From 4391c0ee342fce1e6c1620dee128d9c5afa98a93 Mon Sep 17 00:00:00 2001
From: Richard Schmidt <richard.schmidt@informatik.hs-fulda>
Date: Fri, 9 Feb 2024 21:57:16 +0100
Subject: [PATCH] refactoring: isUsernameAvailable in SignUpGUI

---
 src/main/java/SignUpGUI.java | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/src/main/java/SignUpGUI.java b/src/main/java/SignUpGUI.java
index 70aa72f..faa360d 100644
--- a/src/main/java/SignUpGUI.java
+++ b/src/main/java/SignUpGUI.java
@@ -149,14 +149,7 @@ public class SignUpGUI extends JFrame implements ActionListener {
     // Function to check if the input username doesn't already exist in the JSON file
     private boolean isUsernameAvailable(String filename, String username) {
         List<CreateUser> userList = CreateUser.readUserListFromJsonFile(filename);
-        if (userList != null) {
-            for (CreateUser user : userList) {
-                if (user.getUserName().equals(username)) {
-                    return false; 
-                }
-            }
-        }
-        return true; 
+        return userList == null || userList.stream().noneMatch(user -> user.getUserName().equals(username));
     }
 
     public static void main(String[] args) {