how to make jni.h be found?

In Ubuntu 12.04, I have jdk7 from sun/oracle installed. When locate jni.h, it prints multiple locations

/usr/lib/jvm/java-6-openjdk-amd64/include/jni.h
/usr/lib/jvm/jdk1.7.0_07/include/jni.h
...

In the header file generated by JDK, there is include <jni.h>, and currently it complains

fatal error: jni.h: No such file or directory.

In my Makefile, there is no specification of locations where jni.h is. And I am asking if possible to configure certain system parameter to make path of jni.h (say, /usr/lib/jvm/jdk1.7.0_07/include/jni.h) to be known when being compiled.

Solution 1:

You have to tell your compiler where is the include directory. Something like this:

gcc -I/usr/lib/jvm/jdk1.7.0_07/include

But it depends on your makefile.

Solution 2:

It needs both jni.h and jni_md.h files, Try this

gcc -I/usr/lib/jvm/jdk1.7.0_07/include \
  -I/usr/lib/jvm/jdk1.7.0_07/include/linux filename.c

This will include both the broad JNI files and the ones necessary for linux

Solution 3:

Installing the OpenJDK Development Kit (JDK) should fix your problem.

sudo apt-get install openjdk-X-jdk

This should make you able to compile without problems.

Solution 4:

Use the following code:

make -I/usr/lib/jvm/jdk*/include

where jdk* is the directory name of your jdk installation (e.g. jdk1.7.0).

And there wouldn't be a system-wide solution since the directory name would be different with different builds of JDK downloaded and installed. If you desire an automated solution, please include all commands in a single script and run the said script in Terminal.

Solution 5:

I usually define my JAVA_HOME variable like so:

export JAVA_HOME=/usr/lib/jvm/java/

Therein are the necessary include files. I sometimes add the below to my .barshrc when I compile a lot of things that need it.