ClassLoader.getResources("") return different results, when run in ide/fat jar/exploded directory

[hengyunabc]

Print ClassLoader.getResources("") results in main method:

    public static void main(String[] args) throws IOException {
        Enumeration<URL> resources = Thread.currentThread().getContextClassLoader().getResources("");
        while(resources.hasMoreElements()) {
            System.err.println(resources.nextElement());
        }
        System.err.println("=====");

        SpringApplication.run(DemoApplication.class, args);
    }

• IDE:

file:/private/tmp/demo/target/classes/
=====

• Fat jar:

jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-starter-web-1.5.4.RELEASE.jar!/
jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-starter-1.5.4.RELEASE.jar!/
jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-1.5.4.RELEASE.jar!/
jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-autoconfigure-1.5.4.RELEASE.jar!/
jar:file:/private/tmp/demo/target/demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-starter-logging-1.5.4.RELEASE.jar!/
=====

• Exploded directory:

cd target
unzip demo-0.0.1-SNAPSHOT.jar -d test
cd test 
java org.springframework.boot.loader.PropertiesLauncher

file:/private/tmp/demo/target/test/
file:/private/tmp/demo/target/test/BOOT-INF/classes/
=====

[wilkinsona]

This is by design (see #7003). Is the current behaviour causing a problem?

[hengyunabc]

Some libraries depend on ClassLoader.getResources("") to scan annotations. When run in fat jar, it may scan excess classes.

There is no problem, I just have some doubts, thanks.