refactor method to check if a password has been pwned

src/main/java/PasswordValidator.java

@@ -15,6 +15,7 @@ public class PasswordValidator {
     private final Pattern uppercasePattern = Pattern.compile("^(?=.*[A-Z]).+$");
     private final Pattern lowercasePattern = Pattern.compile("^(?=.*[a-z]).+$");
     private final Pattern digitPattern = Pattern.compile("^(?=.*\\d).+$");
+    private static final String pwnedPasswordsApiUrl = "https://api.pwnedpasswords.com/range/";
 
     public boolean validate(String password) {
         if (password.length() < minLength) {
@@ -90,13 +91,14 @@ public class PasswordValidator {
     public static boolean isPwned(String password) {
         String sha1 = PasswordValidator.getSHA1Hash(password);
         if (sha1 != null) {
-            String url = "https://api.pwnedpasswords.com/range/" + sha1.substring(0, 5);
+            String url = pwnedPasswordsApiUrl + sha1.substring(0, 5);
             try {
                 String result = HttpApi.sendHttpGETRequest(url);
                 BufferedReader bufReader = new BufferedReader(new StringReader(result));
                 String line = null;
                 while ((line = bufReader.readLine()) != null) {
-                    if (sha1.toUpperCase().endsWith(line.split(":")[0])) {
+                    String[] lineSplit = line.split(":");
+                    if (lineSplit.length > 0 && sha1.toUpperCase().endsWith(lineSplit[0])) {
                         return true;
                     }
                 }

src/test/java/PasswordValidatorTest.java

@@ -58,5 +58,7 @@ class PasswordValidatorTest {
     @Test
     void isPwned() {
         assertTrue(PasswordValidator.isPwned("asdf12"));
+        assertFalse(PasswordValidator.isPwned("=phan0johB4aisae6Mie0jeip9Saejahc0iuvuth7ahv9uoni6o*_.+"));
+        assertFalse(PasswordValidator.isPwned(""));
     }
 }