KafkaConnectBigQuerySinkConnector从SchemaRegistry请求不存在的键-主题名称。

可以通过以下代码解决问题：

1. 首先，确保您的Schema Registry主题在注册表中具有存在且正确配置的架构文件。

2. 然后，您需要确认Sink Connector的配置文件中设置了正确的主题名称。

3. 最后，您可以使用以下代码来验证设置是否正确：

import org.apache.kafka.connect.errors.ConnectException; 
import io.confluent.connect.avro.AvroData; 
import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient; 
import io.confluent.kafka.schemaregistry.client.rest.RestService; 
import io.confluent.kafka.serializers.KafkaAvroDeserializerConfig; 
import io.confluent.kafka.serializers.KafkaAvroSerializerConfig; 
import org.apache.kafka.common.config.ConfigDef; 
import org.apache.kafka.common.config.ConfigException; 
import org.apache.kafka.connect.connector.ConnectorContext; 
import org.apache.kafka.connect.errors.ConnectException; 
import org.apache.kafka.connect.sink.SinkConnector; 
import org.apache.kafka.connect.sink.SinkRecord; 
import org.apache.kafka.connect.sink.SinkTask; 
import org.apache.kafka.connect.sink.SinkTaskContext; 
import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 

public class BigQuerySinkTask extends SinkTask { 

private static final Logger log = LoggerFactory.getLogger(BigQuerySinkTask.class); 

private String tableName; 
private AvroData avroData; 
private SchemaRegistryClient schemaRegistry; 
private RestService restService; 

@Override 
public String version() { 
return "1.0"; 
} 

@Override 
public void start(Map<String, String> props) { 
String topicName = props.get(BigQuerySinkConnector.TOPIC_CONFIG); 
if (topicName == null || topicName.isEmpty()) { 
throw new ConnectException("Missing required configuration \"" + BigQuerySinkConnector.TOPIC_CONFIG + "\""); 
} 

tableName = props.get(BigQuerySinkConnector.TABLE_CONFIG); 
if (tableName == null || tableName.isEmpty()) { 
throw new ConnectException("Missing required configuration \"" + BigQuerySinkConnector.TABLE_CONFIG + "\""); 
} 

KafkaAvroSerializerConfig serializerConfig = new KafkaAvroSerializerConfig(props); 
KafkaAvroDeserializerConfig deserializerConfig = new KafkaAvroDeserializerConfig(props); 

HashMap<String, Object> clientConfig = new HashMap<String, Object>(); 
clientConfig.put("schema.registry.url", props.get(BigQuerySinkConnector.SCHEMA_REGISTRY_CONFIG)); 

schemaRegistry = new CachedSchemaRegistryClient(restService = new RestService(props.get(BigQuerySinkConnector.SCHEMA_REGISTRY_CONFIG)), 0); 
avroData =