import org.apache.kafka.streams.KafkaStreams;
import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.StreamsConfig;
import org.apache.kafka.streams.kstream.KStream;
import java.util.Properties;
public class KafkaStreamsExample {
public static void main(String[] args) {
// define and configure properties for Kafka Stream
Properties properties = new Properties();
properties.put(StreamsConfig.APPLICATION_ID_CONFIG, "my-streams-app");
properties.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
// create an instance of StreamsBuilder to define topology
StreamsBuilder builder = new StreamsBuilder();
// define input and output streams
KStream inputStream = builder.stream("my-input-topic");
KStream outputStream1 = inputStream.filter((key, value) -> value.contains("filter-condition"));
KStream outputStream2 = inputStream.mapValues(value -> value.toUpperCase());
// start Kafka Stream with defined topology and properties
KafkaStreams streams = new KafkaStreams(builder.build(), properties);
streams.start();
// add shutdown hook to cleanly close Kafka Stream on shut down
Runtime.getRuntime().addShutdownHook(new Thread(streams::close));
}
}
以上代码示例演示了如何定义一个Kafka Stream应用程序,并创建具有两个函数的输入和输出数据流。根据示例中提供的信息,可以进一步确定应用程序中的问题并进行调试和修复。