Getting the MANIFEST.MF from a dependency in the fat jar

[jarias]

Hi I'm using the Stormpath Java SDK as dependency in my spring-boot project and building the entire thing as a fat jar using the spring-boot gradle plugin, and it throws an exception trying get its manifest file.

java.lang.RuntimeException: Unable to obtain version from manifest path [jar:file:/Users/jarias/Code/jarias/tk/build/libs/tk-0.1.0.jar!/lib/stormpath-sdk-impl-0.8.1.jar!/META-INF/MANIFEST.MF]
    at com.stormpath.sdk.impl.http.support.Version.getManifest(Version.java:56)
    at com.stormpath.sdk.impl.http.support.Version.lookupClientVersion(Version.java:43)
    at com.stormpath.sdk.impl.http.support.Version.<clinit>(Version.java:28)
    at com.stormpath.sdk.impl.ds.DefaultDataStore.applyDefaultRequestHeaders(DefaultDataStore.java:593)

The code from Version.java looks like this:

    private static String lookupClientVersion() {
        Class clazz = Version.class;
        String className = clazz.getSimpleName() + ".class";
        String classPath = clazz.getResource(className).toString();
        if (!classPath.startsWith("jar")) {
            // Class not from JAR
            return "NOT-FROM-JAR";
        }
        String manifestPath = classPath.substring(0, classPath.lastIndexOf("!") + 1) + "/META-INF/MANIFEST.MF";
        Manifest manifest = getManifest(manifestPath);
        Attributes attr = manifest.getMainAttributes();
        String value = attr.getValue("Implementation-Version");
        if (value == null) {
            throw new IllegalStateException("Unable to obtain 'Implementation-Version' property from manifest.");
        }
        return value;
    }

    private static Manifest getManifest(String path) {
        try {
            return new Manifest(new URL(path).openStream());
        } catch (IOException e) {
            throw new RuntimeException("Unable to obtain version from manifest path [" + path + "]");
        }
    }

Is this something that can be done using the fat jar? What should code look like? And can it maintain compatibility when this lib is use in a non spring-boot fat jar?

If a fix is possible I'll pass it along to the Stormpath team.

By the way I got a similar issue with JBoss TS but it wasn't getting the manifest but a properties file thats inside the JBoss TS jar(s) my workaround in that case was to dup the prop file in my project.

[dsyer]

If people make assumptions about the structure of URLs for resources in the classpath there's not a lot we can do, and obviously throwing an exception in such code is really bad for users. If you want to try and get the Stormpath code changed, a more robust idiom for locating the version from the manifest is available in the JDK, and is used in Spring in a few places (e.g. here.

I'm sure the properties file will be a similar error, but if you can point us at the code that loads it we might be able to work around it (or not).

[jarias]

Thanks @dsyer I already pass the info to the Stormpath guys, turns out they already had a ticket for a similar issue but with jars build with the Maven Shade plugin.

I'm closing this ticket since it was more a general question rather an actual bug or feature for spring boot.

As for the JBoss TS issue that I also mention the file was arjuna-properties.xml but I haven't dig the source code to see how they try to fetch it, cause I end up just duplicating the file inside my project as a workaround.