Load Spring Boot Classes in ClassLoader

Question

I need to read a Spring Boot jar and load all the clases on a ClassLoader.

My problem,in spring boot classes are on "/BOOT-INF/classes" directory and not on the root directory.

Anybody knows how i can load this classes in my ClassLoader?

I try to do this:

private URLClassLoader getURLClassLoaderFromJar(Path jarPath) throws MalformedURLException {
        return URLClassLoader
                .newInstance(new URL[] { new URL("jar:file:" + jarPath.toAbsolutePath().toString() + "!/") });
}

This load the jar, but no the classes inside /BOOT-INF/classes

Answer 1

I finally opted for decompress de jar on a temporary directory and create a URLClassloader with this entries: One to the root directory. One to the BOOT-INF/classes And one for every jar in BOOT-INT/lib

Path warDirectory = decompressWar(absolutePathFile);

File rootDir = new File(warDirectory.toAbsolutePath().toString());
File springBootDir = new File(warDirectory.toAbsolutePath().toString() + "/BOOT-INF/classes/");

List<URL> listaURL = new ArrayList<URL>();
listaURL.add(rootDir.toURI().toURL());
listaURL.add(springBootDir.toURI().toURL());

//This scan the BOOT-INF/lib folder and return a List<URL> with all the libraries.
listaURL.addAll(getURLfromSpringBootJar(warDirectory));


URL[] urls = new URL[listaURL.size()];
urls = listaURL.toArray(urls);
cl = new URLClassLoader(urls);

//This explore the JAR and load all the .class fulies to get the className.
resultClassesBean = loadJars(Collections.singletonList(pathJarFile), cl);

if(resultClassesBean != null && resultClassesBean.getListResultClasses() != null && !resultClassesBean.getListResultClasses().isEmpty()) {
    for(String clazz : resultClassesBean.getListResultClasses()) {
        cl.loadClass(clazz);
    }
}