apache/dolphinscheduler · error · IllegalArgumentException

At least one path should be provided

Error message

At least one path should be provided

What it means

FileUtils.concatFilePath joins path segments into a single filesystem path using the platform separator. It throws IllegalArgumentException("At least one path should be provided") when invoked with a zero-length varargs array, since there is nothing to concatenate.

Source

Thrown at dolphinscheduler-common/src/main/java/org/apache/dolphinscheduler/common/utils/FileUtils.java:294

            Files.createDirectories(path);
        } else {
            Path parent = path.getParent();
            if (parent != null && !parent.toFile().exists()) {
                createDirectoryWithPermission(parent, permissions);
            }

            try {
                Files.createDirectory(path);
                Files.setPosixFilePermissions(path, permissions);
            } catch (FileAlreadyExistsException fileAlreadyExistsException) {
                log.error("The directory: {} already exists", path);
            }
        }
    }

    public static String concatFilePath(String... paths) {
        if (paths.length == 0) {
            throw new IllegalArgumentException("At least one path should be provided");
        }
        StringBuilder finalPath = new StringBuilder(paths[0]);
        if (StringUtils.isEmpty(finalPath)) {
            throw new IllegalArgumentException("The path should not be empty");
        }
        String separator = File.separator;
        for (int i = 1; i < paths.length; i++) {
            String path = paths[i];
            if (StringUtils.isEmpty(path)) {
                throw new IllegalArgumentException("The path should not be empty");
            }
            if (finalPath.toString().endsWith(separator) && path.startsWith(separator)) {
                finalPath.append(path.substring(separator.length()));
                continue;
            }
            if (!finalPath.toString().endsWith(separator) && !path.startsWith(separator)) {
                finalPath.append(separator).append(path);
                continue;

View on GitHub (pinned to 02eac45a1b)

Solutions

1. Guard the caller: if paths.length == 0, supply a default base path or skip the operation
2. Validate the source list is non-empty before spreading it into the varargs call
3. If an empty path list is legitimate, return a sensible default (e.g. the working directory) instead of calling concatFilePath
4. Check the upstream config/env value feeding the list — an unset key usually renders as an empty array

Example fix

// before
String full = FileUtils.concatFilePath(parts.toArray(new String[0])); // IAE when parts is empty

// after
if (parts.isEmpty()) {
    throw new IllegalArgumentException("No path segments configured");
}
String full = FileUtils.concatFilePath(parts.toArray(new String[0]));

if (paths == null || paths.length == 0) {
    throw new IllegalArgumentException("concatFilePath requires at least one path segment");
}

try {
    String path = FileUtils.concatFilePath(segments);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("At least one path")) {
        log.error("No path segments provided; check the configured path list");
    } else throw e;
}

When it happens

Trigger: Calling FileUtils.concatFilePath() with no arguments — typically by spreading an empty array/list (concatFilePath(paths.toArray(new String[0])) where paths is empty) rather than a literal empty call.

Common situations: Building a resource path from a config list or split() result that turned out empty; passing an environment-derived path list where the env var is unset; filter/map chains that removed all candidate paths before concatenation.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

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• data: %s should be a validate data string - yyyy-MM-dd HH:mm
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AI-assisted analysis of apache/dolphinscheduler@02eac45a1b (2026-09-06). Data as JSON: /api/errors/fb6718535cc1cfde. Report an issue: GitHub.