Java jar可执行文件无法读取dropbox上的excel文件

<dependency>
    <groupId>com.dropbox.core</groupId>
    <artifactId>dropbox-core-sdk</artifactId>
    <version>3.0.11</version>
</dependency>

import com.dropbox.core.DbxRequestConfig;
import com.dropbox.core.v2.DbxClientV2;
import com.dropbox.core.v2.files.FileMetadata;
import com.dropbox.core.v2.files.ListFolderResult;
import com.dropbox.core.v2.files.Metadata;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class DropboxExample {
    private static final String ACCESS_TOKEN = "YOUR_ACCESS_TOKEN";

    public static void main(String[] args) {
        // 创建Dropbox客户端
        DbxRequestConfig config = DbxRequestConfig.newBuilder("dropbox/java-tutorial").build();
        DbxClientV2 client = new DbxClientV2(config, ACCESS_TOKEN);

        try {
            // 列出dropbox根目录下的文件和文件夹
            ListFolderResult result = client.files().listFolder("");
            while (true) {
                for (Metadata metadata : result.getEntries()) {
                    System.out.println(metadata.getPathLower());
                    if (metadata.getName().endsWith(".xlsx")) {
                        // 下载excel文件
                        try (OutputStream outputStream = new FileOutputStream(metadata.getName())) {
                            FileMetadata fileMetadata = client.files().download(metadata.getPathLower())
                                    .download(outputStream);
                            System.out.println("下载完成：" + fileMetadata.getPathLower());
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }

                if (!result.getHasMore()) {
                    break;
                }

                result = client.files().listFolderContinue(result.getCursor());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}