如何在Java中以编程方式检查Pulsar主题的存在？

import org.apache.pulsar.client.admin.PulsarAdmin;
import org.apache.pulsar.client.admin.PulsarAdminException;
import org.apache.pulsar.client.admin.PulsarAdminBuilder;
import org.apache.pulsar.client.admin.PulsarAdminException.NotFoundException;

public class PulsarTopicChecker {

    public static void main(String[] args) {
        String serviceUrl = "pulsar://localhost:6650"; // Pulsar服务的URL
        String topicName = "my-topic"; // 要检查的主题名称

        PulsarAdmin pulsarAdmin = null;
        try {
            PulsarAdminBuilder adminBuilder = PulsarAdmin.builder().serviceHttpUrl(serviceUrl);
            pulsarAdmin = adminBuilder.build();
            // 使用PulsarAdmin对象检查主题是否存在
            pulsarAdmin.topics().getStats(topicName);
            System.out.println("主题存在");
        } catch (NotFoundException e) {
            System.out.println("主题不存在");
        } catch (PulsarAdminException e) {
            System.out.println("检查主题存在时出现异常: " + e.getMessage());
        } finally {
            if (pulsarAdmin != null) {
                pulsarAdmin.close();
            }
        }
    }
}