How to list the files inside a JAR file?

Question

I have this code which reads all the files from a directory.

    File textFolder = new File(\"text_directory\");

    File [] texFiles = textFolder.listFiles         


        

Answer 1

The most robust mechanism for listing all resources in the classpath is currently to use this pattern with ClassGraph, because it handles the widest possible array of classpath specification mechanisms, including the new JPMS module system. (I am the author of ClassGraph.)

How to know the name of the JAR file where my main class lives?

URI mainClasspathElementURI;
try (ScanResult scanResult = new ClassGraph().whitelistPackages("x.y.z")
        .enableClassInfo().scan()) {
    mainClasspathElementURI =
            scanResult.getClassInfo("x.y.z.MainClass").getClasspathElementURI();
}

How can I read the contents of a directory in a similar fashion within a JAR file?

List classpathElementResourcePaths;
try (ScanResult scanResult = new ClassGraph().overrideClasspath(mainClasspathElementURI)
        .scan()) {
    classpathElementResourcePaths = scanResult.getAllResources().getPaths();
}

There are lots of other ways to deal with resources too.