Read directly a file within a Zip file - Java

Question

My situation is that I have a zip file that contains some files (txt, png, ...) and I want to read it directly by their names, I have tested the following code but no result

Answer 1

If you can be sure that your zip file will never be packed inside another jar, you can use something like:

URL zipUrl = Main.class.getResource("/resources/zipfile.zip");
URL entryUrl = new URL("jar:" + zipUrl + "!/test.txt");
InputStream is = entryUrl.openStream();

Or:

URL zipUrl = Main.class.getResource("/resources/zipfile.zip");
File zipFile = new File(zipUrl.toURI());
ZipFile zip = new ZipFile(zipFile);
InputStream is = zip.getInputStream(zip.getEntry("test.txt"));

Otherwise, your choices are:

• Use a ZipInputStream to scan through the zip file once for each entry that you need to load. This may be slow if you have a lot of resources, unless you can reuse the same ZipInputStream for all your resources.
• Don't pack the resources in a nested zip file, and just inline them in the jar with the code.
• Copy the nested zip file into a temporary directory, and access it using the ZipFile class.