自定义Exception

本文改编自http://blog.csdn.net/stellaah/article/details/6738424

[总结]

1.自定义异常:
　　class 异常类名 extends Exception { 
        public 异常类名(String msg) { 
            super(msg); 
        }
    }
2.标识可能抛出的异常:
　　throws 异常类名1,异常类名2
3.捕获异常: 
    try{} catch(异常类名 y){} catch(异常类名 y){}
4.方法解释:
    getMessage()         //输出异常的信息
    printStackTrace()    //输出导致异常更为详细的信息

[代码]

// 自定义异常
class ZeroException extends Exception {
    public ZeroException(String msg) {
        super(msg);
    }
}

class NegtiveException extends Exception {
    public NegtiveException(String msg) {
        super(msg);
    }
}
// 自定义异常 End



class Calculate {
    public int shang(int x, int y) throws ZeroException,NegtiveException {
        if (y < 0) {
            throw new NegtiveException("您输入的是" + y + ",规定除数不能为负数!");// 抛出异常
        }
        if (y == 0) {
            throw new ZeroException("您输入的是" + y + ",除数不能为0!");
        }

        int m = x / y;
        return m;
    }
}

// main
public class AppTest {
    public static void main(String[] args) {
        Calculate calculate = new Calculate();
        // 捕获异常
        try {
            System.out.println("商=" + calculate.shang(1, -3));
        } catch (ZeroException e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        } catch (NegtiveException e) {
            System.out.println(e.getMessage());
        }
    }
}