Java checking last element of LinkedList that is part of a TreeMap

Question

I have a Java program which reads usernames and password histories from a text file and stores the info in a TreeMap. The user is then allowed to change passwords by selecting the username and then inputting their current password. The user info is initialized as:

TreeMap<String,LinkedList<String>> userInfo = new TreeMap<String,LinkedList<String>>();

The LinkedList is filled in this while loop:

while (filescan.hasNext()) {
    String toParse = filescan.nextLine();
    String[] parsed = toParse.split(" ");
    username = parsed[0];
    LinkedList<String> oldpws = new LinkedList<String>();
    for (int i = 1; i < parsed.length; i++) {
        oldpws.add(parsed[i]);
    }
    userInfo.put(username, oldpws);
}

The problem I'm running into is later on, comparing the password entered by the user with the last element of the LinkedList related to the given key. I can't use contains(currPW) because that can return true for an invalid password.

if (/*last index of key's LinkedList*/.equals(currPW) {
   //...
}

How can I access specifically the last index of the LinkedList as part of the TreeMap?

Answer 1

Some of the answers already point to the currect answer. But lets assume you have two input Strings with the username and password of a user you want to validate:

if (userInfo.contains(username)){
  if(userInfo.get(username).getLast().equals(password){
   return true;
  } else {
   //Bad password
   return false;
  }
}
//Unknown user
return false;