Question

I have received the following error message when trying to debug an application in NetBeans:

java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: board.Board$1

In the course of debugging I have had to insert ‘implements Serializable’ in a number of classes as the exception arose in the course of reading from a file that stores a large object. This has not been difficult as the class needing attention has been clear from the exception message. What has thrown me is the apparent anonymous inner class ‘Board$1’. I can’t for the life of me identify the source with ‘Board’ that is causing the problem. How can I do this?

As it’s a question of debugging practice rather than the specifics of the code (I think) I haven’t included it, but I can easily add that in if it helps.

Answer 1

Board$1 is the first anonymous class encountered in Board.java. For example:

class Board {
  public static void main(String[] args) {
    new Object() {}; // Board$1
    new Object() {}; // Board$2
  }
}

With an IDE like Eclipse, it’s easy to spot those anonymous classes in the outline view. I’m sure NetBeans has similar views: