apache/seatunnel · error · RuntimeException

Json deserialization exception.

Error message

Json deserialization exception.

What it means

JsonUtils.parseArray catches IOException from Jackson readTree — thrown when the text is not valid JSON or cannot be read — and rethrows it as this RuntimeException, so it marks the input as unparsable JSON for array parsing.

Source

Thrown at seatunnel-common/src/main/java/org/apache/seatunnel/common/utils/JsonUtils.java:286

        return parseObject(text.getBytes(StandardCharsets.UTF_8));
    }

    public static ObjectNode parseObject(byte[] content) {
        try {
            return (ObjectNode) OBJECT_MAPPER.readTree(content);
        } catch (IOException e) {
            throw new RuntimeException(
                    "String json deserialization exception."
                            + new String(content, StandardCharsets.UTF_8),
                    e);
        }
    }

    public static ArrayNode parseArray(String text) {
        try {
            return (ArrayNode) OBJECT_MAPPER.readTree(text);
        } catch (Exception e) {
            throw new RuntimeException("Json deserialization exception.", e);
        }
    }

    /** json serializer */
    public static class JsonDataSerializer extends JsonSerializer<String> {

        @Override
        public void serialize(String value, JsonGenerator gen, SerializerProvider provider)
                throws IOException {
            gen.writeRawValue(value);
        }
    }

    /** json data deserializer */
    public static class JsonDataDeserializer extends JsonDeserializer<String> {

        @Override
        public String deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {

View on GitHub (pinned to cf67b549a7)

Solutions

1. Inspect the chained cause and the input string; confirm the text starts with '['
2. Handle empty input explicitly before calling parseArray
3. If the source may return an object wrapper, read it as ObjectNode and extract the array field instead
4. Fix JSON syntax issues (trailing commas, single quotes, comments) in the producer

Example fix

// before
ArrayNode arr = JsonUtils.parseArray(""); // blank input throws
// after
ArrayNode arr = text == null || text.isBlank() ? null : JsonUtils.parseArray(text);

ArrayNode safeParseArray(String text) {
    if (text == null || text.isBlank()) return null;
    try {
        JsonNode n = JsonUtils.parseObject(text.getBytes(StandardCharsets.UTF_8));
        return n != null && n.isArray() ? (ArrayNode) n : null;
    } catch (RuntimeException e) { return null; }
}

boolean isArrayPayload(String text) { return text != null && text.trim().startsWith("["); }

try {
    ArrayNode arr = JsonUtils.parseArray(text);
} catch (RuntimeException e) {
    log.error("invalid array json: {}", e.getCause());
    arr = JsonUtils.getNodeFactory().arrayNode();
}

When it happens

Trigger: Calling JsonUtils.parseArray(text) with malformed JSON, an empty/blank string, or a JSON object/scalar which readTree cannot produce an ArrayNode from (leading to ClassCastException or parse error).

Common situations: Consuming third-party list endpoints that sometimes return a single object, reading JSON arrays from files with trailing commas or comments, blank responses from failed requests.

Understand the failure class

Background: JSON parse error: "Unexpected token" / "not valid JSON" / "failed to parse" — what JSON parsers are really complaining about — this error's family across 45 libraries.

Related errors

• Json parse object exception!
• Json parse list exception!
• json to map exception!
• Json parse object exception.
• String json deserialization exception.<content>

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/b7c2970bbdae5571. Report an issue: GitHub.