自己动手实现一个轻量极log

大家可能每天都在用apache 的log4j在打log,可大家有没想过它的内部是怎么实现的呢，我在这里实现的一个简单的log,希望对大家了解打log的过程有所了解。
由于实现的比较简单，没有加入对log level的支持。

public class AuditLogManager {

	private static LogFileThread logFile = null;
	private static boolean bWrite = true;
   
	public static void writeInfo(String sInfo) {

		if (!bWrite)
			return;

		if (logFile == null) {
			logFile = new LogFileThread();
			logFile.start();
		}

		logFile.writeInfo(sInfo);
	}


}

class LogFileThread extends Thread {

	private static FileOutputStream outLogFile = null;
	private static boolean bInit = false;
	private static boolean bErr = false;
	private static Vector vInfo = new Vector();

	public LogFileThread() {

	}

	private void init(String fileName) {
		try {

			if (bInit)
				return;

			String logFile = "c:/worksapce/log";
			File f = new File(logFile);
			f.mkdirs();
			logFile += "/AuditLog_" + fileName + ".log";
			outLogFile = new FileOutputStream(logFile, true);

		} catch (Exception e) {
			bErr = true;
			e.printStackTrace();
		}
		bInit = true;
	}

	public void writeInfo(String info) {

		if (info == null)
			return;
		procInfo(info, true);

	}

	private String getInfo() {

		return procInfo(null, false);

	}

	private synchronized static String procInfo(
		String info,
		boolean bPutInfo) {

		if (bErr) {
			vInfo.clear();
			return null;
		}

		String sInfo = null;

		try {

			if (bPutInfo) {
				if (info != null)
					vInfo.add(info);

			} else {
				if (vInfo.size() > 0) {
					sInfo = (String) vInfo.get(0);
					vInfo.remove(0);

				}
			}

		} catch (Exception e) {
			bErr = true;
			e.printStackTrace();
		}
		return sInfo;
	}

	private void writeFile(String info) {
		try {
			if (info == null)
				return;
			outLogFile.write(info.getBytes());
		} catch (Exception e) {
			bErr = true;
			e.printStackTrace();
		}
	}

	private void close() {
		try {
			bInit = false;
			bErr = false;
			if (outLogFile != null)
				outLogFile.close();
			outLogFile = null;
		} catch (Exception e) {
			e.printStackTrace();
		}

		bInit = false;
	}

	public void run() {
		try {

			String oldDate = null;
			while (true) {

				String curDate = DateTime.getCurrentDate(0);

				if (oldDate == null || !oldDate.equalsIgnoreCase(curDate)) {
					oldDate = curDate;
					close();
					init(oldDate);
				}

				String curTime = DateTime.getCurrentTimestamp(0);
				String ss = formatInfo(curTime);
				writeFile(ss);
				if (ss == null)
					sleep(1000);

			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	private String formatInfo(String time) {

		String sInfo = procInfo(null, false);
		if (sInfo == null)
			return null;
		String sh = "*******" + time + "*******\r\n\r\n";
		sh += sInfo;
		sh += "\r\n\r\n*******  End  *******\r\n\r\n";
		return sh;

	}

	protected void finalize() {
		try {
			System.out.println("Close  Log Manager");
			this.interrupt();
			outLogFile.close();
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}