exception7.java

课本异常处理实例。各种异常处理

//计算n!
public class Exception7
{
	public static double multi(int n)
	{
		if (n < 0)
			throw new IllegalArgumentException("输入了负数异常");
		double s = 1;
		for (int i=1; i<=n; i++) 
			s = s *i;
		return s;
	}
	public static void main(String args[])
	{
		try
		{
			int n = Integer.parseInt(args[0]);
			System.out.println( n + "!=" + multi(n));
		}
		catch (ArrayIndexOutOfBoundsException e)
		{	System.out.println("应该输入一个整数");	}
		catch (NumberFormatException e2)
		{	System.out.println("应该输入一个数");	}
		catch (IllegalArgumentException e3)
		{	System.out.println("出现的异常为: "+e3.toString());	} 
		finally
		{	System.out.println("计算阶乘结束");}
	}
}