Java异常来自哪里？(Where do Java exceptions came from?)

 到目前为止，我认为必须由构造函数在某处创建每个Java异常，因为我可以自己创建自定义异常： 
 
throw new Exception();
 
 但现在看来我必须处理来自JavaMail的一些异常 - MessagingException 。 它来自Store.close方法（继承自Service类）。 
 
 我去了那里（我需要检查什么时候抛出这个异常所以我知道什么是错的）我看到这个方法调用了另外两个方法 - 它们都没有抛出异常！ 
 
public synchronized void close() throws MessagingException {
    setConnected(false);
    notifyConnectionListeners(ConnectionEvent.CLOSED);
}
 
 据我所知，这是检查Exception（既不是Error也不是RuntimeException），那么怎么可能不必在close方法命令中使用它？ 在这种方法中也没有创建它。 

Until now, I thought that every Java exception has to be created somewhere by a constructor, as I can create on my own, custom exceptions:
 
throw new Exception();
 
But now it seems that I have to handle some exception from JavaMail - MessagingException. It comes from the method Store.close (inherited from Service class).
 
I went there (I need to check when this exception is thrown so I know what can be wrong) and I see that this method calls two other methods - none of them throw an exception!
 
public synchronized void close() throws MessagingException {
    setConnected(false);
    notifyConnectionListeners(ConnectionEvent.CLOSED);
}
 
As far as I understand, this is checked Exception (neither Error nor RuntimeException), so how is it possible that it doesn't have to be declared in any of used by close method commands? It is also not created here, in this method.

原文：https://stackoverflow.com/questions/43998873