英文:
java.lang.ClassCastException: java.lang.String cannot be cast to org.apache.avro.generic.GenericRecord
问题
以下是您要翻译的内容：
我正在尝试使用 KafkaConsumer 来消费记录，但我得到了以下异常。
public void kafkaConsumerRun() {
Properties prop = getProperties();
try (KafkaConsumer<String, GenericRecord> kafkaConsumer = new KafkaConsumer<>(prop)) {
kafkaConsumer.subscribe(Arrays.asList(topicName));
Schema schema = Common.SCHEMA;
log.info("SCHEMA = " + schema.toString());
Map<String, Object> eventMap = new LinkedHashMap<>();
while (true) {
ConsumerRecords<String, GenericRecord> records = kafkaConsumer.poll(Duration.ofSeconds(pollInterval));
JSONObject payloadJson = new JSONObject();
if (records.count() > 0) {
log.info(records.count() + " records in partition");
for (ConsumerRecord<String, GenericRecord> rec : records) {
GenericRecord record = SpecificData.get().deepCopy(schema, rec.value());
log.info("Priting Events before camel case conversion : " + record.toString());
for (Iterator<Schema.Field> fieldItr = record.getSchema().getFields().iterator(); fieldItr
.hasNext();) {
String fieldName = fieldItr.next().name();
Object value = record.get(fieldName);
getFieldName(fieldName, eventMap, value);
}
log.info("JSON String: " + new JSONObject(eventMap).toString());
callOrchestrator(eventMap, payloadJson);
}
}
}
} catch (Exception ex) {
log.error("Exception Caught: ", ex);
}
}
英文:
i am try to use KafkaConsumer to consume the records, but i got the below exception
public void kafkaConsumerRun() {
Properties prop = getProperties();
try (KafkaConsumer<String, GenericRecord> kafkaConsumer = new KafkaConsumer<>(prop)) {
kafkaConsumer.subscribe(Arrays.asList(topicName));
Schema schema = Common.SCHEMA;
log.info("SCHEMA = " + schema.toString());
Map<String, Object> eventMap = new LinkedHashMap<>();
while (true) {
ConsumerRecords<String, GenericRecord> records = kafkaConsumer.poll(Duration.ofSeconds(pollInterval));
JSONObject payloadJson = new JSONObject();
if (records.count() > 0) {
log.info(records.count() + " records in partition");
for (ConsumerRecord<String, GenericRecord> rec : records) {
GenericRecord record = SpecificData.get().deepCopy(schema, rec.value());
log.info("Priting Events before camel case conversion : " + record.toString());
for (Iterator<Schema.Field> fieldItr = record.getSchema().getFields().iterator(); fieldItr
.hasNext();) {
String fieldName = fieldItr.next().name();
Object value = record.get(fieldName);
getFieldName(fieldName, eventMap, value);
}
log.info("JSON String: " + new JSONObject(eventMap).toString());
callOrchestrator(eventMap, payloadJson);
}
}
}
} catch (Exception ex) {
log.error("Exception Caught: ", ex);
}
答案1
得分: 0
异常堆栈跟踪应该能够准确定位出错的那一行代码，它正告诉你发生了什么：你正在尝试将一个String实例转换为GenericRecord。确保当你将一个对象传递为Object时，在需要的时候将其强制转换回正确的类型。
英文:
The Exception stack trace should point you at exactly which line is wrong, and it is telling you exactly what is happening: there is an instance of String that you are trying to cast to GenericRecord. Make sure that when you are passing an object as an Object that you cast it back to the proper type when you need to.
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