log4j: 不同的类使用不同的日志

    public final static String LOGGER_NAME = "MyFunction";
    private static Logger logger = Logger.getLogger(LOGGER_NAME);
    
    static {
        try {
            File logFile = new File(MainService.getWorkDir(), "MyFunction.log");
            FileAppender fileAp = new FileAppender(
                    new PatternLayout("%d %5p (%c:%L) - %m%n"), 
                    logFile.getAbsolutePath(), 
                    true);
            logger.setLevel(Level.DEBUG);
            logger.addAppender(fileAp);
        } catch (Exception e) {
            logger.error("", e);
        }
    };