How do I unregister a directory from Java watchservice?

问题

I registered a folder to my watchService:

path.register(watchService, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);

Later on, I want to cancel this registration. I know that I somehow need to tell the watchService which WatchKey I want to cancel. What's the correct function to accomplish this?

回答1:

You have the information in the Watchable interface javadoc that provides the method to register a Watchable object (such as a Path instance)

---

public interface Watchable

This interface defines the register method to register the object with a WatchService returning a WatchKey to represent the registration. An object may be registered with more than one watch service. Registration with a watch service is cancelled by invoking the key's cancel method.

---

So you have just to do :

WatchKey watchKey = path.register(watchService, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
...
watchKey.cancel();

回答2:

The register method returns the WatchKey, as described in the documentation, which has a cancel() method.

来源：https://stackoverflow.com/questions/43950919/how-do-i-unregister-a-directory-from-java-watchservice