如何在Java中的HashMap中检查密钥的值是否正确

Question

I'm writing a simple GUI program where I have to input login and password for user and then check if he is in database (my Hashmap). That's where i have problem. I checked if login is correct by containsKey and checked for password by containsValue. The problem is, that if in example I have 2 users:

login: user1 password: example
login: user2 password: programing

If I put login as user1 in my JTextField and password "programing", the program says, that it's correct.

That's where I have a problem. How to check the password for exact login, which is key?

Would be very thankful for any clues or solutions :)

Answer 1

You can use a check like this:

 if(userEnteredPassword.equals(hashMap.get(userEnteredUsername))){
     // Correct credentials.
     .....
 }

It's important to use userEnteredPassword.equals.... instead of hashMap.get(userEnteredUsername).equals... because you'll get a null pointer exception if there is no map entry for userEnteredUsername