private void readHeader() throws IOException {
  byte[] signatureBytes=new byte[8];
  for (int i=0; i < 8; i++)   signatureBytes[i]=plogStream.readByte();
  String stringifiedHeader=new String(signatureBytes,"US-ASCII");
  if (!stringifiedHeader.equals("PLOG\n \r ")) {
    throw new IOException("File header does not denote a PLOG file.");
  }
  int major_file_version=readSwappedInteger(plogStream);
  int minor_file_version=readSwappedInteger(plogStream);
  if (major_file_version != 1 || minor_file_version != 1) {
    throw new IOException("File header indicates version " + major_file_version + "."+ minor_file_version+ "; but it should be 1.1");
  }
  logger.info("Header and file version OK");
  return;
}

private void readHeader ( ) throws IOException { byte [ ] signatureBytes = new byte [ 8 ] ; for ( int i = 0 ; i < 8 ; i ++ ) signatureBytes [ i ] = plogStream . readByte ( ) ; String stringifiedHeader = new String ( signatureBytes , "US-ASCII" ) ; if ( ! stringifiedHeader . equals ( "PLOG\n \r " ) ) { throw new IOException ( "File header does not denote a PLOG file." ) ; } int major_file_version = readSwappedInteger ( plogStream ) ; int minor_file_version = readSwappedInteger ( plogStream ) ; if ( major_file_version != 1 || minor_file_version != 1 ) { throw new IOException ( "File header indicates version " + major_file_version + "." + minor_file_version + "; but it should be 1.1" ) ; } logger . info ( "Header and file version OK" ) ; return ; }
read the plog file header , checking it ' s really a plog file and the version is supported .
