javac JNIDemo.java
gcc -I /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/include/ -I /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0/include/linux/ -fPIC -shared -o libnative.so native.c
export LD_LIBRARY_PATH=.
java JNIDemo 