This commit is related to BAEL-7341 (#15410)

This commit aims to add a test class "StringToCharListUnitTest" that suggests several ways to convert a string into a list of charachters.

core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringtocharlist/StringToCharListUnitTest.java

@@ -0,0 +1,62 @@
+package com.baeldung.stringtocharlist;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import com.google.common.collect.Lists;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class StringToCharListUnitTest {
+    public String inputString = "Convert a String to a List of Characters in Java";
+
+    @Test
+    public void givenString_whenUsingToCharArray_thenConvertToCharList() {
+        char[] charArray = inputString.toCharArray();
+
+        List<Character> charList = new ArrayList<>();
+        for (char c : charArray) {
+            charList.add(c);
+        }
+
+        assertEquals(inputString.length(), charList.size());
+    }
+
+    @Test
+    public void givenString_whenUsingMapToObj_thenConvertToCharList() {
+        List<Character> charList = inputString.chars()
+                .mapToObj(c -> (char) c)
+                .toList();
+
+        assertEquals(inputString.length(), charList.size());
+    }
+
+    @Test
+    public void givenString_whenUsingSplit_thenConvertToStringList() {
+        String[] charArray = inputString.split("");
+
+        List<String> charList = Arrays.asList(charArray);
+
+        assertEquals(inputString.length(), charList.size());
+    }
+
+    @Test
+    public void givenString_whenUsingGuavaLists_thenConvertToCharList() {
+        List<Character> charList = Lists.charactersOf(inputString);
+
+        assertEquals(inputString.length(), charList.size());
+    }
+
+    @Test
+    public void givenString_whenUsingCodePoints_thenConvertToCharList() {
+        List<Character> charList = inputString.codePoints()
+                .mapToObj(c -> (char) c)
+                .toList();
+
+        assertEquals(inputString.length(), charList.size());
+    }
+}