可以使用seek()方法來指定offset進行讀取。

示例代碼如下：

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.TopicPartition;

import java.util.Arrays;
import java.util.Properties;

public class KafkaOffsetReader {

    public static void main(String[] args) {
        String topicName = "my_topic";
        int partition = 0;
        long offset = 100;

        // 設置Kafka consumer的配置
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "my_consumer_group");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);

        // 創建TopicPartition對象來指定要讀取的partition和offset
        TopicPartition topicPartition = new TopicPartition(topicName, partition);

        // 使用seek()方法來指定offset
        consumer.assign(Arrays.asList(topicPartition));
        consumer.seek(topicPartition, offset);

        // 開始消費消息
        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for (ConsumerRecord<String, String> record : records) {
                System.out.println("Received message: " + record.value());
            }
        }
    }
}

在上述示例中，我們創建了一個Kafka consumer，并使用seek()方法將consumer的offset設置為指定的值。然后，我們使用poll()方法來獲取消息，從指定的offset開始消費。