private static <T> T attemptLoad(
            final Class<T> ofClass,
            final String className) {
        if (LOG.isLoggable(Level.FINEST)) {
            LOG.finest("Attempting service load: " + className);
        }
        Level level;
        Throwable thrown;
        try {
            Class<?> clazz = Class.forName(className);
            if (!ofClass.isAssignableFrom(clazz)) {
                if (LOG.isLoggable(Level.WARNING)) {
                    LOG.warning(clazz.getName() + " is not assignable to "
                            + ofClass.getName());
                }
                return null;
            }
            return ofClass.cast(clazz.newInstance());
        } catch (LinkageError ex) {
            level = Level.FINEST;
            thrown = ex;
        } catch (ClassNotFoundException ex) {
            level = Level.FINEST;
            thrown = ex;
        } catch (InstantiationException ex) {
            level = Level.WARNING;
            thrown = ex;
        } catch (IllegalAccessException ex) {
            level = Level.WARNING;
            thrown = ex;
        }
        LOG.log(level,
                "Could not load " + ofClass.getSimpleName()
                + " instance: " + className,
                thrown);
        return null;
    }
private static < T > T attemptLoad ( final Class < T > ofClass , final String className ) { if ( LOG . isLoggable ( Level . FINEST ) ) { LOG . finest ( "Attempting service load: " + className ) ; } Level level ; Throwable thrown ; try { Class < ? > clazz = Class . forName ( className ) ; if ( ! ofClass . isAssignableFrom ( clazz ) ) { if ( LOG . isLoggable ( Level . WARNING ) ) { LOG . warning ( clazz . getName ( ) + " is not assignable to " + ofClass . getName ( ) ) ; } return null ; } return ofClass . cast ( clazz . newInstance ( ) ) ; } catch ( LinkageError ex ) { level = Level . FINEST ; thrown = ex ; } catch ( ClassNotFoundException ex ) { level = Level . FINEST ; thrown = ex ; } catch ( InstantiationException ex ) { level = Level . WARNING ; thrown = ex ; } catch ( IllegalAccessException ex ) { level = Level . WARNING ; thrown = ex ; } LOG . log ( level , "Could not load " + ofClass . getSimpleName ( ) + " instance: " + className , thrown ) ; return null ; }
Attempts to load the specified implementation class.
Attempts will fail if - for example - the implementation depends
on a class not found on the classpath.

@param className implementation class to attempt to load
@return service instance, or {@code null} if the instance could not be
loaded