apereo/cas · warning

File [ ] is does not exist, is not readable or is empty

Error message

File [{}] is does not exist, is not readable or is empty

What it means

GenerateYamlRegisteredServiceCommand logs this warning when the JSON service definition file passed to generateYaml does not exist, is unreadable, or is empty, so there is nothing to convert to YAML. The command catches any conversion error, logs it, and finishes without producing the YAML output.

Solutions

1. Pass the correct absolute path to an existing JSON registered service file
2. Verify the file is non-empty and readable (cat / ls -l the path)
3. Check the current working directory when using relative paths
4. Re-create or re-copy the JSON service definition if it is truncated

Example fix

// before
cas generate-yaml-registered-service --file svc.json
// after
cas generate-yaml-registered-service --file /etc/cas/services/Example-1000.json

File f = new File(path);
if (!f.isFile() || !f.canRead() || f.length() == 0)
    throw new IllegalArgumentException("Service JSON file missing/empty/unreadable: " + path);

When it happens

Trigger: Running 'cas generate-yaml-registered-service' with --file pointing at a path that does not exist, has no read permission, or is a zero-byte file.

Common situations: Typo in the JSON service file path; relative path resolved from a different working directory; truncated/empty file from a failed copy or download; file created but serializer never wrote content.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• File [ ] is does not exist, is not readable or is empty
• Configuration file [ ] is not readable/writable or is not a…
• The service definition file could not be saved at
• subordinate directory
• subordinate directory

AI-assisted analysis of apereo/cas@e7288fc434 (2026-09-08). Data as JSON: /api/errors/478fe3b601355c83. Report an issue: GitHub.

Appendix: source

Thrown at support/cas-server-support-shell-core/src/main/java/org/apereo/cas/shell/commands/services/GenerateYamlRegisteredServiceCommand.java:74

        try {
            val validator = new RegisteredServiceJsonSerializer(applicationContext);
            val basicFileAttributes = Files.readAttributes(filePath.toPath(), BasicFileAttributes.class);
            if (basicFileAttributes.isRegularFile() && filePath.exists()
                && filePath.canRead() && basicFileAttributes.size() > 0) {
                val svc = validator.from(filePath);
                LOGGER.info("Service [{}] is valid at [{}].", svc.getName(), filePath.getCanonicalPath());
                val yaml = new RegisteredServiceYamlSerializer(applicationContext);
                try (val writer = new StringWriter()) {
                    yaml.to(writer, svc);
                    LOGGER.info(writer.toString());

                    if (result != null) {
                        yaml.to(result, svc);
                        LOGGER.info("YAML service definition is saved at [{}].", result.getCanonicalPath());
                    }
                }
            } else {
                LOGGER.warn("File [{}] is does not exist, is not readable or is empty", filePath.getCanonicalPath());
            }
        } catch (final Exception e) {
            LOGGER.error("Could not understand and validate [{}]: [{}]", filePath.getPath(), e.getMessage());
        } finally {
            LOGGER.info("-".repeat(SEP_LINE_LENGTH));
        }

    }
}

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