CODEWITHSUNDEEP
javafileeofexception
sirdan
sirdan

Reputation: 1028

End of File Exception on ObjectInputStream.readObject

My application streams twitter data and writes them to files.

while(true){
        Status status = queue.poll();

        if (status == null) {
            Thread.sleep(100);
        }

        if(status!=null){
            list.add(status);
        }

        if(list.size()==10){
            FileOutputStream fos = null;
            ObjectOutputStream out = null;
            try {
                String uuid = UUID.randomUUID().toString();
                String filename = "C:/path/"+topic+"-"+uuid+".ser";
                fos = new FileOutputStream(filename);
                out = new ObjectOutputStream(fos);
                out.writeObject(list);
                tweetsDownloaded += list.size();
                if(tweetsDownloaded % 100==0)
                    System.out.println(tweetsDownloaded+" tweets downloaded");
            //  System.out.println("File: "+filename+" written.");
                out.close();
            } catch (IOException e) {

                e.printStackTrace();
            }

            list.clear();
    }

I have this code which gets data from files. 

while(true){
    File[] files = folder.listFiles();

    if(files != null){
        Arrays.sort(//sorting...);

        //Here we manage each single file, from data-load until the deletion
        for(int i = 0; i<files.length; i++){
            loadTweets(files[i].getAbsolutePath());
            //TODO manageStatuses
            files[i].delete();
            statusList.clear();
        }

    }

}

The method loadTweets() does the following operations:

private static void loadTweets(String filename) {

    FileInputStream fis = null;
    ObjectInputStream in = null;
    try{
        fis = new FileInputStream(filename);
        in = new ObjectInputStream(fis);
        statusList = (List<Status>) in.readObject();
        in.close();
    }
    catch(IOException | ClassNotFoundException ex){
        ex.printStackTrace();
    }


}

Unfortunately, I don't know why sometimes it throws a

EOFException

when running this line

statusList = (List<Status>) in.readObject();

Anybody knows how I can solve this? Thank you.

Upvotes: 0

Views: 381

Answers (2)

sirdan
sirdan

Reputation: 1028

Found out what was necessary to solve this. Thanks to @VGR's comment, I thought to pause the executing thread for 0.2 seconds if the file has been created less than a second ago.

if(System.currentTimeMillis()-files[i].lastModified()<1000){
        Thread.sleep(200);

This prevents the exception and the application works now fine.

Upvotes: 1

Pedro Cavaleiro
Pedro Cavaleiro

Reputation: 922

I've seen that you're passing the file correctly with the getAbsolutePath() based on a previous question of yours

From what I've read that can be a couple of things, one of them the file being null.

Explaining this idea, you might have written the file but something caused the file to have nothing inside, this might cause an EOFException. The file in fact exists it's just empty

EDIT

Try to enclose the code in while(in.available() > 0)

It would look like this

private static void loadTweets(String filename) {

    FileInputStream fis = null;
    ObjectInputStream in = null;
    try{
        fis = new FileInputStream(filename);
        in = new ObjectInputStream(fis);
        while(in.available() > 0) {
            statusList = (List<Status>) in.readObject();
        }
        in.close();
    }
    catch(IOException | ClassNotFoundException ex){
        ex.printStackTrace();
    }
}

Upvotes: 2

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