Fwd: resource location problem in JDK 9 from build 148 onward

Rick Hillegas rick.hillegas at gmail.com
Tue Jan 17 00:55:31 UTC 2017


Resending since the moderator rejected my initial post for want of a 
subscription to jigsaw-dev.

-------- Original Message --------
Subject: 	resource location problem in JDK 9 from build 148 onward
Date: 	Mon, 16 Jan 2017 08:45:23 -0800
From: 	Rick Hillegas <rick.hillegas at gmail.com>
To: 	jigsaw-dev at openjdk.java.net, "derby-dev at db.apache.org" 
<derby-dev at db.apache.org>



Dalibor Topic suggested that I pose this question to the jigsaw-dev list:

Starting (at least) with build 148, resource location has changed in a
way which is not backward compatible with JDK 8. The following
experiment shows the behavior change:

1) Compile the following class using JDK 8 and put it in a jar file
called z.jar:

public class public class ResourceLocationProblem
{
   public static void main(String... args) throws Exception
   {
     String resourceName = "/META-INF/MANIFEST.MF";
     Class dummyClass = (new Object()).getClass();
     Object is = dummyClass.getResourceAsStream(resourceName);

     if (is != null) { System.out.println("Resource found."); }
     else { System.out.println("Resource NOT found!"); }
   }
}

2) Then run the program thusly:

   java -cp z.jar ResourceLocationProblem

On JDK 8, the program produces this output...

Resource found.

...while on JDK 9 build 151 the program produces this output...

Resource NOT found!

Dalibor pointed me to the following proposal, which indicates that some
significant changes have been made to resource location:
http://mail.openjdk.java.net/pipermail/jpms-spec-experts/2016-September/000392.html
However, I am not trying to use any jigsaw features. This test program
suggests that JDK 9 will break many legacy applications.

1) Is the observed behavior change a bug?

2) What is the recommended workaround?

Thanks,
-Rick



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