The picture above shows a tool by the Luyten after the decompiled a jar package
Description:
SpringBoot bootstrap class is provided outermost in a package, such as the above org.springframework.boot.loader.
Code of the application is the need to put BOOT-INF / classes directory; a jar file and other applications that rely on the need to put the BOOT-INF / lib directory.
When the jar as standardalone program runs (not into container), SpringBoot Main-Class can be disposed in the generated META-INF / MANIFEST.MF inside into org.springframework.boot.loader.JarLauncher, JarLauncher creates a class own spring ClassLoader: LaunchedURLClassLoader, will be able to load the classloader BOOT-INF / lib inside the package depends above by its URL, and is defined by the inside reflection Manifest Start-class which class this class and invoke the main method which .