renameTo alternative?

arleitiss

Hey, I got a problem,I made a program using java which takes russian named files and renames them into english. But the problem is: When it comes to a loop renaming say 50 (for example) files, it only renames 25 of them. Then if I try again it renames 12 of them. Then 6. then 3 etc..

Any alternatives?

public void Rename(String name, File which){
        which.renameTo(new File(desti+"\\"+name)); 
    }

This function is called by loop which should rename all files.

PrzemoF

The most important part for debugging is missing: the loop.

im invisible

who spiked the hamsters water?

Tar.Aldarion

I think it's some sort of loop joke :pac:

im invisible

it wasn't the only thread in the last 10 minutes to have the same post multiple times
.
.
it wasn't the only thread in the last 10 minutes to have the same post multiple times

etc.

arleitiss

So any solutions?

PrzemoF

<multiple post mode off>

Show us the loop

arleitiss

PrzemoF wrote: »

<multiple post mode off>

Show us the loop

        for(int a = 0; a < ch.length(); a++){
           String newName = "";
            for(int i = 0; i < ch.getNumber()[a].length(); i++){
                char letter = ch.getNumber()[a].charAt(i);
                String let = Character.toString(letter);
                newName = newName+= ru.toEng(let);
            }
            ou.Rename(newName, ch.getFile(a));
        }

PrzemoF

How do you set "ch"?
"ch.length()" equals the number of files for renaming?
What happens if you replace ch.length() with a fixed number - does it work OK then?

arleitiss

PrzemoF wrote: »

How do you set "ch"?
"ch.length()" equals the number of files for renaming?
What happens if you replace ch.length() with a fixed number - does it work OK then?

ch.length is correct, I tried outputting it to console and it displayed number of file okay

BrokenArrows

arleitiss wrote: »

ch.length is correct, I tried outputting it to console and it displayed number of file okay

If ch.length is correct then where is it stopping.
Do a console output of the value of ch.length and the value of a after each loop and see where its breaking.

arleitiss

BrokenArrows wrote: »

If ch.length is correct then where is it stopping.
Do a console output of the value of ch.length and the value of a after each loop and see where its breaking.

As I said: if I leave the renameTo line in, it stops half way. So if ch.length is 50, it will stop at 25. If I take out renameTo function ti goes all the way through no problem.

BrokenArrows

arleitiss wrote: »

As I said: if I leave the renameTo line in, it stops half way. So if ch.length is 50, it will stop at 25. If I take out renameTo function ti goes all the way through no problem.

Loops don't just stop so there must be an exception happening somewhere in your rename.

Are you trapping any exceptions?

Sherfin

Not done Java in a while so not 100% sure if this is the problem but..
Does it just rename every 2nd file?
If so, the list may be changing for each loop.

e.g. List is FileA, FileB, FileC, FileD

1st pass int a=0 So it changes file[0] FileA to NewFileA
List has now changed to FileB, FileC, FileD as FileA no longer exists
2nd pass a=1 so it changes file[1] FileC to NewFileC (FileB is at position [0] now)
List now comprises of FileB, FileD
On the 3rd pass int a =2 which is the length of the list and the loop ends

Hope this makes sense. To prove/disprove this, you could output the length on each pass to see if it is decreasing.

arleitiss

Yeah it skips every 2nd file. So skips 1. ALso I don't throw any exceptions.

Sherfin

Then it could very well be what I tried to explain above.
If so, a list with an odd number of items will throw an exception (OutOfBounds I think ?) when it reaches halfway (or halfway +1)


There is a way around this problem

Try looping backwards. i.e. for(int a =ch.length(); a >0; a--)

arleitiss

Sherfin wrote: »

Then it could very well be what I tried to explain above.
If so, a list with an odd number of items will throw an exception (OutOfBounds I think ?) when it reaches halfway (or halfway +1)


There is a way around this problem

Try looping backwards. i.e. for(int a =ch.length(); a >0; a--)

Didn't work, it said:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException

Sherfin

Sorry, as I said it's been a while since I did any java.
If this happens at the first pass in the loop then try for(int a =ch.length()-1; a >0; a--)

arleitiss

Sherfin wrote: »

Sorry, as I said it's been a while since I did any java.
If this happens at the first pass in the loop then try for(int a =ch.length()-1; a >0; a--)

Ohh nice one sir, that worked except for 1 problem, but I can fix it myself. It misses 1 file but it's not big of a deal, it's just a matter of writing a > -1 (I think) but yeah it works, oh my god never thought of loops being used in reverse. Thank you very much.
Yep a > -1 did that.
I don't see the logic or difference behind this, but as people say sometimes: if it works, don't touch it.

Sherfin

Glad to help.
It probably should be a>=0

The problem is that the list of files is changing every time you loop.
There were 50 items (filenames) in your original list
Each time you changed an item, it was no longer in the list.
As 'int a' counted up, the list got shorter by one.
(when a=0 length =50, a=1 length =49 ........ a=25 length =25)
This is why it kept stopping halfway.
By counting backwards it didn't matter that the list was getting shorter
(when a=50 length =50, a=49 length =49 ........ a=1 length =1)

arleitiss

Sherfin wrote: »

Glad to help.
It probably should be a>=0

The problem is that the list of files is changing every time you loop.
There were 50 items (filenames) in your original list
Each time you changed an item, it was no longer in the list.
As 'int a' counted up, the list got shorter by one.
(when a=0 length =50, a=1 length =49 ........ a=25 length =25)
This is why it kept stopping halfway.
By counting backwards it didn't matter that the list was getting shorter
(when a=50 length =50, a=49 length =49 ........ a=1 length =1)

ohh I see, well thanks, thats solved.