Add more stream examples

winterbe · winterbe · commit a3482003fd19 · 2014-07-18T08:47:30.000+02:00
diff --git a/src/com/winterbe/java8/Streams6.java b/src/com/winterbe/java8/Streams6.java
@@ -0,0 +1,99 @@
+package com.winterbe.java8;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Streams6 {
+
+    public static void main(String[] args) throws IOException {
+//        test1();
+//        test2();
+//        test3();
+//        test4();
+//        test5();
+//        test6();
+//        test7();
+        test8();
+    }
+
+    private static void test8() throws IOException {
+        Path start = Paths.get("/Users/benny/Documents");
+        int maxDepth = 5;
+        long fileCount =
+            Files
+                .walk(start, maxDepth)
+                .filter(path -> String.valueOf(path).endsWith("xls"))
+                .count();
+        System.out.format("XLS files found: %s", fileCount);
+    }
+
+    private static void test7() throws IOException {
+        Path start = Paths.get("/Users/benny/Documents");
+        int maxDepth = 5;
+        Files
+            .find(start, maxDepth, (path, attr) ->
+                String.valueOf(path).endsWith("xls"))
+            .sorted()
+            .forEach(System.out::println);
+    }
+
+    private static void test6() throws IOException {
+        Files
+            .list(Paths.get("/usr"))
+            .sorted()
+            .forEach(System.out::println);
+    }
+
+    private static void test5() throws IOException {
+        Files
+            .lines(Paths.get("/foo", "bar"))
+            .filter(line -> line.startsWith("A"))
+            .forEach(System.out::println);
+    }
+
+    private static void test4() {
+        Stream
+            .of(new BigDecimal("1.2"), new BigDecimal("3.7"))
+            .mapToDouble(BigDecimal::doubleValue)
+            .average()
+            .ifPresent(System.out::println);
+    }
+
+    private static void test3() {
+        IntStream
+            .range(0, 10)
+            .average()
+            .ifPresent(System.out::println);
+    }
+
+    private static void test2() {
+        IntStream
+            .builder()
+            .add(1)
+            .add(3)
+            .add(5)
+            .add(7)
+            .add(11)
+            .build()
+            .average()
+            .ifPresent(System.out::println);
+
+    }
+
+    private static void test1() {
+        int[] ints = {1, 3, 5, 7, 11};
+        Arrays
+            .stream(ints)
+            .average()
+            .ifPresent(System.out::println);
+    }
+}
