Add parallelStream examples

winterbe · winterbe · commit 38061648cca4 · 2014-07-23T09:03:41.000+02:00
diff --git a/src/com/winterbe/java8/Streams12.java b/src/com/winterbe/java8/Streams12.java
@@ -0,0 +1,57 @@
+package com.winterbe.java8;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Streams12 {
+
+    public static void main(String[] args) {
+        List<String> strings = Arrays.asList("a1", "a2", "b1", "c2", "c1");
+
+//        test1(strings);
+//        test2(strings);
+        test3(strings);
+    }
+
+    private static void test3(List<String> strings) {
+        strings
+            .parallelStream()
+            .filter(s -> {
+                System.out.format("filter:  %s [%s]\n", s, Thread.currentThread().getName());
+                return true;
+            })
+            .map(s -> {
+                System.out.format("map:     %s [%s]\n", s, Thread.currentThread().getName());
+                return s.toUpperCase();
+            })
+            .sorted((s1, s2) -> {
+                System.out.format("sort:    %s <> %s [%s]\n", s1, s2, Thread.currentThread().getName());
+                return s1.compareTo(s2);
+            })
+            .forEach(s -> System.out.format("forEach: %s [%s]\n", s, Thread.currentThread().getName()));
+    }
+
+    private static void test2(List<String> strings) {
+        strings
+            .parallelStream()
+            .filter(s -> {
+                System.out.format("filter:  %s [%s]\n", s, Thread.currentThread().getName());
+                return true;
+            })
+            .map(s -> {
+                System.out.format("map:     %s [%s]\n", s, Thread.currentThread().getName());
+                return s.toUpperCase();
+            })
+            .forEach(s -> System.out.format("forEach: %s [%s]\n", s, Thread.currentThread().getName()));
+    }
+
+    private static void test1() {
+        // -Djava.util.concurrent.ForkJoinPool.common.parallelism=5
+
+//        ForkJoinPool commonPool = ForkJoinPool.commonPool();
+//        System.out.println(commonPool.getParallelism());
+    }
+}
