+If cmake complains that <b>jni could not be found</b>, you need to
+tell it where JNI header files are located. the following command
+should tell you:
+
+\verbatim
+$ locate jni.h
+/usr/lib/jvm/java-6-openjdk-amd64/include/jni.h
+/usr/lib/jvm/java-7-openjdk-amd64/include/jni.h
+\endverbatim
+
+If you have several version of jni installed (as in the example
+above), you need to check the version of java that is used by default
+on your machine (using javac -version), and pick the right one. Then
+set the JAVA_INCLUDE_PATH environment variable to the right path (note
+that we remove the filename jni.h from that path), and relaunch cmake.
+
+\verbatim
+$ export JAVA_INCLUDE_PATH=/usr/lib/jvm/java-6-openjdk-amd64/include/
+$ cmake .
+\endverbatim
+