diff --git a/core-java/0.004102810554955205 b/core-java/0.004102810554955205
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diff --git a/core-java/0.04832801936270381 b/core-java/0.04832801936270381
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diff --git a/core-java/0.5633433244738808 b/core-java/0.5633433244738808
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diff --git a/core-java/0.6256429734439612 b/core-java/0.6256429734439612
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diff --git a/core-java/0.9799201796740292 b/core-java/0.9799201796740292
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diff --git a/core-java/src/main/java/com/baeldung/streamApi/JoinerSplitter.java b/core-java/src/main/java/com/baeldung/streamApi/JoinerSplitter.java
new file mode 100644
index 0000000000..5183921dea
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/streamApi/JoinerSplitter.java
@@ -0,0 +1,23 @@
+package com.baeldung.streamApi;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class JoinerSplitter {
+
+	public static String join ( String[] arrayOfString ) {
+		return Arrays.asList(arrayOfString)
+				.stream()
+				.map(x -> x)
+				.collect(Collectors.joining(","));
+	}
+	
+	public static List<String> split ( String str ) {
+		return Stream.of(str.split(","))
+				.map (elem -> new String(elem))
+				.collect(Collectors.toList());
+	}
+	
+}
diff --git a/core-java/src/test/java/com/baeldung/stream/JoinerSplitterTest.java b/core-java/src/test/java/com/baeldung/stream/JoinerSplitterTest.java
new file mode 100644
index 0000000000..19d945f836
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/stream/JoinerSplitterTest.java
@@ -0,0 +1,38 @@
+package com.baeldung.stream;
+
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.baeldung.streamApi.JoinerSplitter;
+
+public class JoinerSplitterTest {
+
+	@Test
+	public void provided_array_convert_to_stream_and_convert_to_string() {
+		String[] programming_languages = {"java", "python", "nodejs", "ruby"};
+		String expectation = "java,python,nodejs,ruby";
+		
+		String result  = JoinerSplitter.join(programming_languages);
+		assertEquals(result, expectation);
+	}
+	
+	@Test
+	public void provided_list_convert_to_stream_and_convert_to_list() {
+		String programming_languages = "java,python,nodejs,ruby";
+		
+		List<String> expectation = new ArrayList<String>();
+		expectation.add("java");
+		expectation.add("python");
+		expectation.add("nodejs");
+		expectation.add("ruby");
+		
+		List<String> result  = JoinerSplitter.split(programming_languages);
+		
+		assertEquals(result, expectation);
+	}
+	
+}