snaker-jfinal/src/main/java/org/snaker/jfinal/access/JfinalAccess.java
protected Connection getConnection() throws SQLException {
        Config config = JfinalHelper.getConfig();
		Connection conn = config.getThreadLocalConnection();
		if(conn == null) {
			conn = config.getConnection();
            conn.setAutoCommit(true);
		}
		return conn;
	}
protected Connection getConnection() throws SQLException {
        Config config = JfinalHelper.getConfig();
		Connection conn = config.getThreadLocalConnection();
		if(conn == null) {
			conn = config.getConnection();
            conn.setAutoCommit(true);
		}
		return conn;
	}
从jfinal的threadlocal中获取数据库连接