perwendel/spark · error · FileNotFoundException

Resource location [ ] is neither a URL not a well-formed…

Error message

Resource location [${resourceLocation}] is neither a URL not a well-formed file path

What it means

ResourceUtils.getURL first tries to interpret the location string as a URL; on MalformedURLException it falls back to treating it as a file path. If both conversions fail — the string is neither a well-formed URL nor a usable file path — it throws FileNotFoundException stating the resource location is 'neither a URL not a well-formed file path'.

Solutions

Fix the location string: either a full valid URL (e.g. http://..., file:/absolute/path) or a valid file path.
Encode special characters (spaces -> %20) or drop an invalid scheme and pass the plain absolute file path.
On Windows use forward slashes or the file:/// form with proper drive-letter syntax (file:/C:/temp/x.txt).
Validate the location with new URL(...) or new File(...).toURI().toURL() in a test before wiring it into config.

Example fix

// before
URL url = ResourceUtils.getURL("file://C:\\temp\\my file.txt"); // malformed

// after
URL url = ResourceUtils.getURL("file:/C:/temp/my%20file.txt");

Defensive patterns

Strategy: validation

Validate before calling

try {
    new URL(location);
} catch (MalformedURLException e) {
    try { new File(location).toURI().toURL(); } catch (MalformedURLException e2) {
        throw new IllegalStateException("Location is neither URL nor valid file path: " + location);
    }
}

Try / catch

try {
    URL url = ResourceUtils.getURL(location);
} catch (FileNotFoundException e) {
    log.error("Malformed resource location: {}", location);
}

Prevention

Encode spaces and special characters in paths (%20).
On Windows prefer forward slashes and proper file:/ URLs.
Validate configured locations at startup with a fail-fast check.

When it happens

Trigger: Calling getURL with a malformed string such as "htp:/bad", "file://C:temp" (invalid for toURI().toURL()), a string with illegal URI characters (spaces/control chars not encoded), or a location with a wrong scheme prefix that is neither classpath:, http(s), nor a valid path.

Common situations: Windows paths with backslashes or drive letters combined with a file:// prefix the URI parser rejects; unencoded spaces in file paths; config values concatenated incorrectly producing invalid URLs; typos in protocol names.

Understand the failure class

Background: "Invalid URL" errors: why new URL(), URI.parse, and reqwest::Url reject your string — missing scheme, whitespace, and bad path format — this error's family across 39 libraries.

Related errors

AI-assisted analysis of perwendel/spark@1973e402f5 (2026-09-10). Data as JSON: /api/errors/91faee341203adb5. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/spark/utils/ResourceUtils.java:145

        if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
            String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());
            URL url = ClassUtils.getDefaultClassLoader().getResource(path);
            if (url == null) {
                String description = "class path resource [" + path + "]";
                throw new FileNotFoundException(
                        description + " cannot be resolved to URL because it does not exist");
            }
            return url;
        }
        try {
            // try URL
            return new URL(resourceLocation);
        } catch (MalformedURLException ex) {
            // no URL -> treat as file path
            try {
                return new File(resourceLocation).toURI().toURL();
            } catch (MalformedURLException ex2) {
                throw new FileNotFoundException("Resource location [" + resourceLocation +
                                                        "] is neither a URL not a well-formed file path");
            }
        }
    }

    /**
     * Resolve the given resource location to a {@code java.io.File},
     * i.e. to a file in the file system.
     * <p>Does not check whether the file actually exists; simply returns
     * the File that the given location would correspond to.
     *
     * @param resourceLocation the resource location to resolve: either a
     *                         "classpath:" pseudo URL, a "file:" URL, or a plain file path
     * @return a corresponding File object
     * @throws FileNotFoundException if the resource cannot be resolved to
     *                               a file in the file system
     */
    public static File getFile(String resourceLocation) throws FileNotFoundException {

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