自定義Exception

本文改編自http://blog.csdn.net/stellaah/article/details/6738424

[總結]

1.自定義異常:
　　class 異常類名 extends Exception { 
        public 異常類名(String msg) { 
            super(msg); 
        }
    }
2.標識可能拋出的異常:
　　throws 異常類名1,異常類名2
3.捕獲異常: 
    try{} catch(異常類名 y){} catch(異常類名 y){}
4.方法解釋:
    getMessage()         //輸出異常的信息
    printStackTrace()    //輸出導致異常更為詳細的信息

[代碼]

// 自定義異常
class ZeroException extends Exception {
    public ZeroException(String msg) {
        super(msg);
    }
}

class NegtiveException extends Exception {
    public NegtiveException(String msg) {
        super(msg);
    }
}
// 自定義異常 End



class Calculate {
    public int shang(int x, int y) throws ZeroException,NegtiveException {
        if (y < 0) {
            throw new NegtiveException("您輸入的是" + y + ",規定除數不能為負數!");// 拋出異常
        }
        if (y == 0) {
            throw new ZeroException("您輸入的是" + y + ",除數不能為0!");
        }

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

// main
public class AppTest {
    public static void main(String[] args) {
        Calculate calculate = new Calculate();
        // 捕獲異常
        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());
        }
    }
}