Support for jrt-fs.jar in JDK 7 would be very helpful in allowing FindBugs to run under Java 9

[Bill Pugh]

Following up on a email thread started by Dalibor Topic…

In short, back porting jrt-fs.jar to work under Java 7 would be very helpful to the FindBugs project.

At length:

FindBugs needs access to the classifies for the standard Java libraries in order to analyze code. Right now, we access that through the file system, but that won’t be possible under jigsaw and JEP 220: Modular Run-Time Images. 

The JRL file system is what is recommended and needed to support FindBugs access to standard library classifies under Java 9. Having to support two different mechanisms for accessing standard library classifies would be annoying. We could move entirely over to the JRL file system. However, FindBugs is committed to running under Java 7 for a long time, at least several more years, and it would be good if FindBugs support for Java 9 were available within a year, if not sooner. 

So, if  jrt-fs.jar ran under Java 7, we could just rewrite that section of FindBugs to use the JRL file system, and have one version of the code running for Java 7+. 

Bill