From bd2ed439612a0e96e25a4a05ad684f838e72fdea Mon Sep 17 00:00:00 2001
From: sam-gardner <53271849+sam-gardner@users.noreply.github.com>
Date: Sat, 18 Feb 2023 04:23:54 +0000
Subject: [PATCH] =?UTF-8?q?BAEL-6100-Add-example-code-for-integer-array-to?=
 =?UTF-8?q?-strings-using-streams=E2=80=A6=20(#13375)?=
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* BAEL-6100-Add-example-code-for-integer-array-to-strings-using-streams-tutorial

* BAEL-6100 remove wrongly added README update

* BAEL-6100 Add interger array to single string example

* BAEL-6100 Correct typo in test class name
---
 .../ArrayConversionUtils.java                 | 43 +++++++++++++++
 .../IntArrayToStringUnitTest.java             | 52 +++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 core-java-modules/core-java-streams-4/src/main/java/com/baeldung/streams/intarraytostrings/ArrayConversionUtils.java
 create mode 100644 core-java-modules/core-java-streams-4/src/test/java/com/baeldung/streams/intarraytostrings/IntArrayToStringUnitTest.java

diff --git a/core-java-modules/core-java-streams-4/src/main/java/com/baeldung/streams/intarraytostrings/ArrayConversionUtils.java b/core-java-modules/core-java-streams-4/src/main/java/com/baeldung/streams/intarraytostrings/ArrayConversionUtils.java
new file mode 100644
index 0000000000..3bb58b43d2
--- /dev/null
+++ b/core-java-modules/core-java-streams-4/src/main/java/com/baeldung/streams/intarraytostrings/ArrayConversionUtils.java
@@ -0,0 +1,43 @@
+package com.baeldung.streams.intarraytostrings;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class ArrayConversionUtils {
+
+    public static void createStreamExample() {
+        int[] intArray = { 1, 2, 3, 4, 5 };
+        IntStream intStream = Arrays.stream(intArray);
+
+        Integer[] integerArray = { 1, 2, 3, 4, 5 };
+        Stream<Integer> integerStream = Arrays.stream(integerArray);
+    }
+
+    public static String[] convertToStringArray(Integer[] input) {
+        return Arrays.stream(input)
+          .map(Object::toString)
+          .toArray(String[]::new);
+    }
+
+    public static String[] convertToStringArray(int[] input) {
+        return Arrays.stream(input)
+          .mapToObj(Integer::toString)
+          .toArray(String[]::new);
+    }
+
+    public static String[] convertToStringArrayWithBoxing(int[] input) {
+        return Arrays.stream(input)
+          .boxed()
+          .map(Object::toString)
+          .toArray(String[]::new);
+    }
+
+    public static String convertToString(int[] input){
+        return Arrays.stream(input)
+          .mapToObj(Integer::toString)
+          .collect(Collectors.joining(", "));
+    }
+
+}
diff --git a/core-java-modules/core-java-streams-4/src/test/java/com/baeldung/streams/intarraytostrings/IntArrayToStringUnitTest.java b/core-java-modules/core-java-streams-4/src/test/java/com/baeldung/streams/intarraytostrings/IntArrayToStringUnitTest.java
new file mode 100644
index 0000000000..3f6fb0be8e
--- /dev/null
+++ b/core-java-modules/core-java-streams-4/src/test/java/com/baeldung/streams/intarraytostrings/IntArrayToStringUnitTest.java
@@ -0,0 +1,52 @@
+package com.baeldung.streams.intarraytostrings;
+
+import static com.baeldung.streams.intarraytostrings.ArrayConversionUtils.convertToString;
+import static com.baeldung.streams.intarraytostrings.ArrayConversionUtils.convertToStringArray;
+import static com.baeldung.streams.intarraytostrings.ArrayConversionUtils.convertToStringArrayWithBoxing;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class IntArrayToStringUnitTest {
+
+    @Test
+    public void whenConvertingIntegers_thenHandleStreamOfIntegers() {
+        Integer[] integerNumbers = { 1, 2, 3, 4, 5 };
+        String[] expectedOutput = { "1", "2", "3", "4", "5" };
+
+        String[] strings = convertToStringArray(integerNumbers);
+
+        Assert.assertArrayEquals(expectedOutput, strings);
+    }
+
+    @Test
+    public void whenConvertingInts_thenHandleIntStream() {
+        int[] intNumbers = { 1, 2, 3, 4, 5 };
+        String[] expectedOutput = { "1", "2", "3", "4", "5" };
+
+        String[] strings = convertToStringArray(intNumbers);
+
+        Assert.assertArrayEquals(expectedOutput, strings);
+    }
+
+    @Test
+    public void givenAnIntArray_whenBoxingToInteger_thenHandleStreamOfIntegers() {
+        int[] intNumbers = { 1, 2, 3, 4, 5 };
+        String[] expectedOutput = { "1", "2", "3", "4", "5" };
+
+        String[] strings = convertToStringArrayWithBoxing(intNumbers);
+
+        Assert.assertArrayEquals(expectedOutput, strings);
+    }
+
+    @Test
+    public void givenAnIntArray_whenUsingCollectorsJoining_thenReturnCommaSeparatedString(){
+        int[] intNumbers = { 1, 2, 3, 4, 5 };
+        String expectedOutput = "1, 2, 3, 4, 5";
+
+        String string = convertToString(intNumbers);
+
+        Assert.assertEquals(expectedOutput, string);
+    }
+
+}