apache/flink · error · RuntimeException

URL is invalid. This should not happen.

Error message

URL is invalid. This should not happen.

What it means

Thrown by PackagedProgram.getJobJarAndDependencies(URL, List<File>, boolean) when converting a temporary extracted library File to a URL via toURI().toURL() raises MalformedURLException. The message 'This should not happen' signals that this conversion is expected to always succeed for valid File instances; it is a defensive RuntimeException wrapper.

Solutions

1. Inspect the File path that failed (log extractedTempLibraries) for unusual characters or null components.
2. Ensure the system temp dir is writable, stable, and uses a conventional encoding (UTF-8).
3. If reproducible, report as a Flink bug — the conversion of a valid File to a URL is contractually expected to succeed.
4. Clear the Flink temp/extracted-libraries directory and retry the job submission.

// Defensive check before constructing URLs from extracted libraries
for (File f : extractedTempLibraries) {
    if (f == null || f.getAbsolutePath() == null) {
        throw new IllegalStateException("Extracted library file is null or has no absolute path");
    }
}

try {
    List<URL> urls = PackagedProgram.getJobJarAndDependencies(jarFile, extractedLibs, isPython);
} catch (RuntimeException re) {
    if (re.getMessage().contains("URL is invalid")) {
        // log the file list and the temp dir for diagnosis
    }
    throw re;
}

When it happens

Trigger: A File in extractedTempLibraries whose absolute path cannot be turned into a valid URL. In practice this only occurs if the file path contains characters that violate URL/URI encoding rules in an unusual way, or if the File object is in an inconsistent state.

Common situations: Extremely rare; typically indicates a corrupt temp directory, an exotic filesystem path, or a JVM/OS path-encoding edge case. Not user-facing under normal operation.

Related errors

• An I/O error occurred while creating temporary file to…
• Access to the main method was denied
• An error occurred while copying the file.
• An error occurred while invoking the program's main method
• An I/O error occurred while extracting nested library

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/a8a720cfcee0fa41. Report an issue: GitHub.

Appendix: source

Thrown at flink-clients/src/main/java/org/apache/flink/client/program/PackagedProgram.java:279

    }

    /** Returns all provided libraries needed to run the program. */
    public List<URL> getJobJarAndDependencies() {
        return getJobJarAndDependencies(jarFile, extractedTempLibraries, isPython);
    }

    private static List<URL> getJobJarAndDependencies(
            URL jarFile, List<File> extractedTempLibraries, boolean isPython) {
        List<URL> libs = new ArrayList<>(extractedTempLibraries.size() + 2);

        if (jarFile != null) {
            libs.add(jarFile);
        }
        for (File tmpLib : extractedTempLibraries) {
            try {
                libs.add(tmpLib.getAbsoluteFile().toURI().toURL());
            } catch (MalformedURLException e) {
                throw new RuntimeException("URL is invalid. This should not happen.", e);
            }
        }
        if (isPython) {
            libs.add(PackagedProgramUtils.getPythonJar());
        }
        return libs;
    }

    /** Returns all provided libraries needed to run the program. */
    public static List<URL> getJobJarAndDependencies(
            File jarFile, @Nullable String entryPointClassName) throws ProgramInvocationException {
        URL jarFileUrl = loadJarFile(jarFile);

        List<File> extractedTempLibraries =
                jarFileUrl == null
                        ? Collections.emptyList()
                        : extractContainedLibraries(jarFileUrl);

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