FileReader and FileWriter

[divya madala]

The below code doesn't work. Is there anyway how I can read only a particular line in a file and rewrite only that line?

 
  File fileName = new File(DataFolder + p + "Wis_CV_DailyProcessIni.dat");
  FileWriter fw = new FileWriter(fileName);
  if (fileName.exists()) {
 FileReader fr = new FileReader(fileName);
 BufferedReader br = new BufferedReader(fr);
 String line;
  while ( (line = br.readLine()) != null) {
 if (line.indexOf("CAAta") >= 0)
  fw.write("CAAta=" + getCaseidAt1() +
   System.getProperty("line.separator")); 
}
}

[ May 03, 2004: Message edited by: divya madala ]
[ May 03, 2004: Message edited by: divya madala ]
[ May 03, 2004: Message edited by: divya madala ]

[Joe Ess]

java.io.RandomAccessFile

[Stan James]

RandomAcessFile will read or write content in the middle of a file, but it can only replace content of exactly the same length. If you try to replace "hello" with "goodbye" you'll clobber the next couple bytes of whatever followed. You cannot insert or delete content in the middle of a file ... it's just a limitation of the file system. (Some operating systems understand line-oriented files and support such actions.) You're pretty much stuck with reading the whole file, making changes and writing a new file. Such is life.