How to make calling a method dynamic with a Switch Case- Java

Question

I want to call a method. Depending on a argument a certain method will be called. Currently I am trying to achieve this using a Switch Case, but I cant get it to work.

Code:

String getoption = null;
switch (rateIndex){

case 3:
    getoption = "bar.getOneMonth();"
case 4:
    getoption = "bar.getTwoMonth();"
case 5:
    getoption = "bar.getThreeMonth();"

}

Big Decimal qMidRate = null;

for(MonthlyRates bar: results){
    qMidRate = getoption;  
    //more logic 
}

I am trying to get a Big Decimal value from the get methods, is there any way of doing this? any help would be appreciated.

Answer 1

If all those methods are returning strings, simply ditch the double quotes:

case 3:
    getoption = bar.getOneMonth();
    break;
case 4:
    getoption = bar.getTwoMonth();
    break;
case 5:
    getoption = bar.getThreeMonth();
    break;

Answer 2

You can do this with method references/lambdas if you're using java 8. Something like:

    // I have no idea what 'getOneMonth', etc. are returning or have as parameters...
    // This assumes they take a Long, and return a String, 'cause I don't know.
    Function<Long, String> choice = null;
    switch (rateIndex) {
        case 3:
            choice = bar::getOneMonth;
            break;
        case 4:
            choice = bar::getTwoMonths;
            break;
        // ...
        default:
            throw new HissyFit();
    }

    for (final MonthlyRates rates : bar.getMonthlyRates()) {
        final String methodCallResult = choice.apply(rates.getSomeLong());
    }