in src/main/java/org/apache/doris/kafka/connector/converter/RecordService.java [306:318]
public String getProcessedRecord(SinkRecord record) {
String processedRecord;
if (record.value() instanceof Struct) {
processedRecord = processStructRecord(record);
} else if (record.value() instanceof List) {
processedRecord = processListRecord(record);
} else if (record.value() instanceof Map) {
processedRecord = processMapRecord(record);
} else {
processedRecord = record.value().toString();
}
return processedRecord;
}