Implemented the "getList" method of the interface "IRetrieveList", this is yet to be tested.

Author: Madhavan7

src/main/java/IRetrieveList.java

@@ -0,0 +1,5 @@
+import java.util.List;
+
+public interface IRetrieveList {
+    List<User> getList();
+}

src/main/java/UserDatabase.java

@@ -1,6 +1,7 @@
 import java.io.*;
-import java.util.Scanner;
-public class UserDatabase implements UserExists, UserRetriever, UserCreator{
+import java.util.ArrayList;
+import java.util.List;
+public class UserDatabase implements UserExists, UserRetriever, UserCreator, IRetrieveList{
     File accounts;
     public UserDatabase(File accounts){
         this.accounts = accounts;
@@ -64,4 +65,20 @@ public User getUser(String username) {
         }
         return user;
     }
+    //Returns an ArrayList with the users that is extracted from the file, so that other objects can use this list.
+    @Override
+    public List<User> getList() {
+        List<User> users = new ArrayList<>();
+        try(FileInputStream fileIn = new FileInputStream(accounts);
+            ObjectInputStream in = new ObjectInputStream(fileIn)){
+            User user = (User) in.readObject();
+            while(user != null){
+                users.add(user);
+                user = (User)in.readObject();
+            }
+        }catch(Exception e){
+            e.printStackTrace();
+        }
+        return users;
+    }
 }