使用KafkaStream处理器应用编程接口时将输出打印到控制台

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 KafkaStreamExample {
    public static void main(String[] args) {
        // 设置KafkaStream配置
        Properties props = new Properties();
        props.put(StreamsConfig.APPLICATION_ID_CONFIG, "kafka-stream-example");
        props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");

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

        // 创建输入流
        KStream<String, String> inputStream = builder.stream("input-topic");

        // 处理数据并将结果打印到控制台
        inputStream.foreach((key, value) -> System.out.println("Key: " + key + ", Value: " + value));

        // 构建KafkaStream处理器
        KafkaStreams streams = new KafkaStreams(builder.build(), props);

        // 启动处理器
        streams.start();

        // 添加关闭钩子，确保在应用程序关闭时优雅地关闭处理器
        Runtime.getRuntime().addShutdownHook(new Thread(streams::close));
    }
}