Finishing touches

The book is in its final stages. Right now I am putting the finishing touches to the illustrations and going through the editors’ most recent comments and suggestions. Takes a lot more time than expected, though…

Illustrating

Comments

Post a Comment

Popular posts from this blog

SAXParseException: -1:-1: Premature End Of File - Misleading error

Today I had to look at a piece of code a colleague had written, using my XPathAccessor class. She used it in a servlet which gets XML formatted requests. As those are generated by an external 3rd party tool we agreed on some XML schema definitions. Everything they send us needs to conform to its corresponding schema, each reply we send gets validated against a different set.In order to allow independent testing on either side, we provided a little test kit that allows testing our system without having to set up a servlet engine. Basically it just takes a file, reads it into a String and hands that to the handler.First it gets parsed without validation. This is necessary to find out which type of request we were send (the address is the same for all of them). After the root element is known, it will be read again, this time using the right schema to verify the request.Once that is done, some reply is put together and sent back to the client. So far, so good.When I looked at the code I …
Read more

Can't start server: Bind on TCP/IP port: No such file or directory

(Also see the follow-up post about some progress)Today I was (again) facing a log file from a machine that had for some reason not been able to start a temporary MySQL daemon during the night to prepare for a streaming MySQL slave installation. The necessary 2nd daemon had created its new ibdata files, however just after that aborted the startup process with the following message:Can't start server: Bind on TCP/IP port: No such file or directory 071001 23:09:55 [ERROR] Do you already have another mysqld server running on port: 3310 ? 071001 23:09:55 [ERROR] Aborting 071001 23:09:55 [Note] mysql\bin\mysqld.exe: Shutdown completeAs you can see, the port is a different one from the default MySQL port, so I can be sure there was no conflict with the primary instance. Even more curiously the same process has been working on that and other machines flawlessly for some time. However I remember having seen this message once before, but back then I did not have the time to look into it any…
Read more

FindBugs - Writing custom detectors (Part 1)

Some words in advance...Recently I wrote about multi-threading problems with java.util.Calendar and java.text.DateFormat. The last sentence was So maybe it is time to search your code for all static usages of the Calendar and various ...Format classes, before you start getting strange errors.Searching code is not very practical, especially if you do it manually. Everyone knows you can look at code for hours, without seeing an problem - and as soon as it has reached production systems it starts breaking up in various ways :-)Fortunately smart and reknown people have devised ways of making the computer look for bugs automatically. Amongst others, FindBugs is a very nice - and free - tool that analyzes your Java application's compiled bytecode and looks for numerous so called bug patterns. Those patterns are divided into categories, such as "Bad practice", "Correctness", "Multithreaded correctness", "Performance" and some more. Each of them lo…
Read more