CODEWITHSUNDEEP
javaioinputstreamioexceptionfileinputstream
lisak
lisak

Reputation: 21971

How to deal with corrupted files that were created but IOException occured?

Could you please suggest how to deal with these situations ? I understand that in the second example, it is very rare that it would happen on unix, is it ? If access rights are alright. Also the file wouldn't be even created. I don't understand why the IOException is there, either it is created or not, why do we have to bother with IOException ?

But in the first example, there will be a corrupted zombie file. Now if you tell the user to upload it again, the same thing may happen. If you can't do that, and the inputstream has no marker. You loose your data ? I really don't like how this is done in Java, I hope the new IO in Java 7 is better

Is it usual to delete it 

public void inputStreamToFile(InputStream in, File file) throws SystemException {

    OutputStream out;
    try {
        out = new FileOutputStream(file);
    } catch (FileNotFoundException e) {
        throw new SystemException("Temporary file created : " + file.getAbsolutePath() + " but not found to be populated", e);
    }

    boolean fileCorrupted = false;
    int read = 0;
    byte[] bytes = new byte[1024];

    try {
        while ((read = in.read(bytes)) != -1) {
            out.write(bytes, 0, read);
        }
    } catch (IOException e) {
        fileCorrupted = true;
        logger.fatal("IO went wrong for file : " + file.getAbsolutePath(), e);
    } finally {
        IOUtils.closeQuietly(in);
        IOUtils.closeQuietly(out);

                    if(fileCorrupted) {
        ???
                    }
    }
}


public File createTempFile(String fileId, String ext, String root) throws SystemException {

    String fileName = fileId + "." + ext;

    File dir = new File(root);

    if (!dir.exists()) {
        if (!dir.mkdirs())
            throw new SystemException("Directory " + dir.getAbsolutePath() + " already exists most probably");
    }

    File file = new File(dir, fileName);

    boolean fileCreated = false;
    boolean fileCorrupted = false;
    try {
        fileCreated = file.createNewFile();
    } catch (IOException e) {
        fileCorrupted = true;
        logger.error("Temp file " + file.getAbsolutePath() + " creation fail", e);
    } finally {

        if (fileCreated)
            return file;
        else if (!fileCreated && !fileCorrupted)
            throw new SystemException("File " + file.getAbsolutePath() + " already exists most probably");
        else if (!fileCreated && fileCorrupted) {

        }
    }

}

Upvotes: 0

Views: 4725

Answers (1)

matt b
matt b

Reputation: 139921

I really don't like how this is done in Java, I hope the new IO in Java 7 is better

I'm not sure how Java is different than any other programming language/environment in the way you are using it:

  • a client sends some data to your over the wire
  • as you read it, you write it to a local file

Regardless of the language/tools/environment, it's possible for the connection to be interrupted or lost, for the client to go away, for the disk to die, or for any other error to occur. I/O errors can occur in any and all environments.

What you can do in this situation is highly dependent on the situation and the error that occured. For example, is the data structured in some way where you could ask the user to resume uploading from record 1000, for example? However, there is no single solution that fits all here.

Upvotes: 1

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