private boolean processProperties(Properties properties) {
		String kind = properties.getProperty("kind");
		if (kind.equalsIgnoreCase("t1") || kind.equalsIgnoreCase("t3")) {
			String author_id = SQL.getInstance().get_author_id(properties.getProperty("author"));
			if (author_id == null) {
				return false;
			}
		}
		
		if (kind.equalsIgnoreCase("t1")) { //comment
			SQL.getInstance().insertComment(properties);
		} else if (kind.equalsIgnoreCase("t2")) { //author
			SQL.getInstance().insertAuthor(properties);
			synchronized(crawlTaskList) {
				AuthorCrawler ac = new AuthorCrawler(properties.getProperty("name"));
				while (crawlTaskList.remove(ac));
			}
		} else if (kind.equalsIgnoreCase("t3")) { //link
			SQL.getInstance().insertPost(properties);
		}
		return true;
	}