction of a list of boxed types, and then use _that_ list as a stream. On the other hand, ``++Arrays.stream++`` uses the appropriate primitive stream type (``++IntStream++``, ``++LongStream++``, ``++DoubleStream++``) when applicable, with much better performance.


=== Noncompliant code example

[source,java]
----
Arrays.asList("a1", "a2", "b1", "c2", "c1").stream()
    .filter(...)
    .forEach(...);

Arrays.asList(1, 2, 3, 4).stream() // Noncompliant
    .filter(...)
    .forEach(...);
----


=== Compliant solution

[source,java]
----
Arrays.asList("a1", "a2", "b1", "c2", "c1").stream()
    .filter(...)
    .forEach(...);

int[] intArray = new int[]{1, 2, 3, 4};
Arrays.stream(intArray)
    .filter(...)
    .forEach(...);
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Use "Arrays.stream" instead of "Arrays.asList".


=== Highlighting

``++Arrays.asList++``


endif::env-github,rspecator-view[]