写一个用java实现的kafka高并发多线程数据入库示例，要求一次读取所有别人发送的数据，处理后多线程批量入库

以下是一个基于Java实现的Kafka高并发多线程数据入库示例：

import java.util.Arrays;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;

public class KafkaConsumerExample {

    private final static String TOPIC_NAME = "my-topic";
    private final static String BOOTSTRAP_SERVERS = "localhost:9092";
    private final static String GROUP_ID = "my-group";

    private final static int NUM_THREADS = 4;

    private static ExecutorService executor = Executors.newFixedThreadPool(NUM_THREADS);

    public static void main(String[] args) throws Exception {
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, GROUP_ID);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Arrays.asList(TOPIC_NAME));

        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for (ConsumerRecord<String, String> record : records) {
                executor.submit(new DatabaseWriter(record));
            }
        }
    }

    private static class DatabaseWriter implements Runnable {
        private final ConsumerRecord<String, String> record;

        public DatabaseWriter(ConsumerRecord<String, String> record) {
            this.record = record;
        }

        @Override
        public void run() {
            // TODO: 进行数据处理和批量入库操作
        }
    }
}

上述代码创建了一个Kafka消费者，订阅名为`my-topic`的主题，并且在消费时将每条消息交给线程池中的一个线程来处理。在每个线程中，可以进行数据处理和批量入库操作，以实现高并发、多线程的数据入库。