创建自定义异常

class MyException extends Exception {
	public MyException(){}
	public MyException(String msg){
		super();
	}
}
public class FullConstructors{
	public static void f() throws MyException{
		System.out.println("Throwing MyException from f()");
		throw new MyException();
	}
	public static void g() throws MyException{
		System.out.println("Throwing MyException from g()");
		throw new MyException("Originated in g()");
	}
	public static void main(String[] args){
		try{
			f();
		}catch(MyException e){
			e.printStackTrace(System.out);
		}
		try{
			g();
		}catch(MyException e){
			e.printStackTrace(System.out);
		}
	}
}

两个构造器定义了MyException类型对象的创建方式，对于第二个构造器，使用super关键字明确调用了其基类构造器，他接受一个字符串作为参数。

异常处理程序中，调用了Throwable类声明的printStackTrace()方法。