Need help with strange Class#getResource() issue

Question

I have some legacy code that reads a configuration file from an existing jar, like:

URL url = SomeClass.class.getResource(\"/configuration.properties\");
//          


        

Answer 1

There are bugs in several Java versions when using file URLs containing spaces. "/path/to/jar" is probably not your real path, so I at least assume that this is what you're running into. Your code is at least in theory ok.

Answer 2

A typical implementation of ClassLoader.getResourceAsStream is:

public InputStream getResourceAsStream(String name) {
    URL url = getResource(name);
    try {
        return url != null ? url.openStream() : null;
    } catch (IOException e) {
        return null;
    }
}

Class.getResource and getResourceAsStream behave the same as each other.

So it looks like either you are using a strange and broken subclass of ClassLoader, or there is some mistake in the tests on your side.

Answer 3

It works with getresourceasstream because it is in the classpath, but it doesn't work with the URL maybe because the URL is not ok.

I don't know if the URL that getResource is creating is not ok, or there isn't a correct handler for the protocol (wouldn't it be file:jar:c:/myjar.jar!configuration.properties or something by the like (with two colons?)

Answer 4

use urlConnection.setUseCaches(false), since it's an ant task, it's likely not to be forked in a separate process. The URLs cache the files (or the JarFile in that case)... if the files is change due to the build, you get quite a similar behavior.

you may want to close the modified jar files meanwhile useCaches(true), JarURLConnection.getJarFile().close()

Sometime I wish handling of Jar/Zip was a little better

cheers