I have two methods:

public Person signIn(String login, String password) {
        GenericTuple<String,String> pair = new GenericTuple<>(login,password);
        Person p = dataSource.getMapUsers().get(pair);
        return dataSource.getMapUsers().get(pair);
    }
    public void registration(Person person) {
        GenericTuple<String,String> pair = new GenericTuple<>(person.getLogin(),person.getPassword());
        dataSource.getMapUsers().put(pair,person);
    }

The code for GenericTuple is:

 public final class GenericTuple<F, S> {
    private final F first;
    private final S second;

    public GenericTuple(F first, S second) {
        this.first = first;
        this.second = second;
    }

    public F getFirst() {
        return first;
    }

    public S getSecond() {
        return second;
    }

    @Override
    public String toString() {
        return "Tuple(first="   first   ", second="   second   ")";
    }

}

After adding new element to my map(method "registration") i see in mapUsers new key and value.But in method signIn after registration the returning value of .get(pair) is null.Why this?

CodePudding user response：

Instead of using GenericTuple as the map's key, you should use login id as the key.

I don't think it is correct if you use GenericTuple as key. What if 2 Generic Tuples have the same login id, but different password (change password scenario perhaps), do you consider them equal and have the same hashcode?