ServletContextResourceLoader performance problem: creates a lot of MalformedURLExceptions ("no protocol") in normal operation [SPR-8283]

[spring-projects-issues]

Lari Hotari opened SPR-8283 and commented

The performance of ServletContextResourceLoader.getResource is very bad because it creates a MalformedURLException in normal operation.
I've noticed this problem in Grails webapplications.

Creating exceptions are costly because filling the stack trace of the exception takes relatively a lot of cpu.

There should be a better way to check url validity (without exceptions). In commons-validator there is org.apache.commons.validator.routines.UrlValidator , but I guess a simple check in ServletContextResourceLoader.getResource should be ok. (if path starts with '/' , prefer getResourceByPath)

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Affects: 3.0.5

Referenced from: commits f388408

[spring-projects-issues]

Lari Hotari commented

pinging this issue. It's still a minor performance problem. http://shipilev.net/blog/2014/exceptional-performance/ tells why.

[spring-projects-issues]

Juergen Hoeller commented

Good point. I've added a

if (location.startsWith("/")) {
    return getResourceByPath(location);
}

block to the very beginning of DefaultResourceLoader's getResource implementation, optimizing for such non-URL paths. We still fall back to getResourceByPath after a URL parsing failure as well, but that's an exceptional case then and not used for regular "/..." paths anymore.

Juergen