I think Netbeans can do that, I have used it to generate class diagrams from code a few times.

Sounds like you trying to copy someone else's work !!!

No I am not trying to copy the code. Infact I have a component written in java but I need to translate it into c/c++
as my own application is in c/c++. To understand the code is not necessary for me but the way to use it is necessary
for me. Where as the matter of the copy. The java code I have is also written by my company's developers but it is
old code and now it is upto me to use it. I dont want to shift to java and thus want the code to get converted in c++
as I have very student level experience of java

regards,

You should make up your mind if the application is C or it is C++...
There is a hell of difference!

C++

You need to write it manually , many libraries (e.g. network) does not have anything remotely equivalent in C++ language.