Java重命名一堆文件并将其移动到新文件夹

Question

So here's the case.

I have one root folder that contains more folders and each of that folders have bunch of files. Those files are formatted '.srt' and '.mp4'. Because of some particular reasons I added numbers at the end of the file when I started downloading those files from the server. For example, 'Intro.srt - 1.1' and 'blabla720.mp4 - 1.1'. And the numbers are increasing, 1.2, 1.3, 2.1, 2.2, 3.1, 3.2 etc.

First I want to do is to move the numbers to the front like '1.1 - Intro.srt'. I already manage how to do is by shifting the last characters to the right.

Now I want to rename these files to match the .srt with .mp4 and move them to a new folder. For example: I want to rename '1.1 - blabla720.mp4' into the matching numbers of the .srt file which in this case is '1.1 - Intro.srt' so later on it will be '1.1 - Intro.mp4'. Then move them to a new folder 'Stage 1'. And for the files that starts with the number 2 will be moved to a new dir 'Stage 2' etc.

I want to do this in Java and when I run the java file it will rename and move all the files inside that root dir. (I already know how to recursively trace the entire folders).

So I was thinking:

1. Traverse the .srt file
2. Get the numbers of that .srt file
3. Search for the matching numbers for the .mp4 file
4. Rename the .mp4
5. Move those 2 files into the directory depending on the first number
6. Loop back to no.1

How do I approach this, should I use regex?

Answer 1

I think that you should focus first on allocating the right .srt file to the right .mp4 file. regex won't help you there.

Answer 2

How about something simple like this (untested code):

//get all files into a single array
File[] allFiles = getAListOfAllFilesRecursively("rootFolder");

//sort the files by their path (File is Comparable)
Arrays.sort(allFiles);

for (int x = 0; x < allFiles.length(); x++) {
    //if x ends with .srt, rename x+1 (the .mp4) based on the name we parse from x
    //otherwise, rename x (the .mp4) based on the name we parse from x+1
    if (allFiles[x].getName().endsWith(".srt")) {
        String name = getNameFromFileName(allFiles[x].getName());
        renameFileToName(allFiles[x+1], name);
    } else {
        String name = getNameFromFileName(allFiles[x+1].getName());
        renameFileToName(allFiles[x], name);
    }
}

You will probably want to add some checks here and there (you may want to verify the the number prefixes indeed match before renaming, in case you have a .srt file without a matching .mp4).

getAListOfAllFilesRecursively(String rootFolder) needs to return an array of File objects you retrieve recursively like you mentioned. getNameFromFileName(File file) needs to parse 1.1 - SomeName.srt into SomeName . renameFileToName(File file, String name) needs to rename the passed in file with a filename like 1.1 - abcd.mp4 to 1.1 - SomeName.mp4 given a value of SomeName for the name parameter (man, there are a lot of name-s :))).