HMCL-dev/HMCL · error · IllegalArgumentException

Invalid data URI

Error message

Invalid data URI: ${uri}

What it means

DataUri's constructor validates that the URI uses the 'data:' scheme and that its scheme-specific part is non-null and contains a ',' separating media type from payload. When the scheme-specific part is null or there is no comma, invalidUri(uri) throws IllegalArgumentException("Invalid data URI: <uri>").

Solutions

1. Include the ',' separator and payload in the data URI (e.g. 'data:text/plain,hello').
2. Verify the URI string is complete after variable/template substitution.
3. Pre-validate with URI.create(uri) and check getSchemeSpecificPart() contains ',' before constructing DataUri.

Example fix

// before
new DataUri(URI.create("data:text/plain"))
// after
new DataUri(URI.create("data:text/plain,hello"))

boolean isValidDataUri(URI uri) {
    return uri != null
        && "data".equals(uri.getScheme())
        && uri.getSchemeSpecificPart() != null
        && uri.getSchemeSpecificPart().indexOf(',') >= 0;
}
// if (!isValidDataUri(uri)) throw new IllegalArgumentException("not a data URI: " + uri);

Optional<DataUri> tryParseDataUri(URI uri) {
    try { return Optional.of(new DataUri(uri)); }
    catch (IllegalArgumentException e) { return Optional.empty(); }
}

try {
    DataUri d = new DataUri(uri);
} catch (IllegalArgumentException e) {
    LOG.warn("Rejecting invalid data URI: " + uri, e);
    // fall back to file-based resource or skip asset
}

When it happens

Trigger: Constructing new DataUri(uri) where uri.getSchemeSpecificPart() returns null (opaque URI edge cases), or where the part after 'data:' contains no ',' (e.g. 'data:text/plain' with no payload separator).

Common situations: Assets or config entries referencing 'data:' URIs that were truncated by copy/paste or template substitution; hand-written data URIs missing the comma; URIs reconstructed programmatically and losing the opaque part.

Understand the failure class

Background: "Invalid URL" errors: why new URL(), URI.parse, and reqwest::Url reject your string — missing scheme, whitespace, and bad path format — this error's family across 39 libraries.

Related errors

• bad query string
• name existing
• Texture url is empty
• Failed to download texture
• Platform is mismatch: expected

AI-assisted analysis of HMCL-dev/HMCL@24702dc5a0 (2026-09-10). Data as JSON: /api/errors/1afacfc1b4aa72e7. Report an issue: GitHub.

Appendix: source

Thrown at HMCL/src/main/java/org/jackhuang/hmcl/util/url/data/DataUri.java:54

    }

    public static boolean isDataUri(URI uri) {
        return uri != null && SCHEME.equals(uri.getScheme());
    }

    private final @NotNull String mediaType;
    private final @NotNull Charset charset;
    private final boolean base64;
    private final @NotNull String rawData;

    public DataUri(URI uri) {
        if (!uri.getScheme().equals(SCHEME)) {
            throw new IllegalArgumentException("URI scheme must be " + SCHEME);
        }

        String schemeSpecificPart = uri.getSchemeSpecificPart();
        if (schemeSpecificPart == null)
            throw invalidUri(uri);

        int comma = schemeSpecificPart.indexOf(',');
        if (comma < 0)
            throw invalidUri(uri);

        String mediaType = schemeSpecificPart.substring(0, comma);
        boolean base64 = mediaType.endsWith(";base64");
        if (base64)
            mediaType = mediaType.substring(0, mediaType.length() - ";base64".length());

        this.mediaType = mediaType.trim();
        this.charset = NetworkUtils.getCharsetFromContentType(mediaType);
        this.base64 = base64;
        this.rawData = schemeSpecificPart.substring(comma + 1);
    }

    public @NotNull String getMediaType() {
        return mediaType;

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