Hi ,
 Just try this 

 <env-entry>
   <env-entry-name>jdbcPassword</env-entry-name>
   <env-entry-type>java.lang.String</env-entry-type>
   <env-entry-value> </env-entry-value>
 </env-entry>
 
that is just empty space between <env-entry-value>.

Rgds
-Sugandha

--- Jiri Vorac <j.vo@v...> wrote:
> I need in my deployment descriptor something like
> this:
> 
> <env-entry>
>   <env-entry-name>jdbcPassword</env-entry-name>
>   <env-entry-type>java.lang.String</env-entry-type>
>   <env-entry-value></env-entry-value>
> </env-entry>
> 
> It means: jdbcPassword="";
> 
> But when deploying (I use jBoss server), it
> throws NullPointerException.
> 
> Is there easy solution?  Jirka