private static void loadInterpreter() {
		try {
			String className = props.getProperty("interpreter.class");
			if ("".equals(className)) 
				className = "com.xl.hbase.InterpreterImpl";
			Class<?> clazz = Class.forName(className);
			intp =  (Interpreter)clazz.newInstance();
		} catch (ClassNotFoundException e) {
			LOG.error("class not found", e);
		} catch (InstantiationException e) {
			LOG.error("instantiation exception", e);
		} catch (IllegalAccessException e) {
			LOG.error("illegal access", e);
		}
	}