Re: Example on JNI compilation
Am Samstag 18 April 2009 23:08:58 schrieb LCID Fire: > I'm currently stuck with compiling a JNI library, which java does not > recognize. I'm not too sure about what options I have to provide to > automake and which are already builtin. Does anybody know an example of > how a jni lib is built using automake? Hi, in my project: http://libmsgque.sourceforge.net/ you can find a implementation useable as template 1. download the sources 2. go into the "javamsgque" directory 3. don't forget to add the autoconf macros for JNI from the "m4" subdirectory and the "acinclude.m4" file mfg Andreas Otto
Re: Example on JNI compilation
On 4/20/2009 3:49 PM, Peter O'Gorman wrote: John Calcote wrote: On 4/18/2009 3:08 PM, LCID Fire wrote: I'm currently stuck with compiling a JNI library, which java does not recognize. I'm not too sure about what options I have to provide to automake and which are already builtin. Does anybody know an example of how a jni lib is built using automake? There are basically two steps to building JNI libraries: Note that on Mac OS X 10.4 and earlier, java will not load modules that do not have a ".jnilib" extension, so you should add somewhere in configure.ac, something like: case $host_os in *-darwin*) JNI_EXTRA_LDFLAGS="-shrext .jnilib" ;; esac AC_SUBST(JNI_EXTRA_LDFLAGS) then in your Makefile.am you can have: mylib_la_LDFLAGS = -module -avoid-version $(JNI_EXTRA_LDFLAGS) Peter Thanks Peter, I didn't know this. I guess it won't be long before this isn't really an issue for newer macs, as 10.6 will probably be released in June, thereby bringing 10.4 to end-of-life state. However, there will still be plenty of older mac users out there. I might as well ask this question here: We build a regular C/C++ shared library, and link our JNI stubs right into it, exporting the JNI interfaces right along side the native library interfaces. It seems to work well on the platforms we've tried it out on, and it saves a library. In fact, we do the same thing with our C# (mono) interfaces, so this library has a hefty exported API. Besides the issue you pointed out above where JNI libs require a specific extension, do you know of any other issues with doing this sort of thing? Thanks in advance, John
Re: Example on JNI compilation
John Calcote wrote: > On 4/18/2009 3:08 PM, LCID Fire wrote: >> I'm currently stuck with compiling a JNI library, which java does not >> recognize. I'm not too sure about what options I have to provide to >> automake and which are already builtin. Does anybody know an example >> of how a jni lib is built using automake? > There are basically two steps to building JNI libraries: Note that on Mac OS X 10.4 and earlier, java will not load modules that do not have a ".jnilib" extension, so you should add somewhere in configure.ac, something like: case $host_os in *-darwin*) JNI_EXTRA_LDFLAGS="-shrext .jnilib" ;; esac AC_SUBST(JNI_EXTRA_LDFLAGS) then in your Makefile.am you can have: mylib_la_LDFLAGS = -module -avoid-version $(JNI_EXTRA_LDFLAGS) Peter -- Peter O'Gorman http://pogma.com
Re: Example on JNI compilation
On 4/18/2009 3:08 PM, LCID Fire wrote: I'm currently stuck with compiling a JNI library, which java does not recognize. I'm not too sure about what options I have to provide to automake and which are already builtin. Does anybody know an example of how a jni lib is built using automake? There are basically two steps to building JNI libraries: 1. Use the javah utility to generate JNI prototypes in C-language header files from your Java source code. 2. Compile the C-language JNI sources (including the headers generated in step 1) into a library. Step 1 above is pure Java-speak, and Automake has little built-in functionality for it. Step 2, however is pure gcc, and Automake has no trouble with it. For an example of how to integrate javah operations into Makefile.am so you can do it all from Automake, see Chapter 6 of this online book at freesoftwaremagazine.com: http://www.freesoftwaremagazine.com/books/agaal/autotools_example Search for the text, "Building the JNI C++ sources". Regards, John
Re: Example on JNI compilation
* LCID Fire wrote on Mon, Apr 20, 2009 at 07:58:50PM CEST: > Ralf Wildenhues wrote: >> * LCID Fire wrote on Sat, Apr 18, 2009 at 11:08:58PM CEST: >>> I'm currently stuck with compiling a JNI library, which java does not >>> recognize. I'm not too sure about what options I have to provide to >>> automake and which are already builtin. Does anybody know an example >>> of how a jni lib is built using automake? >> >> How would one go about doing it without automake? > Like this: > gcc -c -fPIC myfile.c -o myfile.o > gcc -shared -lacl -Wl,-soname,mylib.so -o mylib.so myfile.o I can't see anything JNI'ish or java'ish in the above, so, assuming mylib.so is destined for $(pkglibdir), pkglib_LTLIBRARIES = mylib.la mylib_la_SOURCES = myfile.c mylib_la_LDFLAGS = -module -avoid-version mylib_la_LIBADD = -lacl or I am still missing something that I haven't understood from your request. Cheers, Ralf
Re: Example on JNI compilation
Ralf Wildenhues wrote: Hello, * LCID Fire wrote on Sat, Apr 18, 2009 at 11:08:58PM CEST: I'm currently stuck with compiling a JNI library, which java does not recognize. I'm not too sure about what options I have to provide to automake and which are already builtin. Does anybody know an example of how a jni lib is built using automake? How would one go about doing it without automake? Like this: gcc -c -fPIC myfile.c -o myfile.o gcc -shared -lacl -Wl,-soname,mylib.so -o mylib.so myfile.o
Re: Example on JNI compilation
Hello, * LCID Fire wrote on Sat, Apr 18, 2009 at 11:08:58PM CEST: > I'm currently stuck with compiling a JNI library, which java does not > recognize. I'm not too sure about what options I have to provide to > automake and which are already builtin. Does anybody know an example of > how a jni lib is built using automake? How would one go about doing it without automake? Cheers, Ralf
Example on JNI compilation
I'm currently stuck with compiling a JNI library, which java does not recognize. I'm not too sure about what options I have to provide to automake and which are already builtin. Does anybody know an example of how a jni lib is built using automake?
