You need to change some alternative for a certain application
This is by design
I do not like the alternatives system on the command line. I like to use galternatives which has a nice GUI which makes it possible to change settings with the mouse.
To install galternatives you just use:
apt-get install galternatives
To change e.g. the java execution environment from gij to sun java, you just click on java and select the appropriate version you would like to start.
About the Author
Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux in different European countries and different European languages. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform where he is one of the most important contributors and the main developer.