java实现消费kafka数据 批量插入clickhouse

以下是使用Java实现消费Kafka数据并批量插入ClickHouse的示例代码：

import java.util.*;
import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.*;
import org.apache.kafka.common.serialization.*;
import ru.yandex.clickhouse.*;
import ru.yandex.clickhouse.settings.*;
import ru.yandex.clickhouse.util.*;
 
public class KafkaClickHouseConsumer {
    private static final String KAFKA_TOPIC = "test";
    private static final String KAFKA_BROKER = "localhost:9092";
    private static final String CLICKHOUSE_URL = "jdbc:clickhouse://localhost:8123/test";
    private static final String CLICKHOUSE_USER = "default";
    private static final String CLICKHOUSE_PASSWORD = "";
    private static final String CLICKHOUSE_TABLE = "test";
 
    public static void main(String[] args) {
        Properties props = new Properties();
        props.put("bootstrap.servers", KAFKA_BROKER);
        props.put("group.id", "test-consumer-group");
        props.put("enable.auto.commit", "true");
        props.put("auto.commit.interval.ms", "1000");
        props.put("session.timeout.ms", "30000");
        props.put("key.deserializer", StringDeserializer.class.getName());
        props.put("value.deserializer", StringDeserializer.class.getName());
 
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Arrays.asList(KAFKA_TOPIC));
 
        ClickHouseDataSource dataSource = new ClickHouseDataSource(CLICKHOUSE_URL, new ClickHouseProperties());
        try (ClickHouseConnection conn = dataSource.getConnection(CLICKHOUSE_USER, CLICKHOUSE_PASSWORD)) {
            conn.createStatement().execute("CREATE TABLE IF NOT EXISTS " + CLICKHOUSE_TABLE + " (id Int32, name String)");
            conn.createStatement().execute("ALTER TABLE " + CLICKHOUSE_TABLE + " DELETE WHERE 1=1");
 
            while (true) {
                ConsumerRecords<String, String> records = consumer.poll(100);
                if (records.count() == 0) {
                    continue;
                }
 
                List<ClickHouseRowBinaryStream> streams = new ArrayList<>();
                for (ConsumerRecord<String, String> record : records) {
                    int id = Integer.parseInt(record.key());
                    String name = record.value();
                    Object[] row = new Object[] { id, name };
                    ClickHouseRowBinaryStream stream = new ClickHouseRowBinaryStreamImpl(new ClickHouseColumnTypes.Object[] {
                            ClickHouseColumnTypes.Int32, ClickHouseColumnTypes.String }, new ClickHouseProperties());
                    stream.writeRow(row);
                    streams.add(stream);
                }
 
                try (ClickHousePreparedStatement statement = conn.prepareStatement("INSERT INTO " + CLICKHOUSE_TABLE + " VALUES (?, ?)")) {
                    statement.setStreams(streams);
                    statement.executeBatch();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            consumer.close();
        }
    }
}

代码的实现过程如下：

1. 配置Kafka消费者的属性，包括Kafka主题、Kafka代理、自动提交偏移量间隔等等。

2. 创建Kafka消费者并订阅主题。

3. 创建ClickHouse数据源并获取连接。

4. 创建ClickHouse表并清空所有数据。

5. 循环处理Kafka记录，将每个记录转换为ClickHouse行二进制流。

6. 使用ClickHouse预处理语句批量插入数据。

7. 处理异常并关闭Kafka消费者。

需要注意的是，此示例使用了ClickHouse JDBC驱动程序和ClickHouse JDBC行二进制流实现批量插入。您需要将以下依赖项添加到您的项目中：

<dependency>
    <groupId>ru.yandex.clickhouse</groupId>
    <artifactId>clickhouse-jdbc</artifactId>
    <version>0.2.4</version>
</dependency>
<dependency>
    <groupId>ru.yandex.clickhouse</groupId>
    <artifactId>clickhouse-jdbc-shaded</artifactId>
    <version>0.2.4</version>
</dependency>

此外，您需要根据实际情况修改示例代码中的常量，例如Kafka主题、Kafka代理、ClickHouse URL、ClickHouse用户和密码以及ClickHouse表名。