Add LongAccumulator example

Author: winterbe

src/com/winterbe/java8/samples/concurrent/LongAccumulator1.java

@@ -0,0 +1,31 @@
+package com.winterbe.java8.samples.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.LongAccumulator;
+import java.util.stream.IntStream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class LongAccumulator1 {
+
+ private static final int SIZE = 10;
+
+ private static LongAccumulator accumulator = new LongAccumulator((x, y) -> 2 * x + y, 1L);
+
+ public static void main(String[] args) {
+ testAccumulate();
+ }
+
+ private static void testAccumulate() {
+ ExecutorService executor = Executors.newFixedThreadPool(2);
+
+ IntStream.range(0, SIZE)
+ .forEach(i -> executor.submit(() -> accumulator.accumulate(i)));
+
+ ConcurrentUtils.stop(executor);
+
+ System.out.format("Add: %d\n", accumulator.getThenReset());
+ }
+}