Started implementing grouping opperators.

Author: brettryan

src/main/java/com/drunkendev/lambdas/GroupingOperators.java

@@ -0,0 +1,82 @@
+/*
+ * GroupingOperators.java    Feb 3 2014, 05:55
+ *
+ * Copyright 2014 Drunken Dev.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.drunkendev.lambdas;
+
+import com.drunkendev.lambdas.domain.DomainService;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.stream;
+
+
+/**
+ *
+ * @author  Brett Ryan
+ */
+public class GroupingOperators {
+
+    private final DomainService ds;
+
+    /**
+     * Creates a new {@code GroupingOperators} instance.
+     */
+    public GroupingOperators() {
+        this.ds = new DomainService();
+    }
+
+    public static void main(String[] args) {
+        GroupingOperators go = new GroupingOperators();
+        go.lambda40();
+        go.lambda41();
+        go.lambda42();
+        go.lambda43();
+        go.lambda44();
+        go.lambda45();
+    }
+
+    public void lambda40() {
+        int[] numbers = {5, 4, 1, 3, 9, 8, 6, 7, 2, 0};
+        Map<Integer, List<Integer>> map = stream(numbers)
+                .boxed()
+                .collect(Collectors.groupingBy(n -> n % 5));
+        for (Entry<Integer, List<Integer>> ent : map.entrySet()) {
+            System.out.println(String.format(
+                    "Numbers with a remainder of %d when divided by 5:", ent.getKey()));
+            ent.getValue().stream().forEach(System.out::println);
+        }
+    }
+
+    public void lambda41() {
+    }
+
+    public void lambda42() {
+    }
+
+    public void lambda43() {
+    }
+
+    public void lambda44() {
+    }
+
+    public void lambda45() {
+    }
+
+}