junit-team/junit5 · error · PreconditionViolationException

Failed to create a java.net.URI from: ${uri}

Error message

Failed to create a java.net.URI from: ${uri}

What it means

Thrown by DiscoverySelectors.selectUri(String) (line 80-88) when 'new URI(uri)' raises URISyntaxException. It is wrapped in a PreconditionViolationException. The blank-string guard runs first (Preconditions.notBlank), so this specifically means the string is non-blank but syntactically invalid per java.net.URI's strict RFC parsing.

Source

Thrown at junit-platform-engine/src/main/java/org/junit/platform/engine/discovery/DiscoverySelectors.java:86

	/**
	 * Create a {@code UriSelector} for the supplied URI.
	 *
	 * @param uri the URI to select; never {@code null} or blank
	 * @see UriSelector
	 * @see #selectUri(URI)
	 * @see #selectFile(String)
	 * @see #selectFile(File)
	 * @see #selectDirectory(String)
	 * @see #selectDirectory(File)
	 */
	public static UriSelector selectUri(String uri) {
		Preconditions.notBlank(uri, "URI must not be null or blank");
		try {
			return new UriSelector(new URI(uri));
		}
		catch (URISyntaxException ex) {
			throw new PreconditionViolationException("Failed to create a java.net.URI from: " + uri, ex);
		}
	}

	/**
	 * Create a {@code UriSelector} for the supplied {@link URI}.
	 *
	 * @param uri the URI to select; never {@code null}
	 * @see UriSelector
	 * @see #selectUri(String)
	 * @see #selectFile(String)
	 * @see #selectFile(File)
	 * @see #selectDirectory(String)
	 * @see #selectDirectory(File)
	 */
	public static UriSelector selectUri(URI uri) {
		Preconditions.notNull(uri, "URI must not be null");
		return new UriSelector(uri);
	}

View on GitHub (pinned to 956246301e)

Solutions

1. Pre-construct a URI with java.net.URI or Path.toUri() and pass it to selectUri(URI) to avoid re-parsing.
2. Percent-encode the string (URLEncoder / URI multi-arg constructor) before passing to selectUri(String).
3. For local files use DiscoverySelectors.selectFile(path) instead of a hand-built file:// URI.
4. Validate first: new URI(s) in a try/catch and log the exact URISyntaxException index/message.

Example fix

// before
var selector = DiscoverySelectors.selectUri("C:\\Users\\me\\tests\\data.xml"); // backslashes -> throws

// after
URI uri = Path.of("C:\\Users\\me\\tests\\data.xml").toUri();
var selector = DiscoverySelectors.selectUri(uri);

URI uri;
try { uri = new URI(rawString); }
catch (URISyntaxException e) { throw new IllegalArgumentException("bad URI: " + rawString, e); }
var selector = DiscoverySelectors.selectUri(uri); // URI overload avoids re-parse

static boolean isParsableUri(String s) {
    try { new URI(s); return true; } catch (URISyntaxException e) { return false; }
}

try {
    return DiscoverySelectors.selectUri(rawString);
} catch (PreconditionViolationException e) {
    throw new IllegalArgumentException("Not a valid URI: " + rawString, e.getCause());
}

When it happens

Trigger: Calling DiscoverySelectors.selectUri(s) with an unencoded URI containing illegal characters (spaces, stray brackets, backslashes, or a missing scheme). Note: passing a java.net.URI object to selectUri(URI) bypasses this entirely.

Common situations: Passing a Windows file path (C:\Users\...) instead of a file:// URI; copy-pasting a URL with spaces or query characters not percent-encoded; mixing file: and raw paths; using a relative path where an absolute URI is expected.

Related errors

• '%s' is not a well-formed UniqueId segment
• Failed to transform configuration parameter with key '%s' an
• Could not find any resource(s) with name: ${this.classpathRe
• Failed to retrieve canonical path for file: ${file}
• Failed to retrieve canonical path for directory: ${directory

AI-assisted analysis of junit-team/junit5@956246301e (2026-08-04). Data as JSON: /data/errors/385dbbe6e004900d.json. Report an issue: GitHub.