How to check file existence and rename file with little modification

[Basit56]

Hi,
Hope you all will be fine. I want to ask i created a file named msg0000.wav in a directory named 220. Now i want to check if msg0000.wav already exist in the director then make a new file but with name msg0001.wav in the same directory and after reaching to number 9(msg0009.wav) it becomes msg0010.wav, msg0011.wav and so on. Means each time it check file exist or not and if file exist then simply change the number as i mentioned above.

Please guide me how can i do it. Checking file is easy i know it is do by a method "exist()" like file.exist() but how can i implement this logic that increment number each time if file exist.

Thank you.

[RamyaSivakanth]

/*Please go thru the code sample*/

import java.io.*;
class  Test
{
	public static void main(String[] args) throws Exception 
	{
                       //Initially file trial.txt is there in the directory
		File f = new File("trial.txt");
		int i=0;
                         
		while( i < 6)
		{
			if(f.exists())
			{
				f = new File("trial"+i);
				f.createNewFile();
				i++;
				
			}
		}//while
	}//main
}//Test

[gcampton]

i think you meant to put:

if(! f.exists())

[Tolls]

Substring the pre-. filename (msg0001) so you grab the last 4 characters, and turn that into an int. Increment that int. String.format() that against a format which will insert a padded number inbetween msg and .wav.

Of course, this will involve reading every filename in the directory to find the largest id. Better would be to keep track of the last used id (or the next id, possibly) and completely skip the substringing part.

[bbarclay]

How do you do this with a directory though. So if the directory "folder name" already exists then create a new folder and incriment the name as such. Folder. Folder_1. Folder_2

[Tolls]

Um, exactly the same logic?