iflytek/astron-agent · warning · IllegalArgumentException

Base64 string cannot be empty

Error message

Base64 string cannot be empty

What it means

base64ToImageInputStream converts a Base64-encoded image string into an InputStream. It validates the input up-front and throws IllegalArgumentException when the string is null or blank, because decoding an empty value can never produce a valid image stream.

Solutions

1. Check the Base64 string for null/blank before calling and return a client-friendly validation error
2. Fix the upstream producer so the image field is always populated when this API is invoked
3. If a data URL is expected, strip the "data:image/...;base64," prefix and verify the remainder is non-empty

Example fix

// before
InputStream in = ImageUtil.base64ToImageInputStream(request.getImageBase64());
// after
String b64 = request.getImageBase64();
if (b64 == null || b64.trim().isEmpty()) {
    throw new BadRequestException("imageBase64 is required");
}
InputStream in = ImageUtil.base64ToImageInputStream(b64);

if (b64 == null || b64.trim().isEmpty()) { throw new BadRequestException("imageBase64 is required"); }

boolean isValidBase64(String s) { return s != null && !s.trim().isEmpty(); }

When it happens

Trigger: Calling ImageUtil.base64ToImageInputStream(null), an empty string "", or a whitespace-only string like " ".

Common situations: An upload request missing the image field, a frontend sending an empty data attribute, or a data-URL prefix stripped incorrectly leaving an empty payload.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• 99999
• Input stream cannot be empty
• Compression ratio must be between 0-1
• User UID cannot be null
• DUPLICATE_BOT_NAME

AI-assisted analysis of iflytek/astron-agent@5e758547a8 (2026-09-12). Data as JSON: /api/errors/691329e2c2313552. Report an issue: GitHub.

Appendix: source

Thrown at console/backend/hub/src/main/java/com/iflytek/astron/console/hub/util/ImageUtil.java:30

import static com.iflytek.astron.console.commons.constant.ResponseEnum.SYSTEM_ERROR;

/**
 * Image processing utility class
 *
 */
@Slf4j
public class ImageUtil {

    /**
     * Convert base64 string to InputStream
     *
     * @param base64String Base64 encoded image string
     * @return InputStream object
     */
    public static InputStream base64ToImageInputStream(String base64String) {
        if (base64String == null || base64String.trim().isEmpty()) {
            throw new IllegalArgumentException("Base64 string cannot be empty");
        }

        try {
            byte[] byteArray = Base64.getDecoder().decode(base64String);
            return new ByteArrayInputStream(byteArray);
        } catch (Exception e) {
            log.error("Failed to convert Base64 string to InputStream", e);
            throw new BusinessException(SYSTEM_ERROR);
        }
    }

    /**
     * Compress image
     *
     * @param inputStream Original image input stream
     * @param scale Compression ratio (0.0-1.0)
     * @return Compressed image input stream
     */

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