Bug 9150

When using the PropertyConfigurator containing a link to a FileAppender and the 
path to the requested log-file does not exist you get internal LOG4J-errors but 
no log-file.
From my point of view there's a bug in the method 'setFile(String file)' in the 
class 'FileAppender.java'.

I tried to solve the problem and find following solution (only with a few 
tests):


...
  public void setFile(String file)
  {
    // Trim spaces from both ends. The users probably does not want
    // trailing spaces in file names.
    String val = file.trim();
    fileName = val;

    File tempFile = new File(fileName);
    if (!(fileName.equals("")) && (tempFile.getParentFile() != null) && 
(tempFile.getParentFile().mkdirs()))
    {
      LogLog.debug("Create necessary directories '"+tempFile.getParentFile()+"' 
for log-file '"+tempFile.getName()+"'");
    }

    if ((!(fileName.equals(""))) && ((tempFile.canWrite() || !(tempFile.exists
()))))
    {
      LogLog.debug("Set filename for FileAppender '"+fileName+"'");
    }
    else
    {
      LogLog.debug("Can't set filename for FileAppender to '"+fileName+"'; 
possible no write-access or undefined path");
      fileName = null;
    }
  }
...