public final class StringUtils { public static final String LIBRARY_NAME = "stringUtils"; static { System.loadLibrary(LIBRARY_NAME); } private StringUtils() { } public static native boolean isAlpha(String string); public static native boolean isEmpty(String string); public static void main(String[] args) { System.out.println(StringUtils.isAlpha("sureIs")); System.out.println(StringUtils.isAlpha("nope!")); System.out.println(StringUtils.isEmpty(" ")); System.out.println(StringUtils.isEmpty("nope")); } }