format of android text strings

Good, I have the following problem: I am making a query to a database, the query brings me a value type String with a format type ###. ###, ## the question I have are the following:

1.- How can I eliminate the commas and points to use that data in a mathematical operation within the app. (taking into account that the number in question may have decimals

2.- How can I get a new TextView after the operation to keep the format that I bring?

All this applied to a textWacther

saldito = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

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


        }

        @Override
        public void afterTextChanged(Editable s) {

            saldo_despues.setText(addNumbers());
            int ncom1, ncom2;
            if(saldoUsrAct.getText().toString() != "" && saldoUsrAct.getText().length() > 0) {
                ncom2 = Integer.parseInt(saldoUsrAct.getText().toString());

            } else {
                ncom2 = 0;
            }
            if(ttmonto.getText().toString() != "" && ttmonto.getText().length() > 0) {
                    ncom1 = Integer.parseInt(ttmonto.getText().toString());
            } else {
                ncom1 = 0;
            }

            if(ncom1 > ncom2){
                saldo_despues.setTextColor(Color.parseColor("#FFE70822"));
            } else {
                saldo_despues.setTextColor(Color.parseColor("#000000"));
            }

        }
    };
    ttmonto.addTextChangedListener(saldito);



}



private String addNumbers() {
    int number1;
    int number2;
    if(saldoUsrAct.getText().toString() != "" && saldoUsrAct.getText().length() > 0) {
        number1 = Integer.parseInt(saldoUsrAct.getText().toString());
    } else {
        number1 = 0;
    }
    if(ttmonto.getText().toString() != "" && ttmonto.getText().length() > 0) {
        number2 = Integer.parseInt(ttmonto.getText().toString());
    } else {
        number2 = 0;
    }

    return Integer.toString(number1 - number2);
}

} 

This code works for me because I have not assigned the value to one of the textview, but at the moment it takes the variable that I bring from the database, it generates the error, as I can do to work with the chains that I bring.

Here I have another way that does not work either:

public void afterTextChanged(Editable s) {
            String convertedString = new DecimalFormat("##.###.###,##").format(Double.parseDouble(addNumbers()));
            saldo_despues.setText(convertedString);
            double ncom1, ncom2;
            if(saldoUsrAct.getText().toString() != "" && saldoUsrAct.getText().length() > 0) {
                ncom2 = Double.parseDouble(saldoUsrAct.getText().toString());

            } else {
                ncom2 = 0;
            }
            if(ttmonto.getText().toString() != "" && ttmonto.getText().length() > 0) {
                    ncom1 = Double.parseDouble(ttmonto.getText().toString());
            } else {
                ncom1 = 0;
            }

            if(ncom1 > ncom2){
                saldo_despues.setTextColor(Color.parseColor("#FFE70822"));
            } else {
                saldo_despues.setTextColor(Color.parseColor("#000000"));
            }

        }
    };
    ttmonto.addTextChangedListener(saldito);



}



private String addNumbers() {
    double number1;
    double number2;
    if(saldoUsrAct.getText().toString() != "" && saldoUsrAct.getText().length() > 0) {
        number1 = Double.parseDouble(saldoUsrAct.getText().toString());
    } else {
        number1 = 0;
    }
    if(ttmonto.getText().toString() != "" && ttmonto.getText().length() > 0) {
        number2 = Double.parseDouble(ttmonto.getText().toString());
    } else {
        number2 = 0;
    }

    return Double.toString(number1 - number2);
}

Ok, I want to format a TextView, since I'm already figuring out how to bring from the server, a string that does not need to be modified in any way (a bit rudimentary but can work), what I need is to know how format the textview so that it shows me the formatted data the way I want.

Thank you in advance