log4j2以编程方式更改滚动文件追加最大文件

Question

我正在处理一个使用log4j2（使用log4j2.xml初始化参数）并加载记录器的应用程序。当应用程序运行时，我需要以编程方式重写一些参数，例如更改日志级别和滚动文件附加器属性。我可以使用以下方法更改日志级别：

/**
         * @param logger Logger instance
         * @param level New log level to be applied on the logger instance
         */
        private void setLoggerLevel(Logger logger, Level level) {
            LoggerContext context = (LoggerContext) LogManager.getContext(false);
            Configuration config = context.getConfiguration();
            LoggerConfig loggerConfig = getLoggerConfig(logger.getName());


            Logger rootLogger = LogManager.getRootLogger();
            if(logger !=  rootLogger && loggerConfig != config.getLoggerConfig(rootLogger.getName()))
            {
                loggerConfig.setLevel(level);
                context.updateLoggers();
            }
        }

现在我尝试使用RollingFile appender的属性来解决同样的问题。然而，我仍然停留在如何修改现有的RollingFile appender的属性上

Logger applicationLogger = LogManager.getLogger(logName);

if (applicationAppender instanceof RollingFileAppender) {

    // Configure max properties of rolling file appender here
    if (maxLogFiles != null) {

        LoggerContext context = (LoggerContext) LogManager.getContext(false);
        Configuration config = context.getConfiguration();
        // Copied code from lib
        DefaultRolloverStrategy newStrategy = DefaultRolloverStrategy.createStrategy(String.valueOf(maxLogFiles), null, null,
                String.valueOf(Deflater.DEFAULT_COMPRESSION), null, true, config);

        // How to modify the existing appender?

    }

}

Answer 1

你走对了。创建新策略后，请执行以下操作：

Appender appender = config.getAppender("MyRollingFile");
if (appender != null && appender instanceof RollingFileAppender) {
    ((RollingFileAppender) appender).getManager().setRolloverStrategy(newStrategy);
}

如果要修改所有RollingFileAppenders,请执行以下操作：

Map<String, Appender> appenders = config.getAppenders();
for (Appender appender : appenders.values()) {
    if (appender instanceof RollingFileAppender) {
        ((RollingFileAppender) appender).getManager().setRolloverStrategy(newStrategy);
    }
}