Preserving recursive directory structure in zips with Java 8 - recursion

Question

I have the following directory on my laptop:
/tmp/
myapp/
assets/
config.yml
models/
troll.ply
tree.ply
textures/
troll-skin.png
tree-skin.png
I would like to zip /tmp/myapp/assets (and all its recursive contents) up into a ZIP named assets.zip, such that, when I unzip it (via unzip assets.zip), it preserves the directory structure under the assets folder. Hence, when unzipped, it would show config.yml in the "root" of the ZIP, and 2 directories inside the ZIP (models and textures). The rest of the files would be inside these respective subdirectories, etc.
When I run this code:
File sourceDir = new File("/tmp/myapp/assets");
ZipOutputStream zip = new ZipOutputStream(new FileOutputStream("/Users/myuser/archives/assets.zip"));
File[] contents = sourceDir.listFiles();
for(File file : contents) {
zip.putNextEntry(new ZipEntry(file.name));
InputStream isteam = new FileInputStream(file);
Files.copy(isteam, zip);
zip.closeEntry();
isteam.close();
}
zip.close();
The code correctly creates a ZIP at /Users/myuser/archives/assets.zip.
However, when I unzip it (unzip /Users/myuser/archives/assets.zip) and then run ls -al /Users/myuser/archives, my output is:
-rw-r--r-- 1 myuser 1754083733 492 Dec 30 14:14 assets.zip
-rw-r--r-- 1 myuser 1754083733 10 Dec 30 14:14 config.yml
-rw-r--r-- 1 myuser 1754083733 7 Dec 30 14:14 models
-rw-r--r-- 1 myuser 1754083733 9 Dec 30 14:14 textures
So both models and textures are being treated like files (not as directories). Furthermore, when I take a peek at the contents of the "models file", it appears that the contents of troll.ply and tree.ply have been concatenated inside of it, and ditto for the "tree file" with the 2 PNGs.
How can I tweak this so that directory structure (no matter how deep/nested) is always preserved in the resultant ZIP?

Answer 1

you can probably use the recursive method call to preserve the sub directories structure:
private static void addDir(File sourceDir, ZipOutputStream zip) throws IOException {
File[] contents = sourceDir.listFiles();
for(File file : contents) {
if(file.isDirectory()){
addDir(file, zip);
} else {
zip.putNextEntry(new ZipEntry(file.getAbsolutePath().replace("/tmp/myapp/","")));
System.out.println("file name " + file.getAbsolutePath().replace("/tmp/myapp/",""));
Path rn_demo = Paths.get(String.valueOf(file));
Files.copy(rn_demo, zip);
}
}
zip.closeEntry();
}
and you call in main method as below:
public static void main(String[] args) throws IOException {
File sourceDir = new File("/tmp/myapp/assets");
ZipOutputStream zip = new ZipOutputStream(new FileOutputStream("/Users/myuser/archives/assets.zip"));
addDir(sourceDir, zip);
zip.close();
}

Answer 2

Zipping through Java Zip seems to work differently on different OS's. I had the issue that it was working fine on Windows 7. But on Linux (RHEL6) the files were before the folders. This caused tests to fail.
A way to solve it is to sort the files and folders. folders first and then files. So the..
File[] contents = sourceDir.listFiles();
...File array should be sorted via path. Create a List<> from the Files and sort.
Collections.sort(newFiles, (a, b) ->
b.getAbsolutePath().compareTo(a.getAbsolutePath())
);
Note, I created an InputFile object to store the absolute path of the file.