Java™ How To Program (Early Objects), Tenth Edition

17.3.4 Intermediate Operations: Filtering and Sorting IntStream Values

Lines 45–48 of Fig. 17.5 create a stream pipeline that locates the even integers in an IntStream, sorts them in ascending order and displays each value followed by a space.

Intermediate Operation filter

You filter elements to produce a stream of intermediate results that match a condition—known as a predicate. IntStream method filter (line 46) receives an object that implements the IntPredicate functional interface (package java.util.function). The lambda in line 46:

value -> value % 2 == 0

implements the interface’s test method, which receives an int and returns a boolean indicating whether the int satisfies the predicate—in this case, the IntPredicate returns true ...