Get folder from Resources folder JAVA

Question

Hi everyone I can't figure out with this problem : this line of code should work

File[] file = (new File(getClass().getResource("resources/images_resultats"))).listFiles();

I want a list of File, these Files are under "images_resultats" under "resources".

Resources are not files, in most cases they are entries in a zip container (the jar file) and not be accessed or treated like files. It is very difficult to list the contents of an unknown jar file in this manner — MadProgrammer, Apr 14 '16 at 12:39
[For example](http://stackoverflow.com/questions/18758105/how-can-i-count-the-number-of-files-in-a-folder-within-a-jar/18758724#18758724), the second solution suggests using a "known" file/resource which contains a list of the resources names, which could be generated at build time — MadProgrammer, Apr 14 '16 at 12:43
If the directory is not included in the jar, you should be able to use a relative path directly — MadProgrammer, Apr 14 '16 at 12:45

Nicolas Filotto · Accepted Answer · 2016-04-14T12:59:57.410

3

It won't work if resources/images_resultats is not in your classpath and/or if it is in a jar file.

Your code is not even correct it should something like:

File[] file = (new File(getClass().getResource("/my/path").toURI())).listFiles();

edited Apr 14 '16 at 12:59

answered Apr 14 '16 at 12:39

Nicolas Filotto

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so I must have a folder containing my three folder `images_resultats` etc... and the `.jar` – Arnauld Alex Apr 14 '16 at 12:51
To get the relative paths use `list()` instead of `listFiles()`. – satk0 Feb 10 '23 at 17:07

Richard Tingle · Answer 2 · 2020-12-19T11:30:36.740

You can determine what files are in a folder in resources (even if its in a jar) using the FileSystem class.

public static void doSomethingWithResourcesFolder(String inResourcesPath) throws URISyntaxException {
    URI uri = ResourcesFolderUts.class.getResource(inResourcesPath).toURI();
    try( FileSystem fileSystem = FileSystems.newFileSystem(uri, Collections.emptyMap() ) ){
        Path folderRootPath = fileSystem.getPath(inResourcesPath);
        Stream<Path> walk = Files.walk(folderRootPath, 1);
        walk.forEach(childFileOrFolder -> {
            //do something with the childFileOrFolder
        });
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

inResourcesPath should be something like "/images_resultats"

Note that the childFileOrFolder paths can only be used while the FileSystem remains open, if you try to (for example) return the paths then use them later you've get a file system closed exception.

Change ResourcesFolderUts for one of your own classes

score -3 · Answer 3 · answered Apr 14 '16 at 12:54

-3

Assuming that resources folder is in classpath, this might work.

   String folder = getClass().getResource("images_resultats").getFile();
   File[] test = new File(folder).listFiles();

answered Apr 14 '16 at 12:54

s_u_f

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it return a `java.lang.NullPointerException` -> `String folder = getClass().getResource("images_resultats").getFile();` – Arnauld Alex Apr 14 '16 at 13:04
`getClass().getResource("images_resultats").getFile()` returns null whether folder is empty! – Sir Montes Aug 02 '21 at 12:45

Get folder from Resources folder JAVA

3 Answers3