Actually, I get my connection object from the Tomcat JNDI where my web application is deployed. There is a connection property setting that I could do in order to have my CLOB inserted (I changed my BLOD datatype to CLOB) and this is the "SetBigStringTryClob", "true". But I was unable to set this in the Resource configuration in the context.xml of my Tomcat. So the Connection that I get from Tomcat seems not to fit for this situation. So I had to create another explicit Connection through my application and set this property explicitly there and do the insert and retrieval which now seems to work fine.
The following is what I have in the context.xml of my Tomcat
I really cannot understand why the connectionProperties is not respected by Tomcat. If I run using this setting I still keep getting the below exception... (sorry it is in German)
But however when having specifically creating a Connection object through my application rather than using Tomcat JNDI look up, I was able to get it done.