如何使用KStream发送报头

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 KStreamExample {
    public static void main(String[] args) {
        // 设置Kafka Streams应用程序的配置
        Properties props = new Properties();
        props.put(StreamsConfig.APPLICATION_ID_CONFIG, "kstream-example");
        props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");

        // 创建流构建器
        StreamsBuilder builder = new StreamsBuilder();

        // 定义输入流和输出流
        KStream<String, String> inputStream = builder.stream("input-topic");
        KStream<String, String> outputStream = inputStream.mapValues(value -> "Header: " + value);

        // 发送到输出流
        outputStream.to("output-topic");

        // 构建Kafka Streams应用程序并启动
        KafkaStreams streams = new KafkaStreams(builder.build(), props);
        streams.start();
    }
}