map vs flatMap

java-8/java-map-flatmap/src/main/java/com/javadevjournal/App.java

@@ -0,0 +1,13 @@
+package com.javadevjournal;
+
+/**
+ * Hello world!
+ *
+ */
+public class App 
+{
+    public static void main( String[] args )
+    {
+        System.out.println( "Hello World!" );
+    }
+}

java-8/java-map-flatmap/src/main/java/com/javadevjournal/FlatMapExample.java

@@ -0,0 +1,20 @@
+package com.javadevjournal;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class FlatMapExample {
+
+    public static void main(String[] args) {
+
+        List<String> words= Arrays.asList("JavaDevJournal","Java");
+        List<String> unique=  words.stream()
+               .map( s-> s.split(""))
+               .flatMap(Arrays::stream)
+               .distinct()
+               .collect(Collectors.toList());
+
+       unique.forEach(System.out::println);
+    }
+}

java-8/java-map-flatmap/src/main/java/com/javadevjournal/MapExample.java

@@ -0,0 +1,18 @@
+package com.javadevjournal;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class MapExample {
+
+    public static void main(String[] args) {
+        List<String> words= Arrays.asList("Java Dev Journal","Java", "Spring Boot","Java 8");
+
+        List<Integer> wordCount = words.stream()
+                        .map(String::length)
+                        .collect(Collectors.toList());
+
+        wordCount.forEach(System.out::println);
+    }
+}

java-8/java-map-flatmap/src/test/java/com/javadevjournal/AppTest.java

@@ -0,0 +1,20 @@
+package com.javadevjournal;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+/**
+ * Unit test for simple App.
+ */
+public class AppTest 
+{
+    /**
+     * Rigorous Test :-)
+     */
+    @Test
+    public void shouldAnswerWithTrue()
+    {
+        assertTrue( true );
+    }
+}