not able to delete file

[adeeb alexander]

Hi all. I am trying to do some operation on file. In which a file is written in other file leaving some line. Then that new file is renamed to older file. But that is not happening with ma code. can any one find where i went wrong. The code is below

  try{
			int ct=0;
			for(int i=0;i<colVal.size();i++)
					{
						System.out.println("I is:"+i);
						ct=0;
						File tabCol = new File(path+colVal.get(i));
						System.out.println(colVal.get(i));
						File f = new File(path+"Bkp");
						f.createNewFile();
						f.canRead();
						f.canWrite();
						BufferedReader readCol = new BufferedReader(new FileReader(tabCol));
						BufferedWriter colWrite = new BufferedWriter(new FileWriter(f));
						while((str=readCol.readLine())!=null)
						{
								if(lineNum.contains(ct))
								{
									System.out.println("Skipped at:"+ct);
								}
								else
								{
									colWrite.write(str+newline);
									colWrite.flush();
									System.out.println("written at:"+ct);
								}
							ct++;
						}
						readCol.close();
						colWrite.close();
						tabCol.delete();
						f.renameTo(tabCol);
					}
			}catch(Exception ce){
				System.out.println("Delete:"+ce);
			} 

Thanks and Regards
Adeeb
>

[Greg Charles]

It's certainly possible that the OS, security manager, or something else is preventing you from deleting the file. You should be looking at the boolean return values from the various calls you make. File.delete(), for example, returns false if the file can't be deleted, so your exception handler won't catch it. A couple of the calls, f.canRead() and f.canWrite(), don't do anything except return a boolean, so if you're not looking at the return value, there's no point to even making the call.

Take a look at the java.io.File API for more information.

[James Sabre]

If after taking Greg's advice you find that you do have permission to delete the file then it might be worth doing a System.gc() just prior to doing the delete(). I know I know I know - one never needs to invoke System.gc() and few believe that this can have an effect but what can it cost to try it.