I have an hsqlDB server running, with version 2.2.6, and a client application that remotely accesses this server, client version is 2.3.3.
Now I started a new project and wanted to access the server, but get an exception. The server side log tells me:
org.hsqldb.HsqlException: Client driver version greater than '2.3.4.0' is required. HSQLDB server version is 'version'
The new client version really was 4.2.0, then I downgraded to 2.3.4 with the same result. Further downgrade to 2.3.3 avoided the problem, but can't be called a solution.
I don't dare upgrade the server (never touch a running system).
One strange thing that strikes me is the
version is 'version'
part of the error message.
That looks as if someone had forgotten to code the real version number. Alas, I can't find source code.
Question is: has anyone seen or heard of that problem, and knows more about the reason?
The client-server protocol changes in some versions of HSQLDB. Each version of the Server can be accessed from clients that are compatible with it.
There was a bug (now fixed) only in error text reporting the mismatch. The actual check for compatibility does work, as you found out.
You do not need to change your server, as it works fine. Just use a compatible client.