从OSGi捆绑包中启动类的主要方法

Question

I have a jar file, A.jar, that contains, among various library functions, a class with a main method, MainClass . This jar file is deployed by wrapping it into an OSGi bundle, B.jar, so that the library functions are available to other plugins within the OSGi container, as specified in B.jar's MANIFEST.MF.

I also want to be able to launch the MainClass.main method contained in A.jar in a separate process, outside OSGi, but all I have available on the file system is B.jar. So, for example,

java -cp B.jar MainClass

fails with

Error: Could not find or load main class MainClass

whereas

java -cp A.jar MainClass

works just fine on my desktop, before A.jar is wrapped up in B.jar.

Is there any way to run MainClass.main directly from B.jar?

Answer 1

It is not clear but I assume that B.jar contains A.jar as an entry. So A.jar is just a resource in B.jar. In order to run the MainClass in A.jar from B.jar, you will need to write a new main for B.jar that will create a ClassLoader for the A.jar resource and then load MainClass class and call its main method.