public static Class<? extends FlushPolicy> getFlushPolicyClass(TableDescriptor htd,
    Configuration conf) throws IOException {
    String className = htd.getFlushPolicyClassName();
    if (className == null) {
      className = conf.get(HBASE_FLUSH_POLICY_KEY, DEFAULT_FLUSH_POLICY_CLASS.getName());
    }
    try {
      Class<? extends FlushPolicy> clazz = Class.forName(className).asSubclass(FlushPolicy.class);
      return clazz;
    } catch (Exception e) {
      LOG.warn("Unable to load configured flush policy '" + className + "' for table '"
        + htd.getTableName() + "', load default flush policy "
        + DEFAULT_FLUSH_POLICY_CLASS.getName() + " instead", e);
      return DEFAULT_FLUSH_POLICY_CLASS;
    }
  }
Get FlushPolicy class for the given table.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/FlushPolicyFactory.java