Sharing a .h include file between a C project and Java

Question

I'm writing a newtowrk utility in Java that uses a lot of constants that are available in a .h file in a C project. In fact, the .h file is the authority as to what the values actually are.
Is there a standard way or has anyone written a utility that will pull in a C include file to generate constants for Java objects to use?
In C I have in protocols.h:
#define ETHERTYPE_IPV4 0x800
#define ETHERTYPE_FOO 0xF00to turn into
public class ProtocolsDotH {
public static final int ETHERTYPE_IPV4 = 0x800;
public static final int ETHERTYPE_FOO = 0xF00;
}Or something like that. I could invoke the utility in the make file that compiles and jars my Java app. Any guidance?

Answer 1

You could use SWIG, the Simple Wrapper Interface Generator (http://www.swig.org). But if you just have a few simple constants this seems a bit heavyweight.
I can't seem to get SWIG to put the literal values right into the Java file. Here's how you might invoke it with a header file called stuff.h:
[cdb@merlin forum]$ cat stuff.h
#define FROB 0x1234
#define MEAT 0xdeadbeef
[cdb@merlin forum]$ swig -java -module JStuff stuff.hThis will create some files:
JStuff.java  JStuffJNI.java  stuff.h  stuff_wrap.cwith JStuff.FROB and JStuff.MEAT, but I don't know how to get swig to put the values right in the Java file. It actually calls a JNI method that it generates in stuff_wrap.c to set the constant values.
Too bad, but there might be a way, probably via a ".i" file to swig, to put literal constants in the source.
I guess the bottom line is:
Probably a simple one-line grep/sed command or perl script would do the trick though.