JNotify and File Reader conflicting each other

I implemented JNotify to determine when a new file arrives in a particular directory, and, when a file arrives, to send the filename over to another function, as follows:

    public class FileDetector {
            MessageProcessor mp;
            class Listener implements JNotifyListener {
                    public void fileCreated(int wd, String rootPath, String name) {
                            print("created " + rootPath + " : " + name);
                            mp.processMessage(rootPath + "\\" + name);
                    }
            }
    }

The function mp.processMessage tries to open the file, but I keep getting an e开发者_C百科rror that the file is in use by another process. However, as the file has just been created, the only other process which might be using it is JNotify.

I put a couple of print statements, and it appears that the function mp.processMessage is being called before the listener's print function. Does anyone have a suggestion for how I might resolve this, beyond putting the entire message processing inside the listener class?

@Eile What I think is As soon as one process is copying the file, you are trying to read it, 100 ms delay will complete the copy first n then you can read the file easily.

Here's what I've done so far - I added into mp.processMessage() a 100 millisecond delay before trying to open the file, and have had no issues with it. However, I am still puzzled as to why that would be necessary, and whether or not there is a better solution to this issue.

I have tried this and have found that an arbitrary delay didn't work well for me. What I did was create a DelayQueue. I added each observed new file to the queue with a 100ms delay. When the delay expired I checked if the file was readable/writable. If is was, I popped it from the queue. If not, I readded it to the queue with another 100ms delay. To check if it was readable/writable I attempt to open a FileInputStream to the file. If no exception, I close the stream and pop the file.

I am hoping that nio.2 (jsr 203) does not have this same issue. If you can use Java 7 you might want to give it a try.