<p>Traditional logfile analytics tools (awstats, statcounter) or general web analytics (google analytics, yahoo web analytics) are not suitable for analyzing traffic on servlets. Is there a good alternative to log messages using a logging framework (log4j for example) and to write a custom analytics software for these?</p>

I suppose this is not the answer you hoped for but it is unavoidable that anyone with administrative rights will be able to browse and edit information in the database.
You cannot change this.
Perhaps you could consider WHY you want to prevent this kind of access?
I expect you want to prevent tampering or accidental corruption of the data?
If that is the reason then you can go a long way to prevent corruption by adding constraints to your database.  Add foreign key constraints, uniqueness constraints, everything that will help prevent data corruption.
Then an administrator would need to deliberately undo these constraints before they tamper, which would prevent most accidental corruption but of course not prevent malicious vandalism.
If you are concerned about protection of your intellectual property, you could encrypt the programmatic components (stored procedures and views and functions).  This kind of encryption is not very strong but prevents casual inspection.
Encryption is added by using the
```
```
WITH ENCRYPTION
```
```
clause in your CREATE or ALTER statements.