LOG处理SystemLogger.java

<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> import java.io.*; import java.util.*; import java.text.*; public class SystemLogger implements Runnable { public static int DEBUG = 0; public static int INFO = 1; public static int NOTICE = 2; public static int WARNING = 3; public static int ERROR = 4; public static int FATAL_ERROR = 5; public static int MIN_LEVEL = 0; public static int MAX_LEVEL = 5; public static int DAILY = 0; public static int HOURLY = 1; private static String[] LEVEL_DESC = { " ", " ", " ", "", " ", " ", }; private PrintWriter out; private int level = DEBUG; private DateFormat dateFormat = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss"); private boolean needToCloseOutput = false; private Thread thread = null; private String filePrefix = ""; private int switchingFrequency = DAILY; private Vector listeners = null; // --- Start of Singleton Pattern ----------------------- // private static SystemLogger instance = null; public static SystemLogger getInstance() { if (instance == null) { instance = new SystemLogger(); } return instance; } protected SystemLogger() { // Set default output to System.out: setOutput(System.out); } // --- End of Singleton Pattern ------------------------- // public synchronized void setOutput( String filePrefix, boolean autoSwitching, int frequency) { this.filePrefix = filePrefix; this.switchingFrequency = (frequency != DAILY && frequency != HOURLY) ? DAILY : frequency; if (autoSwitching) { if (thread == null) { thread = new Thread(this); thread.start(); } } else { if (thread != null) { Thread t = thread; thread = null; t.interrupt(); } setOutput(filePrefix ".log"); } } private synchronized void setOutput(String filename) { PrintWriter newOutput = null; try { newOutput = new PrintWriter(new FileOutputStream(filename, true)); } catch (IOException e) { logError("System logger failed to open file " filename, e); return; } if (out != null && needToCloseOutput) { logInfo("System logger output closed and switched to " filename); out.close(); } out = newOutput; needToCloseOutput = true; logInfo("System logger started with output to " filename); logInfo("System logger option (autoSwitching=" ((thread == null) ? "false" : "true, frequency=" ((switchingFrequency == DAILY) ? "daily" : ((switchingFrequency == HOURLY) ? "hourly" : "unknown"))) ")" ); } private synchronized void recycleOutput() { SimpleDateFormat df; if (switchingFrequency == DAILY) { df = new SimpleDateFormat("yyyy-MM-dd"); } else { df = new SimpleDateFormat("yyyy-MM-dd-HH"); } String filename = filePrefix "-" df.format(new Date()) ".log"; setOutput(filename); } public void run() { int currentDayOfMonth = -1; int currentHourOfDay = -1; for (;;) { Calendar calendar = Calendar.getInstance(); calendar.setTime(new Date()); int dd = calendar.get(Calendar.DAY_OF_MONTH); int hh = calendar.get(Calendar.HOUR_OF_DAY); int mm = calendar.get(Calendar.MINUTE); int ss = calendar.get(Calendar.SECOND); int ms = calendar.get(Calendar.MILLISECOND); if ((switchingFrequency == DAILY && (dd != currentDayOfMonth)) || (switchingFrequency == HOURLY && (dd != currentDayOfMonth || hh != currentHourOfDay))) { recycleOutput(); } logDebug("Calendar dd=" dd " hh=" hh " mm=" mm " ss=" ss " ms=" ms); currentDayOfMonth = dd; currentHourOfDay = hh; int sleep; if (switchingFrequency == DAILY) { sleep = 86400000 - (((hh * 60 mm) * 60 ss) * 1000 ms); } else { sleep = 3600000 - ((mm * 60 ss) * 1000 ms); } sleep = 500; // add 0.5 sec. for tolerance. logDebug( "System logger will switch its output to a new file after " sleep " milliseconds."); try { Thread.sleep(sleep); } catch (InterruptedException e) { logDebug("System logger auto-switching thread interrupted"); } if (Thread.currentThread() != this.thread) { break; } } logDebug("System logger auto-switching thread terminated."); } public synchronized void setOutput(OutputStream os) { if (out != null && needToCloseOutput) { logInfo("System logger output closed."); out.close(); out = null; } out = new PrintWriter(os); needToCloseOutput = false; logInfo( "System logger started with output as " ((os == System.out) ? "System.out" : "OutputStream " os.toString())); } public synchronized void setOutput(PrintWriter writer) { if (out != null && needToCloseOutput) { logInfo("System logger output closed."); out.close(); out = null; } out = writer; needToCloseOutput = false; logInfo("System logger started with output as PrintWriter " writer.toString()); } public synchronized void close() { logInfo("System logger requested to be closed down."); if (thread != null) { Thread t = thread; thread = null; t.interrupt(); try { wait(500); } catch (InterruptedException e) {} } if (out != null && needToCloseOutput) { out.close(); out = null; } listeners = null; } /** Specifies the level of the messages to be logged. */ public void setLevel(int level) { this.level = level; } /** Returns the current logging level. @return the current logging level. */ public int getLevel() { return this.level; } /** Logs a message with the specified log level and associated exception. @param logLevel the level of the message. @param msg the message string. @param e an optional exception associated with the message. */ public void log(int logLevel, String msg, Exception e) { if (out == null || this.level > logLevel) { return; } logLevel = logLevel < MIN_LEVEL ? MIN_LEVEL : logLevel; logLevel = logLevel > MAX_LEVEL ? MAX_LEVEL : logLevel; String line; synchronized(this) { line = "# " dateFormat.format(new Date()) " " LEVEL_DESC[logLevel] " " msg; out.println(line); if (e != null) { e.printStackTrace(out); } out.flush(); } if (listeners != null) { SystemLoggerListener listener; SystemLoggerEvent evt = new SystemLoggerEvent(this, logLevel, msg, e, line); for (Enumeration en = ((Vector)listeners.clone()).elements(); en.hasMoreElements(); ) { try { listener = (SystemLoggerListener)en.nextElement(); listener.messageLogged(evt); } catch (Exception e1) {} } } } /** Logs a debug message with an exception. @param msg the message string @param e the excetpion. */ public void logDebug(String msg, Exception e) { log(DEBUG, msg, e); } /** Logs a debug message without an exception. @param msg the message string @param e the excetpion. */ public void logDebug(String msg) { log(DEBUG, msg, null); } /** Logs an info message with an exception. @param msg the message string @param e the excetpion. */ public void logInfo(String msg, Exception e) { log(INFO, msg, e); } /** Logs an info message without an exception. @param msg the message string @param e the excetpion. */ public void logInfo(String msg) { log(INFO, msg, null); } /** Logs a notice message with an exception. @param msg the message string @param e the excetpion. */ public void logNotice(String msg, Exception e) { log(NOTICE, msg, e); } /** Logs a notice message without an exception. @param msg the message string @param e the excetpion. */ public void logNotice(String msg) { log(NOTICE, msg, null); } /** Logs a warning message with an exception. @param msg the message string @param e the excetpion. */ public void logWarning(String msg, Exception e) { log(WARNING, msg, e); } /** Logs a warning message without an exception. @param msg the message string @param e the excetpion. */ public void logWarning(String msg) { log(WARNING, msg, null); } /** Logs an error message with an exception. @param msg the message string @param e the excetpion. */ public void logError(String msg, Exception e) { log(ERROR, msg, e); } /** Logs an error message without an exception. @param msg the message string @param e the excetpion. */ public void logError(String msg) { log(ERROR, msg, null); } /** Logs a fatal error message with an exception. @param msg the message string @param e the excetpion. */ public void logFatalError(String msg, Exception e) { log(FATAL_ERROR, msg, e); } /** Logs a fatal error message without an exception. @param msg the message string @param e the excetpion. */ public void logFatalError(String msg) { log(FATAL_ERROR, msg, null); } public synchronized void addSystemLoggerListener( SystemLoggerListener listener) { if (listeners == null) { listeners = new Vector(); } listeners.addElement(listener); } public void removeSystemLoggerListener( SystemLoggerListener listener) { if (listener != null) { listeners.removeElement(listener); } } }