Spring Be more defensive in UrlResource about cleaning the path [SPR-17198]

Dave Syer opened SPR-17198 and commented

This method from UrlResource throws UnsupportedFeatureError in GraalVM:

private URL getCleanedUrl(URL originalUrl, String originalPath) {
     try {
          return new URL(StringUtils.cleanPath(originalPath));
     }
     catch (MalformedURLException ex) {
          // Cleaned URL path cannot be converted to URL
          // -> take original URL.
          return originalUrl;
     }
}

So the originalUrl would have been fine, but it cannot get past this private method to read the input stream. We could be more defensive there.

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Affects: 5.0.8

Reference URL: https://github.com/oracle/graal/issues/623

Issue Links: - #21529 Initial GraalVM native images (Substrate VM) support ("is depended on by") - #19974 UrlResource getFilename should not contain query parameters

Comment From: spring-projects-issues

Dave Syer commented

PR: https://github.com/spring-projects/spring-framework/pull/1936 (verified to work with Graal AOT).

Comment From: spring-projects-issues

Juergen Hoeller commented

A straightforward refinement for a start is to only create a new URL instance if the cleaned path actually differs from the original path. This should cover most internal use of UrlResource and avoid common Graal issues with it that way.

Comment From: spring-projects-issues

Dave Syer commented

That would also work. I can change the PR if you want.

Comment From: spring-projects-issues

Juergen Hoeller commented

Ha, seems we posted at exactly the same time there ;-) Got the change locally working already, let's see how far we get with it (to be pushed ASAP)... I quite like it as a general optimization, avoiding the repeated URL parsing effort. I was experimenting with handling the cleaned path as a String but unfortunately that causes some regressions due to special handling in URL.equals, so the "original URL as far as possible" approach sounds like the best compromise.