public static void appendLog(String logFileName, String appendLog) {

		// log file
		if (logFileName==null || logFileName.trim().length()==0) {
			return;
		}
		File logFile = new File(logFileName);

		if (!logFile.exists()) {
			try {
				logFile.createNewFile();
			} catch (IOException e) {
				logger.error(e.getMessage(), e);
				return;
			}
		}

		// log
		if (appendLog == null) {
			appendLog = "";
		}
		appendLog += "\r\n";

		// append file content
		FileOutputStream fos = null;
		try {
			fos = new FileOutputStream(logFile, true);
			fos.write(appendLog.getBytes("utf-8"));
			fos.flush();
		} catch (Exception e) {
			logger.error(e.getMessage(), e);
		} finally {
			if (fos != null) {
				try {
					fos.close();
				} catch (IOException e) {
					logger.error(e.getMessage(), e);
				}
			}
		}

	}
append log

@param logFileName
@param appendLog
larkmidtable-web/larkmt-core/src/main/java/com/larkmt/core/log/JobFileAppender.java