如何使用node.js为上传到谷歌云存储的文件设置内容类型

npm install --save @google-cloud/storage

const { Storage } = require('@google-cloud/storage');
const storage = new Storage();

async function uploadFileWithContentType(bucketName, sourceFilePath, destinationFileName, contentType) {
  const bucket = storage.bucket(bucketName);

  // 创建一个可写流
  const file = bucket.file(destinationFileName);
  const writeStream = file.createWriteStream({
    metadata: {
      contentType: contentType,
    },
  });

  // 将文件内容写入到谷歌云存储
  const fs = require('fs');
  const readStream = fs.createReadStream(sourceFilePath);
  readStream.pipe(writeStream);

  return new Promise((resolve, reject) => {
    writeStream.on('error', (err) => {
      reject(err);
    });

    writeStream.on('finish', () => {
      resolve(`File ${destinationFileName} uploaded to ${bucketName}.`);
    });
  });
}

// 使用示例
(async () => {
  const bucketName = 'your-bucket-name';
  const sourceFilePath = './path/to/your/local/file';
  const destinationFileName = 'example.txt';
  const contentType = 'text/plain';

  try {
    const result = await uploadFileWithContentType(bucketName, sourceFilePath, destinationFileName, contentType);
    console.log(result);
  } catch (error) {
    console.error('Error uploading file:', error);
  }
})();