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.

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);

View on GitHub (pinned to 2f3c205e92)

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 extra
• The given program class does not have a main(String[]) metho
• Error while getting the program description
• Could not look up the main(String[]) method from the class %
• The class %s must be public.

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