import org.apache.logging.log4j.core.appender.AbstractOutputStreamAppender; //导入依赖的package包/类
public static void flushAll() {
	final LoggerContext logCtx = ((LoggerContext) LogManager.getContext());
	for(final org.apache.logging.log4j.core.Logger logger : logCtx.getLoggers()) {
		for(final Appender appender : logger.getAppenders().values()) {
			if(appender instanceof AbstractOutputStreamAppender) {
				((AbstractOutputStreamAppender) appender).getManager().flush();
			}
		}
	}
}
 

import org.apache.logging.log4j.core.appender.AbstractOutputStreamAppender; //导入依赖的package包/类
public static void addFileAppender(String filename) {
    if (instance == null) {
        LOGGER.error("CustomFileAppender hasn't been initalized, ignoring output "
                     + filename);
        return;
    }

    final AbstractOutputStreamAppender<? extends OutputStreamManager> appender;
    if (mmap_appender)
        appender = MemoryMappedFileAppender.createAppender(filename,
                                                           "false", filename,
                                                           "false", "8192", "false",
                                                           instance.getLayout(),
                                                           instance.getFilter(),
                                                           "false", "false",
                                                           new DefaultConfiguration());
    else
        appender = FileAppender.createAppender(filename,
                                               "false", "false",
                                               filename,
                                               "false", "false",
                                               "true", "8192",
                                               instance.getLayout(),
                                               instance.getFilter(),
                                               "false", "false",
                                               new DefaultConfiguration());

    LOGGER.info("registering custom logfile '{}'", appender);
    instance.appenders.add(appender);
}