opendataloader-project/opendataloader-pdf · error · IOException

pdf2img inner RESULT is null

Error message

pdf2img inner RESULT is null

What it means

RESULT[0] exists but its inner RESULT field (expected to hold PAGE_PNG_DATA) is null. This means the pdf2img envelope shape is unexpected — the backend returned a RESULT array whose first element lacks the nested RESULT object. Per-page IOException, caught and logged by table/figure handlers.

Source

Thrown at java/opendataloader-pdf-core/src/main/java/org/opendataloader/pdf/hybrid/HancomAIClient.java:706

                throw new IOException("pdf2img returned HTTP " + response.code());
            }

            ResponseBody respBody = response.body();
            if (respBody == null) {
                throw new IOException("pdf2img returned empty body");
            }

            JsonNode root = objectMapper.readTree(respBody.string());
            // Navigate: RESULT[0].RESULT.PAGE_PNG_DATA
            JsonNode resultArr = root.get("RESULT");
            if (resultArr == null || !resultArr.isArray() || resultArr.size() == 0) {
                throw new IOException("pdf2img RESULT is empty");
            }

            JsonNode pageResult = resultArr.get(0);
            JsonNode innerResult = pageResult.get("RESULT");
            if (innerResult == null) {
                throw new IOException("pdf2img inner RESULT is null");
            }

            String pngBase64 = innerResult.has("PAGE_PNG_DATA")
                ? innerResult.get("PAGE_PNG_DATA").asText() : null;
            if (pngBase64 == null || pngBase64.isEmpty()) {
                throw new IOException("pdf2img PAGE_PNG_DATA is empty");
            }

            byte[] pngBytes;
            try {
                pngBytes = Base64.getDecoder().decode(pngBase64);
            } catch (IllegalArgumentException e) {
                // fetchPageImage is declared to throw IOException and callers catch
                // only IOException. Escaping IAE would abort the whole conversion
                // instead of skipping the failed page.
                throw new IOException("pdf2img PAGE_PNG_DATA is not valid Base64", e);
            }
            BufferedImage image = ImageIO.read(new ByteArrayInputStream(pngBytes));

View on GitHub (pinned to a7789b8e77)

Solutions

1. Inspect the raw RESULT[0] payload to see why the nested RESULT is absent
2. Check backend pdf2img version matches the expected envelope
3. Retry the page; if persistent, accept the per-page skip
4. Review backend logs for the PAGE_INDEX that produced the malformed entry

try {
    return cache.getOrFetch(pageNum, idx -> client.fetchPageImage(pdf, idx, crop));
} catch (IOException e) {
    if (e.getMessage().contains("inner RESULT is null")) {
        log.warn("page {} pdf2img envelope malformed (no nested RESULT)", pageNum);
    }
    continue;
}

When it happens

Trigger: resultArr.get(0) is present but pageResult.get("RESULT") returns null inside fetchPageImage.

Common situations: Backend pdf2img returned an error/wrapper object in RESULT[0] without the nested RESULT (e.g. an error envelope); version skew altering the nesting; backend returning metadata-only entries.

Related errors

• pdf2img returned empty body
• pdf2img RESULT is empty
• pdf2img PAGE_PNG_DATA is empty
• pdf2img PAGE_PNG_DATA is not valid Base64
• Invalid response: missing 'document' field

AI-assisted analysis of opendataloader-project/opendataloader-pdf@a7789b8e77 (2026-08-14). Data as JSON: /api/errors/7136851fcae18bd7. Report an issue: GitHub.