implement generating passwords with uppercase letters

src/main/java/PasswordGenerator.java

@@ -3,6 +3,7 @@ import java.security.SecureRandom;
 public class PasswordGenerator {
 
     final String lowercaseCharacters = "abcdefghjkmnpqrstuvwxyz";
+    final String uppercaseCharacters = "ABCDEFGHJKMNPQRSTUVWXYZ";
 
     int length = 12;
 
@@ -17,9 +18,13 @@ public class PasswordGenerator {
     public String generateRandomPassword() {
         StringBuilder generatedPassword = new StringBuilder();
         SecureRandom rand = new SecureRandom();
+        String characterPool = "";
+
+        characterPool += lowercaseCharacters;
+        characterPool += uppercaseCharacters;
 
         for (int generatorPosition = 0; generatorPosition < getLength(); generatorPosition++) {
-            generatedPassword.append(lowercaseCharacters.charAt(rand.nextInt(lowercaseCharacters.length())));
+            generatedPassword.append(characterPool.charAt(rand.nextInt(characterPool.length())));
         }
         return generatedPassword.toString();
     }

src/test/java/PasswordGeneratorTest.java

@@ -28,4 +28,9 @@ class PasswordGeneratorTest {
     void testPasswordLowercaseRequirement() {
         assertTrue(Pattern.compile("^(?=.*[a-z]).+$").matcher(passwordGenerator.generateRandomPassword()).matches());
     }
+
+    @Test
+    void testPasswordUppercaseRequirement() {
+        assertTrue(Pattern.compile("^(?=.*[A-Z]).+$").matcher(passwordGenerator.generateRandomPassword()).matches());
+    }
 }