Deleting data from text files

Question

Hi there,
I am having a real battle trying to delete data from a text file I am using. There seems to be this giant cloud with Java, where there is no real easy way to delete text from a file??
I have a JFrame with two textfields on it where you enter the username and pcname. There is a OK button once you have entered those details.
On action event I would like those two details, to be removed from the text file that has been read in.
I have a text file like this:
bob
pc1
bill
pc2
The data above gets written no problem, one at at a time using the below.
File f = new File("\\c:\\filename.txt");
String strToWrite;
try
FileOutputStream fstr = new FileOutputStream(f);
strToWrite = username1+ '\r'+'\n' ;
byte[] bytes = strToWrite.getBytes(); fstr.write(bytes);
strToWrite = pcname1 + '\r'+'\n' ;
byte[] bytes2 = strToWrite.getBytes(); fstr.write(bytes2);
strToWrite = username2+ '\r' +'\n' ;
byte[] bytes3 = strToWrite.getBytes(); fstr.write(bytes3);
strToWrite = pcname2 + '\r'+'\n' ;
byte[] bytes4 = strToWrite.getBytes(); fstr.write(bytes4);
catch (IOException e)
System.out.println("Error -- " + e.toString());
To read them back in I have made the follwoing:
BufferedReader br= null;
Count = 0;
try
br = new BufferedReader(new InputStreamReader(new FileInputStream("\\c:\\filename.txt")));
String s = "";
while((s=br.readLine()) != null )
Count = 1;     
     //System.out.println("Data is " + s);
     inboundtext = s;
     if ( Count == 1 )
break;
while((s=br.readLine()) != null )
//System.out.println("Data is " + s);
inboundtext = s;
Count = 2;
if ( Count == 2 )
break;
catch(IOException ie)
finally
try
     if(br!=null) br.close();
catch(Exception e)
Now the above I know, is reading each line of the text file one at a time.
Now what I would like is that when the text that we got from the textfields, using getText(), be removed from the file without destroying the rest of the records in there? Why is it so easy to add and replace files, but not do any deleting from them?
please help!!

Answer 1

sorry, FileOutputStream fstr = new FileOutputStream(f);
should be FileOutputStream fstr = new FileOutputStream(f, true);