RollingFileAppender.java 文件源码

public
synchronized
void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
                                                               throws IOException {
  super.setFile(fileName, append, this.bufferedIO, this.bufferSize);
  if(append) {
    File f = new File(fileName);
    ((CountingQuietWriter) qw).setCount(f.length());
  }
}