getDownloadUrl函数不返回正确的url

Question

我正在将pdf上传到Firebase存储，并希望获得其下载网址。我使用以下代码：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case 1212:
            if (resultCode == RESULT_OK) {
                String FilePath = data.getDataString();
                t.setText(FilePath);
                Uri pdfuri = data.getData();
                final StorageReference mp = mpdf.child("pdf").child(random()+".pdf");
                mp.putFile(pdfuri).addOnCompleteListener(new OnCompleteListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onComplete(@NonNull Task<UploadTask.TaskSnapshot> task) {
                        if(task.isSuccessful())
                        {
                            String download_url = task.getResult().getMetadata().getReference().getDownloadUrl().toString();
                            String parent = getIntent().getStringExtra("type").toString();
                            String ch = getIntent().getStringExtra("value").toString();
                            GeologicDatabase.modifySingle(parent,ch,download_url);
                            Toast.makeText(modifypdf.this,download_url , Toast.LENGTH_SHORT).show();
                            finish();
                        }
                        else {
                            Toast.makeText(modifypdf.this,"Faild" , Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
            break;
    }
    super.onActivityResult(requestCode, resultCode, data);
}

这条线的结果

String download_url = task.getResult().getMetadata().getReference().getDownloadUrl().toString();

是“com.google.android.gms.tasks.zzu@7f93358”不是正确的网址

---

该问题的解决方案是使用上传任务，并在其完整侦听器中编写代码，将任务结果作为Uri并将其转换为字符串

final String name = random() + ".pdf";
                dp = mpdf.child("pdf").child(name);
                UploadTask uploadTask = dp.putFile(pdfuri);
                Task<Uri> urlTask = uploadTask.continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
                    @Override
                    public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
                        if (!task.isSuccessful()) {
                            throw task.getException();
                        }

                        // Continue with the task to get the download URL
                        return dp.getDownloadUrl();
                    }
                }).addOnCompleteListener(new OnCompleteListener<Uri>() {
                    @Override
                    public void onComplete(@NonNull Task<Uri> task) {
                        if (task.isSuccessful()) {
                            tt = title.getText().toString();
                            Uri downloadUri = task.getResult();
                            String download_url = downloadUri.toString();
                            String parent = getIntent().getStringExtra("type").toString();
                            String ch = getIntent().getStringExtra("value").toString();
                            GeologicDatabase.updateChild(parent, ch, "url",download_url,tt);
                            GeologicDatabase.updateChild(parent,ch,"name",name,tt);
                            Toast.makeText(addpdf.this, download_url, Toast.LENGTH_SHORT).show();
                            finish();
                        } else {
                            // Handle failures
                            // ...
                        }
                    }
                });

Answer 1

getDownloadUrl()不返回URL。从the javadoc可以看出，它返回一个产生URL的Task。您必须等待此任务完成才能获得最终的URL。

Answer 2

//试一下

Task<Uri> newTask = task.getResult().getMetadata().getReference().getDownloadUrl();
            newTask.addOnSuccessListener(new OnSuccessListener<Uri>() {
                @Override
                public void onSuccess(Uri uri) {
                    yourUriVariable= uri;
                }
            });