学步园

方法声明抛出Exception，实际抛出为子类Exception，具体catch时会被子类Exception块捕获处理。

public class TestException extends Exception{

    public void throwException() throws Exception {
        TestException exception = new TestException();
        throw exception;
    }

    public static void main(String[] args) {
        TestException t = new TestException();
        try {
            t.throwException();
        } catch (TestException e) {
            System.out.println("a");   //会走这里
        } catch (Exception e) {
            System.out.println("b");
        }
    }

}