如何从Firebase存储获取URL getDownloadURL

提问者：小点点

如何从Firebase存储获取URL getDownloadURL

我正在尝试获得“长期持久下载链接”到我们的Firebase存储桶中的文件。我已将其权限更改为

service firebase.storage {
  match /b/project-xxx.appspot.com/o {
    match /{allPaths=**} {
      allow read, write;
    }
  }
}

我的javacode如下所示:

private String niceLink (String date){
    String link;
    // Points to the root reference
    StorageReference storageRef = FirebaseStorage.getInstance().getReference();
    StorageReference dateRef = storageRef.child("/" + date+ ".csv");
    link = dateRef.getDownloadUrl().toString();
    return link;
}

当我运行这个时，我得到了类似于com.google.android.gms.tasks.zzh@xxx的uri链接

问题1。我是否可以从中获得类似以下内容的下载链接:https://firebasestorage.googleapis.com/v0/b/project-xxxx.appspot.com/o/20-5-2016.csv？alt=media&token=b5d45a7f-3ab7-4f9b-b661-3a2187adxxxx

在尝试获取上面的链接时，我更改了返回前的最后一行，如下所示:

private String niceLink (String date){
    String link;
    // Points to the root reference
    StorageReference storageRef = FirebaseStorage.getInstance().getReference();
    StorageReference dateRef = storageRef.child("/" + date+ ".csv");
    link = dateRef.getDownloadUrl().getResult().toString();
    return link;
}

但这样做时，我得到一个403错误，应用程序崩溃。 consol告诉我这是bc用户未登录/auth。 “请先登录再索取令牌”

问题2。我该怎么解决这个问题？

共3个答案

匿名用户

请参考文档获取下载URL。

当您调用GetDownloadUrl()时，调用是异步的，并且您必须在成功回调时进行订阅才能获得结果:

// Calls the server to securely obtain an unguessable download Url
private void getUrlAsync (String date){
    // Points to the root reference
    StorageReference storageRef = FirebaseStorage.getInstance().getReference();
    StorageReference dateRef = storageRef.child("/" + date+ ".csv");
    dateRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>()
    {
        @Override
        public void onSuccess(Uri downloadUrl) 
        {                
           //do something with downloadurl
        } 
    });
}

这将返回一个不可猜测的公共下载URL。如果您刚刚上传了一个文件，这个公共url将在上传的成功回调中（上传之后不需要调用另一个异步方法）。

但是，如果您所需要的只是引用的string表示，则只需调用.toString()即可

// Returns a Uri of the form gs://bucket/path that can be used
// in future calls to getReferenceFromUrl to perform additional
// actions
private String niceRefLink (String date){
    // Points to the root reference
    StorageReference storageRef = FirebaseStorage.getInstance().getReference();
    StorageReference dateRef = storageRef.child("/" + date+ ".csv");
    return dateRef.toString();
}

匿名用户

//FireBase存储-易于上传和下载。

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable final Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == RC_SIGN_IN){
        if(resultCode == RESULT_OK){
            Toast.makeText(this,"Signed in!", LENGTH_SHORT).show();
        } else if(resultCode == RESULT_CANCELED){
            Toast.makeText(this,"Signed in canceled!", LENGTH_SHORT).show();
            finish();
        }
    } else if(requestCode == RC_PHOTO_PICKER && resultCode == RESULT_OK){

        // HERE I CALLED THAT METHOD
        uploadPhotoInFirebase(data);

    }
}

private void uploadPhotoInFirebase(@Nullable Intent data) {
    Uri selectedImageUri = data.getData();

    // Get a reference to store file at chat_photos/<FILENAME>
    final StorageReference photoRef = mChatPhotoStorageReference
                    .child(selectedImageUri
                    .getLastPathSegment());

    // Upload file to Firebase Storage
    photoRef.putFile(selectedImageUri)
            .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {

                    // Download file From Firebase Storage
                    photoRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                        @Override
                        public void onSuccess(Uri downloadPhotoUrl) {
                            //Now play with downloadPhotoUrl
                            //Store data into Firebase Realtime Database
                            FriendlyMessage friendlyMessage = new FriendlyMessage
                                    (null, mUsername, downloadPhotoUrl.toString());
                            mDatabaseReference.push().setValue(friendlyMessage);
                        }
                    });
                }
            });
}

匿名用户

在这里我是上传和获取图像的url同时。。。

           final StorageReference profileImageRef = FirebaseStorage.getInstance().getReference("profilepics/" + System.currentTimeMillis() + ".jpg");

            if (uriProfileImage != null) {

            profileImageRef.putFile(uriProfileImage)
                        .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                            @Override
                            public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                               // profileImageUrl taskSnapshot.getDownloadUrl().toString(); //this is depreciated

                          //this is the new way to do it
                   profileImageRef.getDownloadUrl().addOnCompleteListener(new OnCompleteListener<Uri>() {
                                    @Override
                                    public void onComplete(@NonNull Task<Uri> task) {
                                       String profileImageUrl=task.getResult().toString();
                                        Log.i("URL",profileImageUrl);
                                    }
                                });
                            }
                        })
                        .addOnFailureListener(new OnFailureListener() {
                            @Override
                            public void onFailure(@NonNull Exception e) {
                                progressBar.setVisibility(View.GONE);
                                Toast.makeText(ProfileActivity.this, "aaa "+e.getMessage(), Toast.LENGTH_SHORT).show();
                            }
                        });
            }