向 Cloud Storage 上传文件 (Web)

Cloud Storage for Firebase 可让您快速轻松地将文件上传到 Firebase 提供和管理的 Cloud Storage 存储桶中。

注意：默认情况下，需要经过 Firebase Authentication 身份验证才能对 Cloud Storage for Firebase 存储桶中的数据或文件执行操作。您可以更改 Cloud Storage 的 Firebase Security Rules，以允许在特定情况下进行未经身份验证的访问。不过，在大多数情况下，我们强烈建议限制访问权限并设置稳健的安全规则（尤其是对于生产应用）。请注意，如果您使用 Google App Engine 且默认 Cloud Storage 存储桶的名称格式为 *.appspot.com，则可能需要考虑您的安全规则对 App Engine 文件的访问权限有何影响。

注意：对于 Spark 方案项目，Firebase 会阻止 Cloud Storage for Firebase 和 Firebase Hosting 上传和托管某些可执行文件类型：.exe、.dll 和 .bat 扩展名 (Windows)、.apk 扩展名 (Android) 和 .ipa 扩展名 (Apple)。此政策旨在防止我们的平台上出现滥用行为。Blaze 方案中的项目不受影响。如需了解详情，请参阅此常见问题解答。

上传文件

如需将文件上传到 Cloud Storage，首先要创建对文件的完整路径（包括文件名）的引用。

Web

import { getStorage, ref } from "firebase/storage";

// Create a root reference
const storage = getStorage();

// Create a reference to 'mountains.jpg'
const mountainsRef = ref(storage, 'mountains.jpg');

// Create a reference to 'images/mountains.jpg'
const mountainImagesRef = ref(storage, 'images/mountains.jpg');

// While the file names are the same, the references point to different files
mountainsRef.name === mountainImagesRef.name;           // true
mountainsRef.fullPath === mountainImagesRef.fullPath;   // false 
storage_upload_ref.js

Web

// Create a root reference
var storageRef = firebase.storage().ref();

// Create a reference to 'mountains.jpg'
var mountainsRef = storageRef.child('mountains.jpg');

// Create a reference to 'images/mountains.jpg'
var mountainImagesRef = storageRef.child('images/mountains.jpg');

// While the file names are the same, the references point to different files
mountainsRef.name === mountainImagesRef.name;           // true
mountainsRef.fullPath === mountainImagesRef.fullPath;   // false 
upload-files.js

通过 Blob 或 File 上传

创建合适的引用后，调用 uploadBytes() 方法。uploadBytes() 通过 JavaScript File 和 Blob API 接受文件，并将它们上传至 Cloud Storage。

Web

import { getStorage, ref, uploadBytes } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'some-child');

// 'file' comes from the Blob or File API
uploadBytes(storageRef, file).then((snapshot) => {
  console.log('Uploaded a blob or file!');
});
storage_upload_blob.js

Web

// 'file' comes from the Blob or File API
ref.put(file).then((snapshot) => {
  console.log('Uploaded a blob or file!');
});
upload-files.js

通过字节数组上传

除了 File 和 Blob 类型外，uploadBytes() 也可以将 Uint8Array 上传至 Cloud Storage。

Web

import { getStorage, ref, uploadBytes } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'some-child');

const bytes = new Uint8Array([0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21]);
uploadBytes(storageRef, bytes).then((snapshot) => {
  console.log('Uploaded an array!');
});
storage_upload_bytes.js

Web

var bytes = new Uint8Array([0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21]);
ref.put(bytes).then((snapshot) => {
  console.log('Uploaded an array!');
});
upload-files.js

通过字符串上传

如果无法使用 Blob、File 或 Uint8Array，您可以使用 uploadString() 方法将一个原始 base64、base64url 或 data_url 编码的字符串上传至 Cloud Storage。

Web

import { getStorage, ref, uploadString } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'some-child');

// Raw string is the default if no format is provided
const message = 'This is my message.';
uploadString(storageRef, message).then((snapshot) => {
  console.log('Uploaded a raw string!');
});

// Base64 formatted string
const message2 = '5b6p5Y+344GX44G+44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
uploadString(storageRef, message2, 'base64').then((snapshot) => {
  console.log('Uploaded a base64 string!');
});

// Base64url formatted string
const message3 = '5b6p5Y-344GX44G-44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
uploadString(storageRef, message3, 'base64url').then((snapshot) => {
  console.log('Uploaded a base64url string!');
});

// Data URL string
const message4 = 'data:text/plain;base64,5b6p5Y+344GX44G+44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
uploadString(storageRef, message4, 'data_url').then((snapshot) => {
  console.log('Uploaded a data_url string!');
});
storage_upload_string.js

Web

// Raw string is the default if no format is provided
var message = 'This is my message.';
ref.putString(message).then((snapshot) => {
  console.log('Uploaded a raw string!');
});

// Base64 formatted string
var message = '5b6p5Y+344GX44G+44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
ref.putString(message, 'base64').then((snapshot) => {
  console.log('Uploaded a base64 string!');
});

// Base64url formatted string
var message = '5b6p5Y-344GX44G-44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
ref.putString(message, 'base64url').then((snapshot) => {
  console.log('Uploaded a base64url string!');
});

// Data URL string
var message = 'data:text/plain;base64,5b6p5Y+344GX44G+44GX44Gf77yB44GK44KB44Gn44Go44GG77yB';
ref.putString(message, 'data_url').then((snapshot) => {
  console.log('Uploaded a data_url string!');
});
upload-files.js

由于引用定义了文件的完整路径，因此请确保您是将文件上传至非空路径。

添加文件元数据

上传文件时，您还可以指定该文件的元数据。 这些元数据包含典型的文件元数据属性，如 name、size 和 contentType（通常称为 MIME 类型）。如果文件存储在磁盘上，Cloud Storage 会利用文件的扩展名自动推断内容类型，但如果您在元数据中指定了 contentType，指定的内容类型会覆盖自动检测到的类型。如果未指定 contentType 元数据，且文件没有文件扩展名，则 Cloud Storage 默认类型为 application/octet-stream。如需详细了解文件元数据，请参阅使用文件元数据部分。

Web

import { getStorage, ref, uploadBytes } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'images/mountains.jpg');

// Create file metadata including the content type
/** @type {any} */
const metadata = {
  contentType: 'image/jpeg',
};

// Upload the file and metadata
const uploadTask = uploadBytes(storageRef, file, metadata);
storage_upload_metadata.js

Web

// Create file metadata including the content type
var metadata = {
  contentType: 'image/jpeg',
};

// Upload the file and metadata
var uploadTask = storageRef.child('images/mountains.jpg').put(file, metadata);
upload-files.js

管理上传

除了启动上传外，您还可以分别使用 pause()、resume() 和 cancel() 方法来暂停、继续和取消上传。调用 pause() 或 resume() 会引发 pause 或 running 状态更改。调用 cancel() 方法会导致上传失败，并返回表示上传已取消的错误。

Web

import { getStorage, ref, uploadBytesResumable } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'images/mountains.jpg');

// Upload the file and metadata
const uploadTask = uploadBytesResumable(storageRef, file);

// Pause the upload
uploadTask.pause();

// Resume the upload
uploadTask.resume();

// Cancel the upload
uploadTask.cancel();
storage_manage_uploads.js

Web

// Upload the file and metadata
var uploadTask = storageRef.child('images/mountains.jpg').put(file);

// Pause the upload
uploadTask.pause();

// Resume the upload
uploadTask.resume();

// Cancel the upload
uploadTask.cancel();
upload-files.js

监控上传进度

上传时，上传任务可以在 state_changed 观察者 (observer) 中引发进度事件，如：

事件类型	典型用法
running	此事件在任务开始或恢复上传时触发，通常与 pause 事件结合使用。对于较大的上传作业，此事件可能会随着进度更新多次触发。
pause	每次上传被暂停时，此事件都会触发，通常与 running 事件结合使用。

当有事件发生时，系统将传回 TaskSnapshot 对象。此快照是事件发生时任务的视图，该视图不可改变。 此对象包含以下属性：

属性	类型	说明
bytesTransferred	Number	截取快照时已传输的总字节数。
totalBytes	Number	预期应上传的总字节数。
state	firebase.storage.TaskState	上传的当前状态。
metadata	firebaseStorage.Metadata	上传完成前，表示已发送到服务器的元数据。上传完成后，表示服务器发回的元数据。
task	firebaseStorage.UploadTask	快照所对应的任务，可用于“暂停”“恢复”或“取消”任务。
ref	firebaseStorage.Reference	此任务的来源引用。

将这些状态变化与 TaskSnapshot 的属性相结合，即可为监控上传事件提供一种简单而又强大的方法。

Web

import { getStorage, ref, uploadBytesResumable, getDownloadURL } from "firebase/storage";

const storage = getStorage();
const storageRef = ref(storage, 'images/rivers.jpg');

const uploadTask = uploadBytesResumable(storageRef, file);

// Register three observers:
// 1. 'state_changed' observer, called any time the state changes
// 2. Error observer, called on failure
// 3. Completion observer, called on successful completion
uploadTask.on('state_changed', 
  (snapshot) => {
    // Observe state change events such as progress, pause, and resume
    // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
    const progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case 'paused':
        console.log('Upload is paused');
        break;
      case 'running':
        console.log('Upload is running');
        break;
    }
  }, 
  (error) => {
    // Handle unsuccessful uploads
  }, 
  () => {
    // Handle successful uploads on complete
    // For instance, get the download URL: https://firebasestorage.googleapis.com/...
    getDownloadURL(uploadTask.snapshot.ref).then((downloadURL) => {
      console.log('File available at', downloadURL);
    });
  }
);
storage_monitor_upload.js

Web

var uploadTask = storageRef.child('images/rivers.jpg').put(file);

// Register three observers:
// 1. 'state_changed' observer, called any time the state changes
// 2. Error observer, called on failure
// 3. Completion observer, called on successful completion
uploadTask.on('state_changed', 
  (snapshot) => {
    // Observe state change events such as progress, pause, and resume
    // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
    var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case firebase.storage.TaskState.PAUSED: // or 'paused'
        console.log('Upload is paused');
        break;
      case firebase.storage.TaskState.RUNNING: // or 'running'
        console.log('Upload is running');
        break;
    }
  }, 
  (error) => {
    // Handle unsuccessful uploads
  }, 
  () => {
    // Handle successful uploads on complete
    // For instance, get the download URL: https://firebasestorage.googleapis.com/...
    uploadTask.snapshot.ref.getDownloadURL().then((downloadURL) => {
      console.log('File available at', downloadURL);
    });
  }
);
upload-files.js

错误处理

导致上传时出错的原因有很多，包括本地文件不存在，或者用户不具备上传相应文件的权限。如需了解有关错误的详细信息，请参阅文档的处理错误部分。

完整示例

下面是一个包含进度监控和错误处理的完整上传示例：

Web

import { getStorage, ref, uploadBytesResumable, getDownloadURL } from "firebase/storage";

const storage = getStorage();

// Create the file metadata
/** @type {any} */
const metadata = {
  contentType: 'image/jpeg'
};

// Upload file and metadata to the object 'images/mountains.jpg'
const storageRef = ref(storage, 'images/' + file.name);
const uploadTask = uploadBytesResumable(storageRef, file, metadata);

// Listen for state changes, errors, and completion of the upload.
uploadTask.on('state_changed',
  (snapshot) => {
    // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
    const progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case 'paused':
        console.log('Upload is paused');
        break;
      case 'running':
        console.log('Upload is running');
        break;
    }
  }, 
  (error) => {
    // A full list of error codes is available at
    // https://firebase.google.com/docs/storage/web/handle-errors
    switch (error.code) {
      case 'storage/unauthorized':
        // User doesn't have permission to access the object
        break;
      case 'storage/canceled':
        // User canceled the upload
        break;

      // ...

      case 'storage/unknown':
        // Unknown error occurred, inspect error.serverResponse
        break;
    }
  }, 
  () => {
    // Upload completed successfully, now we can get the download URL
    getDownloadURL(uploadTask.snapshot.ref).then((downloadURL) => {
      console.log('File available at', downloadURL);
    });
  }
);
storage_upload_handle_error.js

Web

// Create the file metadata
var metadata = {
  contentType: 'image/jpeg'
};

// Upload file and metadata to the object 'images/mountains.jpg'
var uploadTask = storageRef.child('images/' + file.name).put(file, metadata);

// Listen for state changes, errors, and completion of the upload.
uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED, // or 'state_changed'
  (snapshot) => {
    // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
    var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case firebase.storage.TaskState.PAUSED: // or 'paused'
        console.log('Upload is paused');
        break;
      case firebase.storage.TaskState.RUNNING: // or 'running'
        console.log('Upload is running');
        break;
    }
  }, 
  (error) => {
    // A full list of error codes is available at
    // https://firebase.google.com/docs/storage/web/handle-errors
    switch (error.code) {
      case 'storage/unauthorized':
        // User doesn't have permission to access the object
        break;
      case 'storage/canceled':
        // User canceled the upload
        break;

      // ...

      case 'storage/unknown':
        // Unknown error occurred, inspect error.serverResponse
        break;
    }
  }, 
  () => {
    // Upload completed successfully, now we can get the download URL
    uploadTask.snapshot.ref.getDownloadURL().then((downloadURL) => {
      console.log('File available at', downloadURL);
    });
  }
);
upload-files.js

现在您已经上传了文件，接下来，我们将学习如何从 Cloud Storage 下载文件。