Add Java vs Vavr Stream sample

k0l0ssus · web-flow · commit 4d8f0a48ae28 · 2018-01-28T18:06:11.000-05:00
diff --git a/vavr/src/main/java/com/baeldung/samples/java/vavr/VavrSampler.java b/vavr/src/main/java/com/baeldung/samples/java/vavr/VavrSampler.java
@@ -0,0 +1,99 @@
+package com.baeldung.samples.java.vavr;
+
+import io.vavr.collection.Stream;
+import java.util.ArrayList;
+import java.util.List;
+
+
+/**
+ *
+ * @author baeldung
+ */
+public class VavrSampler {
+
+    static int[] intArray = new int[]{1, 2, 4};
+    static List<Integer> intList = new ArrayList<Integer>();
+    static int[][] intOfInts = new int[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
+
+    public static void main(String[] args) {
+       vavrStreamElementAccess();
+        System.out.println("====================================");
+        vavrParallelStreamAccess();
+        System.out.println("====================================");
+        vavrFlatMapping();
+        System.out.println("====================================");
+        vavrStreamManipulation();
+        System.out.println("====================================");
+        vavrStreamDistinct();
+    }
+
+    public static void vavrStreamElementAccess() {
+        System.out.println("Vavr Element Access");
+        System.out.println("====================================");
+        Stream<Integer> vavredStream = Stream.ofAll(intArray);
+        System.out.println("Vavr index access: " + vavredStream.get(2));
+        System.out.println("Vavr head element access: " + vavredStream.get());
+
+        Stream<String> vavredStringStream = Stream.of("foo", "bar", "baz");
+        System.out.println("Find foo " + vavredStringStream.indexOf("foo"));
+    }
+
+    public static void vavrParallelStreamAccess() {
+
+        System.out.println("Vavr Stream Concurrent Modification");
+        System.out.println("====================================");
+        Stream<Integer> vavrStream = Stream.ofAll(intList);
+        //intList.add(5);
+        vavrStream.forEach(i -> System.out.println("in a Vavr Stream: " + i));
+
+//        Stream<Integer> wrapped = Stream.ofAll(intArray);
+//        intArray[2] = 5;
+//        wrapped.forEach(i -> System.out.println("Vavr looped " + i));
+    }
+
+    public static void jdkFlatMapping() {
+        System.out.println("Java flatMapping");
+        System.out.println("====================================");
+        java.util.stream.Stream.of(42).flatMap(i -> java.util.stream.Stream.generate(() -> {
+            System.out.println("nested call");
+            return 42;
+        })).findAny();
+    }
+
+    public static void vavrFlatMapping() {
+        System.out.println("Vavr flatMapping");
+        System.out.println("====================================");
+        Stream.of(42)
+                .flatMap(i -> Stream.continually(() -> {
+            System.out.println("nested call");
+            return 42;
+        }))
+                .get(0);
+    }
+
+    public static void vavrStreamManipulation() {
+        System.out.println("Vavr Stream Manipulation");
+        System.out.println("====================================");
+        List<String> stringList = new ArrayList<>();
+        stringList.add("foo");
+        stringList.add("bar");
+        stringList.add("baz");
+        Stream<String> vavredStream = Stream.ofAll(stringList);
+        vavredStream.forEach(item -> System.out.println("Vavr Stream item: " + item));
+        Stream<String> vavredStream2 = vavredStream.insert(2, "buzz");
+        vavredStream2.forEach(item -> System.out.println("Vavr Stream item after stream addition: " + item));
+        stringList.forEach(item -> System.out.println("List item after stream addition: " + item));
+        Stream<String> deletionStream = vavredStream.remove("bar");
+        deletionStream.forEach(item -> System.out.println("Vavr Stream item after stream item deletion: " + item));
+
+    }
+
+    public static void vavrStreamDistinct() {
+        Stream<String> vavredStream = Stream.of("foo", "bar", "baz", "buxx", "bar", "bar", "foo");
+        Stream<String> distinctVavrStream = vavredStream.distinctBy((y, z) -> {
+            return y.compareTo(z);
+        });
+        distinctVavrStream.forEach(item -> System.out.println("Vavr Stream item after distinct query " + item));
+
+    }
+}
