Sometimes when processing a Java stream() I find myself in need of a non-terminal forEach() to be used to trigger a side effect but without terminating processing.
I suspect I could do this with something like .map(item -> f(item)) where the method f performs the side effect and returns the item to the stream, but it seems a tad hokey.
Is there a standard way of handling this?
Yes there is. It is called
peek() (example from the JavaDoc):
Stream.of("one", "two", "three", "four") .peek(e -> System.out.println("Original value: " + e)) .filter(e -> e.length() > 3) .peek(e -> System.out.println("Filtered value: " + e)) .map(String::toUpperCase) .peek(e -> System.out.println("Mapped value: " + e)) .collect(Collectors.toList());