作业-异常处理2

建立exception包，建立Bank类，类中有变量double  balance表示存款,Bank类的构造方法能增加存款，Bank类中有取款的发方法withDrawal(double dAmount),当取款的数额大于存款时,抛出InsufficientFundsException,取款数额为负数，抛出NagativeFundsException,如new Bank(100),表示存入银行100元，当用方法withdrawal(150)，withdrawal(-15)时会抛出自定义异常。

package Bank;

public class Bank {
    private static double balance;
    Bank(){

    };
    Bank(double balance){
        this.balance=balance;
    }
    public static void withDrawal(double dAmount) throws InsufficientFundsException,NagativeFundsException{
        if(dAmount>balance){
            throw new InsufficientFundsException();
        }
        if(dAmount<0){
            throw new NagativeFundsException();
        }
    }
    public static void main(String[] args){
        Bank b=new Bank(100);
        System.out.println("我有"+balance+"元存款！");
        try{
            withDrawal(150);
        }catch(InsufficientFundsException | NagativeFundsException e){
            e.printStackTrace();
        }
        try{
            withDrawal(-15);
        }catch(NagativeFundsException |InsufficientFundsException e){
            e.printStackTrace();
        }
    }
}

package Bank;

public class InsufficientFundsException extends Exception {
    public String getMessage(){
        return "您的余额不足！";
    }
}

package Bank;

public class NagativeFundsException extends Exception{
    public String getMessage(){
        return "取款金额不能为负数！";
    }
}