how to add character with double so it works like methamatics java

i have two arraylists one is double name = numbers which store user input(double) and second is character name = operators which store input(+,-,*,/) entered by the user. the code is below. i want that when user enter a values the code should get the numbers value and do the operation entered in operators. please check the code below and tell me how to do it.

List<Double> numbers = new ArrayList<>();
List<Character> operators = new ArrayList<>();
........................

/* after getting input from user the code is now working as below.*/

void result() {
    et1.setText("");
    for (int i = 0; i < handler; i++) {
        double total2 = operators.get(i) + numbers.get(i);
        total3 += total2;
        et1.setText(Double.toString(total3));
    }

}
/*all values are just being add with eachother which are entered by the user.
help me how to solve this issue. */

Basically its not possible with the way you are doing like:

double total2= operators.get(i)+numbers.get(i);

You would need a switch with operators like:

switch (operators.get(i)) {
    case '+':
         //do add
         break;
    case '-':
         //subtract
         break
    blah blah...
}