Custom Thread Pools In Java 8 Parallel Streams (#1088)

* String to char array and char array to String.

* Method change

* Custom ThreadPool In Java 8 Parallel Streams

* Implemented suggested edits from editor.

* Broke long method signature

* Changed primitive type int to long and formula.

* Update wrapper type to Long

core-java/src/test/java/org/baeldung/java/streams/ThreadPoolInParallelStream.java

@@ -21,7 +21,7 @@ public class ThreadPoolInParallelStream {
         long firstNum = 1;
         long lastNum = 1_000_000;
 
-        List<Long> aList = LongStream.range(firstNum, lastNum).boxed()
+        List<Long> aList = LongStream.rangeClosed(firstNum, lastNum).boxed()
           .collect(Collectors.toList());
 
         ForkJoinPool customThreadPool = new ForkJoinPool(4);