This commit is related to BAEL-7254 (#15299)

This commit aims to add a new test class "ByteToCharArrayUnitTest" that validates the conversion process of a Byte array into a Char array.

core-java-modules/core-java-arrays-convert/src/test/java/com/baeldung/array/conversions/ByteToCharArrayUnitTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.array.conversions;
+
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class ByteToCharArrayUnitTest {
+    public static byte[] byteArray = {65, 66, 67, 68};
+    public static char[] expected = {'A', 'B', 'C', 'D'};
+
+    @Test
+    public void givenByteArray_WhenUsingStandardCharsets_thenConvertToCharArray() {
+        char[] charArray = new String(byteArray, StandardCharsets.UTF_8).toCharArray();
+        assertArrayEquals(expected, charArray);
+    }
+
+    @Test
+    public void givenByteArray_WhenUsingSUsingStreams_thenConvertToCharArray() throws IOException {
+        ByteArrayInputStream inputStream = new ByteArrayInputStream(byteArray);
+        InputStreamReader reader = new InputStreamReader(inputStream);
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        int data;
+        while ((data = reader.read()) != -1) {
+            char ch = (char) data;
+            outputStream.write(ch);
+        }
+        char[] charArray = outputStream.toString().toCharArray();
+        assertArrayEquals(expected, charArray);
+    }
+
+    @Test
+    public void givenByteArray_WhenUsingCharBuffer_thenConvertToCharArray() {
+        ByteBuffer byteBuffer = ByteBuffer.wrap(byteArray);
+        CharBuffer charBuffer = StandardCharsets.UTF_8.decode(byteBuffer);
+        char[] charArray = new char[charBuffer.remaining()];
+        charBuffer.get(charArray);
+        assertArrayEquals(expected, charArray);
+    }
+}