static String getParentPackageName(final String packageOrClassName) {
        if (packageOrClassName.isEmpty()) {
            return null;
        }
        final int lastDotIdx = packageOrClassName.lastIndexOf('.');
        return lastDotIdx < 0 ? "" : packageOrClassName.substring(0, lastDotIdx);
    }
static String getParentPackageName ( final String packageOrClassName ) { if ( packageOrClassName . isEmpty ( ) ) { return null ; } final int lastDotIdx = packageOrClassName . lastIndexOf ( '.' ) ; return lastDotIdx < 0 ? "" : packageOrClassName . substring ( 0 , lastDotIdx ) ; }
Get the name of the parent package of a parent, or the package of the named class.

@param packageOrClassName
The package or class name.
@return the parent package, or the package of the named class, or null if packageOrClassName is the root
package ("").