try7.java

Java Classic Examples是我买的两本书：《JAVA经典实例》和《java入门经典源代码》里边附送光盘里带的源码

class OverflowException extends Exception      //自定义异常类
{
    public void printMsg()
    {
        System.out.println("exception: "+this.getMessage());
        this.printStackTrace();
        System.exit(0);
    }
}
public class Try7
{
    public void calc(byte k) throws OverflowException //抛出异常
    {
        byte  y=1,i=1;
        System.out.print(k+"!=");
        for (i=1;i<=k;i++)
        {
            if(y>Byte.MAX_VALUE/i)
                throw new OverflowException();
            else
                y = (byte)(y * i);
        }
        System.out.println(y);
    }
    public void run(byte k)                     //捕获并处理异常
    {
        try
        {
            calc(k);
        }
        catch(OverflowException e)
        {
            e.printMsg();
        }
    }
    public static void main (String args[])
    {
        Try7 a = new Try7();
        for (byte i=1;i<10;i++)
            a.run(i);
    }
}