定义三个整数变量a,b,c 判断能否构成一个三角形
如果不能请抛出一个自定义异常

public class Triangle {
    public static void main(String[] args) {
        try {
            isTriangle();
        } catch (TriangelException e) {
            System.out.println(e.getMessage());
        }
    }

    public static void  isTriangle() throws TriangelException {
        //输入三条边的长度
        System.out.println("输入三边长度：");
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = scanner.nextInt();
        //判断是否构成三角形
        if((a+b)>c && (a+c)>b && (b+c)>a){
            System.out.println("构成三角形");
        }else {
            throw new TriangelException("无法构成三角形");
        }
    }
}


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