RollingFileAppender.java 文件源码

/**
   This method differentiates RollingFileAppender from its super
   class.

   @since 0.9.0
*/
protected
void subAppend(LoggingEvent event) {
  super.subAppend(event);
  if(fileName != null && qw != null) {
      long size = ((CountingQuietWriter) qw).getCount();
      if (size >= maxFileSize && size >= nextRollover) {
          rollOver();
      }
  }
 }