readUTF works once, then throws EOFException

Question

I'm writing to a RandomAccessFile like that: (in a LinkedList's subclass)

file.setLength(0);
for (Person person : this)
    file.writeUTF(person.getBlob());

Person.getBlob() returns a string of constant length, containing only basic alphanumeric characters, spaces and CRs (only one-byte characters). At this place the file contains exactly 100 records. (confirmed with a hex editor)

Then I try to read that file:

int counter = 0;

while (true) {
    try {
        add(Person.fromBlob(file.readUTF()));
    } catch (EOFException e) {
        System.out.println(counter + " records read from file.");
        break;
    } catch (Exception exception) {
        throw new DBException(exception);
    }

    counter++;
}

I always end up with one record read correctly and an EOFException. What's wrong with this code?

Program creates that file if it doesn't exist and exits, then reads it when started again. So yes, the file is being read from the start. — gronostaj, May 02 '13 at 06:05

score 1 · Accepted Answer · answered May 02 '13 at 10:31

I've found the solution. That class had a custom add() method that rewrote the file everytime something was added. At the beginning of the loop there were 100 entries, but after it executed once only one entry was left. There was also some extra code that had always added those missing 99 entries.

Replacing add() with super.add() solved the problem.

readUTF works once, then throws EOFException

1 Answers1