waterElectricityService/Test.java

package testExport;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

public class Test {

    public static void main(String[] args) {
        List<String> dateList = new ArrayList<>();
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM");
        for (int i=0;i>-12;i--){
            Calendar calendar = Calendar.getInstance();
            calendar.add(Calendar.MONTH,i);
            dateList.add(simpleDateFormat.format(calendar.getTime()));
        }
        System.out.println(dateList);
    }

}