如何使用java服务帐号验证GCP PubSub主题是否有写权限？

import com.google.api.gax.rpc.ApiException;
import com.google.cloud.pubsub.v1.TopicAdminClient;
import com.google.iam.v1.TestIamPermissionsRequest;
import com.google.iam.v1.TestIamPermissionsResponse;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class PubSubPermissionsVerifier {

    public static void main(String[] args) {
        // 项目ID
        String projectId = "your-project-id";
        // 主题ID
        String topicId = "your-topic-id";
        // 服务帐号密钥文件路径
        String keyFilePath = "path/to/keyfile.json";

        try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {
            // 加载服务帐号密钥文件
            GoogleCredentials credentials = GoogleCredentials.fromStream(new FileInputStream(keyFilePath));
            // 设置身份验证
            topicAdminClient.setCredentialsProvider(FixedCredentialsProvider.create(credentials));

            // 验证主题写权限
            List<String> permissions = Arrays.asList("pubsub.topics.publish");
            TestIamPermissionsRequest request =
                    TestIamPermissionsRequest.newBuilder()
                            .setResource("projects/" + projectId + "/topics/" + topicId)
                            .addAllPermissions(permissions)
                            .build();
            TestIamPermissionsResponse response = topicAdminClient.testIamPermissions(request);

            // 处理验证结果
            List<String> testedPermissions = response.getPermissionsList();
            if (testedPermissions.containsAll(permissions)) {
                System.out.println("具有写权限");
            } else {
                System.out.println("没有写权限");
            }
        } catch (IOException | ApiException e) {
            e.printStackTrace();
        }
    }
}