public class Test{    public static void main(String[] args){        Income[] incomes = new Income[]{                new Salary(15000),                new Gaofei(1000)        };        System.out.println(gettotal(incomes));    }    public static double gettotal(Income... incomes){        double total = 0;        for(Income t: incomes){            total += t.getTax();        }        return total;    }}abstract class Income{    double income;    public Income(double income){        this.income = income;    }    public abstract double getTax();}class Salary extends Income{    public Salary(double income){        super(income);    }    @Override    public double getTax(){        if(income <= 5000){            return 0;        }        return (income-5000)*0.2;    }}class Gaofei extends Income{    public Gaofei(double income){        super(income);    }    public double getTax(){        return income*0.1;    }}