changing package structure (#1157)

* rest with spark java

* 4

* Update Application.java

* indentation changes

* spring @requestmapping shortcuts

* removing spring requestmapping and pushing spring-mvc-java

* Joining/Splitting Strings with Java and Stream API

* adding more join/split functionality

* changing package name

* testcase change

core-java/src/main/java/com/baeldung/string/JoinerSplitter.java

@@ -0,0 +1,36 @@
+package com.baeldung.string;
+
+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 String joinWithPrefixPostFix ( 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());
+	}
+	
+	public static List<Character> splitToListOfChar ( String str ) {
+		return str.chars()
+				.mapToObj(item -> (char) item)
+				.collect(Collectors.toList());
+	}
+		
+}

core-java/src/test/java/com/baeldung/string/JoinerSplitterTest.java

@@ -0,0 +1,65 @@
+package com.baeldung.string;
+
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.baeldung.string.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_array_convert_to_stream_and_convert_to_prefixPostfix() {
+		String[] programming_languages = {"java", "python", 
+				"nodejs", "ruby"};
+		String expectation = "[java,python,nodejs,ruby]";
+		
+		String result  = JoinerSplitter.joinWithPrefixPostFix(programming_languages);
+		assertEquals(result, expectation);
+	}
+	
+	@Test
+	public void provided_string_convert_to_stream_and_convert_to_listOfString() {
+		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);
+	}
+  
+	@Test
+	public void provided_string_convert_to_stream_and_convert_to_listOfChar() {
+		String programming_languages = "java,python,nodejs,ruby";
+		
+		List<Character> expectation = new ArrayList<Character>();
+		char[] charArray = programming_languages.toCharArray();
+		for (char c : charArray) {
+			expectation.add(c);
+		}
+		
+		List<Character> result  = JoinerSplitter.splitToListOfChar(programming_languages);
+		assertEquals(result, expectation);
+		
+	}
+  
+}