File Name Not Able to Change

Question

I am looking for a way to convert my old file to a new file after my program processes the file. The new file should contain the current timestamp after it's been processed. For example, my old file is test.txt. After it's been processed, it should change to test2017-10-13.txt. I have searched for the solution around internet, but I still can't make it work. Here is my current source code

LocalDate now2 = LocalDate.now(); 
System.out.println("The current day is :" +now2);
File oldFile1 = new File("C:\\Users\\user\\Desktop\\test.txt");
File newFile1 = new File("C:\\Users\\user\\Desktop\\test"+now2+".txt");
boolean success = oldFile1.renameTo(newFile1);
System.out.println(success);

This is my sample output

The current day is :2017-10-13
false

Is it a known bug with java? I found this information online. Is there any method to do it without copying out the contents from the older file and writing it into the new file ?

no, you should call `file.exists()` to see. If it is not existed, the `rename` will return false — Viet, Oct 13 '17 at 03:18
`renameTo` doesn't generate a `IOException`, it just returns `true`/`false` depending on the success of the operation — MadProgrammer, Oct 13 '17 at 03:20
Did you have test.txt opened? (The program still running, not calling `close`.) — Joop Eggen, Oct 13 '17 at 03:36

score 0 · Answer 1 · answered Oct 13 '17 at 03:36

0

One common reason it return false is because your file is locked that's why it return false. Check if you open it in any application OR if your application itself locking it somewhere.

You can check Check if a file is locked in Java

answered Oct 13 '17 at 03:36

leafy

156
1
8

this is very possible reason. use file.setReadable() And file.setWritable while creating files. – Anshu kumar Oct 13 '17 at 07:59
note: writable in window is only changing the "Read Only" flag so it won't affect the file renaming. – leafy Oct 13 '17 at 11:04

score 0 · Answer 2 · answered Oct 13 '17 at 03:56

0

Try this...

DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        File file = new File("D:\\test\\test1.txt");
        File newFile = new File("D:\\test\\test"+dateFormat.format(cal.getTime())+".txt");
        if(file.renameTo(newFile)){
            System.out.println("File rename success");;
        }else{
            System.out.println("File rename failed");
        }

answered Oct 13 '17 at 03:56

Chandrakant

11
2

do it applicable for csv file as well ? – test Oct 13 '17 at 06:27
Yes it should, but you need to make changes in above code accordingly. – Chandrakant Oct 22 '17 at 09:20

score 0 · Answer 3 · answered Oct 13 '17 at 04:23

The best practice is, to check the file exists or not first. Then, perform IO operation.

    if (oldFile1.exists()) {
        boolean success = oldFile1.renameTo(newFile1);
        System.out.println(success);
    }
    else
    {
         System.out.println("failed");
    }

I'm assuming, the path, which you were using there user is just place holder and when you are running below code then you are changing it to your actual user name.

C:\\Users\\user\\Desktop\\test

score 0 · Answer 4 · answered Oct 13 '17 at 07:50

0

You need to set your file readable/writable. Sometime your file has read only access.

Second thing, You Should close streams (if used).

Try this:

               File f;
               f=new File("zzzz.txt");
               LocalDate ld=LocalDate.now();

               f.renameTo(new File("Hello "+ld.toString()+".txt"));
               System.out.println(f.getAbsoluteFile()+"  "+f.exists());

Out put is: Hello 2017-10-12.txt

answered Oct 13 '17 at 07:50

Anshu kumar

407
5
5

a file zzzz.txt exist and to rename this I used a temp file here. – Anshu kumar Oct 13 '17 at 07:52
Applicable for any kind of file including csv files. – Anshu kumar Oct 13 '17 at 08:02

File Name Not Able to Change

4 Answers4