Fat jar has two candidate URLs for `classpath*:**/` patterns, leading to resources duplication

[snicoll]

This is a follow-up of SPR-14934.

Assume we need to collect the resources matching the classpath*:/**/*.xml pattern in a Spring Boot application. As of 1.4, two root urls will be used for the search:

jar:file:/Users/foo/SPR-13685/target/SPR-13685-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
jar:file:/Users/foo/SPR-13685/target/SPR-13685-0.0.1-SNAPSHOT.jar!/

The former is the one used by the LaunchedUrlClassLoader and the latter is used by the system classloader. Because we asked to search "everything", the system classloader finds the resource again, leading to a duplication. Arguably, the system classloader must ignore anything in BOOT-INF since it is managed by the LaunchedUrlClassLoader already.

[philwebb]

@wilkinsona will be interested in this one. I hope we don't need to add filtering back to the system classloader.

[kazuki43zoo]

@wilkinsona @snicoll

I tried spring boot 1.4.3 and spring 4.3.5 snapshot version, however this issue and SPR-14934 does not resolved in my repro project.

In my repro project is https://github.com/kazuki43zoo/repro-PathMatchingResourcePatternResolver.

$ ./mvnw -U clean package
$ $ java -jar target/path-demo-0.0.1-SNAPSHOT.jar
...
------resources1---------
jar:file:/Users/xxx/git/repro-PathMatchingResourcePatternResolver/target/path-demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/my/mappers/BarMapper.xml
jar:file:/Users/xxx/git/repro-PathMatchingResourcePatternResolver/target/path-demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/my/mappers/FooMapper.xml
jar:file:target/path-demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes/my/mappers/BarMapper.xml
jar:file:target/path-demo-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes/my/mappers/FooMapper.xml
...

It has been detected same resource twice from relative path and absolute path.

[snicoll]

@kazuki43zoo I am not sure the framework fix has been backported yet. @jhoeller any idea here?

[kazuki43zoo]

@snicoll Oh... I will confirm it.

[wilkinsona]

It hasn't: https://github.com/spring-projects/spring-framework/commits/4.3.x/spring-core/src/main/java/org/springframework/core/io/support/PathMatchingResourcePatternResolver.java

[kazuki43zoo]

@snicoll @wilkinsona , thanks for quick replying !! I will try again after backporting to Spring 4.3.x line.
Thanks.

[kazuki43zoo]

Hi @snicoll @wilkinsona @jhoeller, I've tried latest snapshot version. This issue has been resolved !!

[wilkinsona]

@kazuki43zoo Thanks for the confirmation