Pramod Kankure

Demo2 does not compile as you are using a wrapper class Byte of smaller primitive size to hold the integer result generated by compound assignment.
In case of Demo2 following things happen

1) b is unboxed from Byte wrapper to byte and then incremented by 10
2) The result is to be narrowed down to byte
3) The result is to be boxed back to Byte wrapper.



JAVA does not support boxing of a result that is narrowed down. You can use a bigger wrapper like Long or Integer and can still use compound operator .

In case of Demo1, JAVA does not have to box back a result at all as it is assigned to a byte primitive type.

These classes are loosely coupled meaning you are sending messages between your class and these classes like String so they work together. There is nothing like zero coupling.... At least classes are coupled using messaging.

I think you have to use { in your stored procedure call. So try con.prepareCall("{ call storeprocedurename(?, ?) }");

Servlet is not a right choice to create a server process. Are you using GenericServlet or HTTPServlet?

Which version of JDBC driver you are using? You may want to upgrade it, if it is not a recent one.

I was getting a similar problem. In my case the issue was with the way you specifiy URL_Pattern in Security_constraint. You should always prefix it with /faces/