private static FilterInitializer[] getFilterInitializers(Configuration conf) {
    if (conf == null) {
      return null;
    }

    Class<?>[] classes = conf.getClasses(FILTER_INITIALIZERS_PROPERTY);
    if (classes == null) {
      return null;
    }

    FilterInitializer[] initializers = new FilterInitializer[classes.length];
    for (int i = 0; i < classes.length; i++) {
      initializers[i] = (FilterInitializer) ReflectionUtils.newInstance(classes[i]);
    }
    return initializers;
  }
Get an array of FilterConfiguration specified in the conf
hbase-http/src/main/java/org/apache/hadoop/hbase/http/HttpServer.java