To compile the native library for DirectIOReader, make sure that $JAVA_HOME
points to a JDK 1.6. Invoke the following command:

%> gcc -o libreaddirect.so -shared -Wl,-soname,libreaddirect.so \
 > -I$JAVA_HOME/include -I$JAVA_HOME/include/linux org_xtreemfs_sandbox_DirectIOReader.c

The output will be a shared library named "libreaddirect.so". Make sure that the property
"java.library.path" points to the directory where this library is located when starting
the Java VM, e.g. by adding the option "-Djava.library.path=<directory containing lib>".