java 异常练习题1

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 exception;

public class Bank {
    double balance;
    public Bank(double balance)
    {
        
    }
    public void withDrawal(double dAmount)  throws Exception
    {
        if(dAmount>balance)
        {
            
            throw new InsufficientFundsException();
            
            
        }
        if(dAmount<0)
        {
            throw new NagativeFundsException();
        }
        
        balance =balance-dAmount;
        
        
    }

}

package exception;

public class InsufficientFundsException extends Exception {

    @Override
    public String getMessage() {
        // TODO 自动生成的方法存根
        return "余额不足！";
    }
    

}

package exception;

public class NagativeFundsException extends Exception {

    @Override
    public String getMessage() {
        // TODO 自动生成的方法存根
        return "取款数不能为负数";
    }
    

}

package exception;

public class Test1 {

    public static void main(String[] args) {
        // TODO 自动生成的方法存根

        Bank b=new Bank(100);
        try{ 
            b.withDrawal(150);
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
        try{
            b.withDrawal(-15);
        }
        catch(Exception e)
        {
            System.out.println(e.getMessage()) ;
        }
    }

}