How to make KeyDown and KeyUp on android device?

I have a question.

Im making Keystroke dynamics app on android devices.

For now, i make an activity with measure string and EditText. I want to catch KeyDown and KeyUp events on software keyboard.

My question is, what is the best way to catch KeyUp and KeyDown on Android with Java? If EditText is a good choose? If it have methods to catch any keypresses?

EDIT

I want to detect keys from string above and measure time of pressing it, (start measure on KeyDown and stop on KeyUp for example). If its possible, i want to block other keys that is not mentioned in my test string (its 9RJhl6aH0n, like in my screen)

EDIT2

What i achive so far is something like this, but my app crashes on default, when i coded line: measureText.setText(""). It works pretty ok, but still it wont trigger on KeyDown (or KeyPress). These methods runs only on KeyUp, when user just typed letter. Order is very important!

measureText.addTextChangedListener(new TextWatcher(){
        @Override
        public void afterTextChanged(Editable arg0) {
            switch(measureText.getText().toString()){
                case "9":
                    break;
                case "9R":
                    break;
                case "9RJ":
                    break;
                case "9RJh":
                    break;
                case "9RJhl":
                    break;
                case "9RJhl6":
                    break;
                case "9RJhl6a":
                    break;
                case "9RJhl6a0":
                    break;
                case "9RJhl6a0n":
                    break;
                default:
                    measureText.getText().clear();
                    break;

            }
            return;
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            // TODO Auto-generated method stub
            return;
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            return;
        }
    });

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