@Override
  public void append(LoggingEvent event) {
    // 上下文必须在AsyncAppender中进行包装,而其子线程和LogContext不在同一个线程中
    LogContext logContext = LogContext.getLogContext();
    if (logContext != null) {
      wrapMessage(logContext, event);
    }

    super.append(event);
  }
 /**
  * 设置队列长度
  *
  * @param size
  */
 public void setQueueSize(int size) {
   super.setBufferSize(size);
 }
 /**
  * Close this appender instance. The underlying stream or writer is also closed.
  *
  * <p>Closed appenders cannot be reused.
  *
  * @see #setWriter
  * @since 0.8.4
  */
 public synchronized void close() {
   super.close();
   appender.close();
 }
 @Override
 public void activateOptions() {
   appender.activateOptions();
   super.activateOptions();
 }
 /** Set the name of this Appender. */
 public void setName(String name) {
   super.setName(name);
   appender.setName(name);
 }