无法从我的Google App Engine Servlet (Java)在我的Google云存储中存储对象

import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 创建Google云存储客户端
        Storage storage = StorageOptions.getDefaultInstance().getService();

        // 创建存储桶
        String bucketName = "my-bucket";
        storage.create(BlobInfo.newBuilder(bucketName, "my-object").build());

        // 设置对象的元数据
        BlobInfo blobInfo = BlobInfo.newBuilder(bucketName, "my-object")
                .setContentType("text/plain")
                .build();

        // 写入对象内容
        byte[] content = "Hello, Cloud Storage!".getBytes();
        storage.writer(blobInfo).write(content);

        resp.getWriter().println("Object stored in Google Cloud Storage.");
    }
}