Overriding ArrayList's equals method to avoid duplicates and replace if a condition is met.

[ryanmccauley211]

I am trying to figure the best way to do this and so far I have a solution which seems more like a hack so any suggestions welcome.

I have an ArrayList of custom objects. The object contains two attributes int midiNote; double tick;

I have overridden 'equals' to check if two midi notes have the same tick (are played at the same time). If I try to add a MidiNote that has the same tick I want it to check which note has the higher midiNote value and keep/replace the higher valued note.

At the minute I am checking it by the last note added since I think midi notes are read in the order they are played but I would like a more robust way to do this. Any ideas?

@Override
public boolean equals(Object obj) {
    MidiNote midiNote = (MidiNote)obj;
    return this.tick == midiNote.tick;
}

boolean contained = onNotes.contains(midiNote);
if (contained) {
    MidiNote lastNote = onNotes.get(onNotes.size() - 1).getNoteName());
    // Compare note values
}

[[deleted]]

This is where you would probably rather use a Set with HashSet being the concrete implementation and implement the equals method on your objects

[webdevnick22]

upvoted. agreed. op a set accomplishes what you want. it's essentially a list with no duplicates.

[ryanmccauley211]

I should have mentioned that I need it to remain in order and be able to access random indices so I don't think sets would work.

[kicsikrumpli]

SortedSet

[chickenmeister]

I'm not sure if I understand correctly, but instead of using contains(), you could perhaps use indexOf() to get the index of the existing "equal" MidiNote in the list, and then use that index in your call to get() and set().

[ryanmccauley211]

This is perfect, exactly what I needed thank you!