如何将位图保存到Firebase

Question

我创建了一个简单的应用程序来裁剪图像.现在我想将此图像保存到Fire基座.

photo.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            //Intent imageDownload = new 
Intent(Intent.ACTION_PICK,MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
      Intent imageDownload=new Intent();
      imageDownload.setAction(Intent.ACTION_GET_CONTENT);
      imageDownload.setType("image/*");
      imageDownload.putExtra("crop", "true");
      imageDownload.putExtra("aspectX", 1);
      imageDownload.putExtra("aspectY", 1);
      imageDownload.putExtra("outputX", 200);
      imageDownload.putExtra("outputY", 200);
      imageDownload.putExtra("return-data", true);
      startActivityForResult(imageDownload, GALLERY_REQUEST_CODE);


        }
    });
 }
  @Override
protected void onActivityResult(int requestCode, int resultCode, Intent 
  data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == GALLERY_REQUEST_CODE && resultCode == RESULT_OK && 
   data != null) {
        Bundle extras = data.getExtras();
        image = extras.getParcelable("data");
        photo.setImageBitmap(image);

   }






}

如何将此图像保存到Firebase.我尝试了很多教程,但没能成功.请用简单的代码验证.

Answer 1

您必须先将Firebase存储的依赖项添加到build.gradle文件中:

compile 'com.google.firebase:firebase-storage:10.0.1'
compile 'com.google.firebase:firebase-auth:10.0.1'

然后创建一个FirebaseStorage实例:

FirebaseStorage storage = FirebaseStorage.getInstance();

要将文件上载到Firebase存储,首先要创建对文件完整路径的引用,包括文件名.

// Create a storage reference from our app
StorageReference storageRef = storage.getReferenceFromUrl("gs://<your-bucket-name>");

// Create a reference to "mountains.jpg"
StorageReference mountainsRef = storageRef.child("mountains.jpg");

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

// While the file names are the same, the references point to different files
mountainsRef.getName().equals(mountainImagesRef.getName());    // true
mountainsRef.getPath().equals(mountainImagesRef.getPath());    // false

一旦创建了适当的引用,就可以调用putBytes(),putFile()或putStream()方法将文件上载到Firebase存储.

putBytes()方法是将文件上传到Firebase存储的最简单方法.putBytes()接受一个byte []并返回一个UploadTask,您可以使用它来管理和监控上传的状态.

// Get the data from an ImageView as bytes
imageView.setDrawingCacheEnabled(true);
imageView.buildDrawingCache();
Bitmap bitmap = imageView.getDrawingCache();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] data = baos.toByteArray();

UploadTask uploadTask = mountainsRef.putBytes(data);
uploadTask.addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(@NonNull Exception exception) {
        // Handle unsuccessful uploads
    }
}).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
    @Override
    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
        // taskSnapshot.getMetadata() contains file metadata such as size, content-type, and download URL.
        Uri downloadUrl = taskSnapshot.getDownloadUrl();
    }
});

Answer 2

Firebase不支持二进制数据，因此需要将图像数据转换为base64或使用Firebase Storage

方法一（推荐）

 sref = FirebaseStorage.getInstance().getReference(); // please go to above link and setup firebase storage for android

 public void uploadFile(Uri imagUri) {
    if (imagUri != null) {

        final StorageReference imageRef = sref.child("android/media") // folder path in firebase storage
                .child(imagUri.getLastPathSegment());

        photoRef.putFile(imagUri)
                .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot snapshot) {
                        // Get the download URL
                        Uri downloadUri = snapshot.getMetadata().getDownloadUrl();
                        // use this download url with imageview for viewing & store this linke to firebase message data

                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception exception) {
                         // show message on failure may be network/disk ?
                    }
                });
    }
}

方法2

对于小图像，我们仍然可以使用此解决方案，Firebase 字段值有限制（1MB 字段值），请查看官方文档了解详细信息

public void getImageData(Bitmap bmp) {  

  ByteArrayOutputStream bao = new ByteArrayOutputStream();
  bmp.compress(Bitmap.CompressFormat.PNG, 100, bao); // bmp is bitmap from user image file
  bmp.recycle();
  byte[] byteArray = bao.toByteArray();
  String imageB64 = Base64.encodeToString(byteArray, Base64.URL_SAFE); 
  //  store & retrieve this string which is URL safe(can be used to store in FBDB) to firebase
  // Use either Realtime Database or Firestore
  }