我在该网站上看到了类似的问题，但是大多数问题与获取单个上载图像的下载URL有关。从这些帖子中寻求帮助，现在我可以获得单个图像的下载URL。
但是当我尝试获取一起上传的多个图像的下载URL时，我遇到了一个问题。我想做三件事...
1。选择三张图片2.将它们上传到Firebase Cloud Storage3.获取上载图像的URL，并将其保存在ArrayList中。
我可以成功地完成前两件事，但是还没有实现第三件事。当我单击“更新”按钮时，所有图像均完美存储在Cloud Storage中，但在请求所有图像的下载URL时显示错误。
这里是单击“更新”按钮时的代码：
upload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
progressDialog.setMessage("Uploading .... ");
progressDialog.show();
storageReference = FirebaseStorage.getInstance().getReference().child("Pictures");
int uploadCount = 0;
// imageList is an ArrayList<Uri> which holds the address of selected 3 images.
// imageAddress is an ArrayList<String> where I want to save all downloadUrls of images (each url is saved as a string).
// imagePath is a StorageReference
while(uploadCount < imageList.size()) {
Log.d("UploadCount", uploadCount+"");
Uri uri_Image = imageList.get(uploadCount);
imagePath = storageReference.child(uri_Image.getLastPathSegment());
imagePath.putFile(uri_Image).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
imagePath.getDownloadUrl().addOnSuccessListener(newOnSuccessListener<Uri>() {
@Override
public void onSuccess(Uri uri) {
Uri downloadUri = uri;
imageAddress.add(downloadUri.toString());
Log.d("ImageAddress Size: ", imageAddress.size()+"");
}
});
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(SignOutActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
progressDialog.dismiss();
}
}); //.............
if(uploadCount == (imageList.size()-1)) {
Log.d("Good", "HELLO HELLO");
Toast.makeText(SignOutActivity.this, "Successfully Uploaded", Toast.LENGTH_LONG).show();
upload.setClickable(false);
progressDialog.dismiss();
}
else {
Log.d("BAD", "NOT HELLO "+uploadCount);
}
uploadCount = uploadCount + 1;
}
}
});
这里是错误：
2020-02-15 17:02:26.945 28207-28735/com.example.practiceapplication E/StorageException: StorageException has occurred.
Object does not exist at location.
Code: -13010 HttpResult: 404
2020-02-15 17:02:26.946 28207-28735/com.example.practiceapplication E/StorageException: {"error": {"code": 404, "message": "Not Found. Could not get object", "status": "GET_OBJECT"}}
java.io.IOException: {"error": {"code": 404, "message": "Not Found. Could not get object", "status": "GET_OBJECT"}}
at com.google.firebase.storage.network.NetworkRequest.parseResponse(com.google.firebase:firebase-storage@@19.1.1:433)
at com.google.firebase.storage.network.NetworkRequest.parseErrorResponse(com.google.firebase:firebase-storage@@19.1.1:450)
at com.google.firebase.storage.network.NetworkRequest.processResponseStream(com.google.firebase:firebase-storage@@19.1.1:441)
at com.google.firebase.storage.network.NetworkRequest.performRequest(com.google.firebase:firebase-storage@@19.1.1:272)
at com.google.firebase.storage.network.NetworkRequest.performRequest(com.google.firebase:firebase-storage@@19.1.1:286)
at com.google.firebase.storage.internal.ExponentialBackoffSender.sendWithExponentialBackoff(com.google.firebase:firebase-storage@@19.1.1:70)
at com.google.firebase.storage.internal.ExponentialBackoffSender.sendWithExponentialBackoff(com.google.firebase:firebase-storage@@19.1.1:62)
at com.google.firebase.storage.GetDownloadUrlTask.run(com.google.firebase:firebase-storage@@19.1.1:76)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
2020-02-15 17:02:30.712 28207-28207/com.example.practiceapplication D/ImageAddress Size:: 1
如果有人告诉我更正，这将对我非常有帮助。谢谢
您的代码在处理异步代码和for循环时遇到了混合使用局部变量和共享全局变量的问题。
在上面的代码中，在for循环内使用全局变量imagePath，imageAddress和imageList，这最终是导致该异常的关键原因。
单击upload按钮时，代码将执行以下步骤，并以粗体显示错误：
imagePath的值以指向该图像的上载位置"NOT HELLO 0"imagePath的值以指向该图像的上载位置"NOT HELLO 1"imagePath的值以指向该图像的上载位置"HELLO HELLO"和祝酒"Successfully Uploaded"（尚未实际完成）StorageException]] >>第二张图像完成上传StorageException）] >>第三张图片完成上传imageList的局部变量副本storageReference使用局部变量imagePath，然后重命名为imageRef以准确反映其类型imageAddress重命名为imageAddressList以准确反映其类型（推荐）while()循环并改为使用for迭代器imageAddressList，而不是异步更新。currentUploadTask并将其绑定到视图对话框/通知以显示文件上传进度upload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
progressDialog.setMessage("Uploading .... ");
progressDialog.show();
upload.setClickable(false); // disable upload button whilst uploading
final StorageReference storageReference = FirebaseStorage.getInstance().getReference().child("Pictures");
final List<Uri> clonedImageList = new ArrayList<>(imageList);
imageList.clear(); // empty old list?
int imageListSize = clonedImageList.size();
List<Task<Uri>> uploadedImageUrlTasks = new ArrayList<>(imageListSize);
for (Uri imageUri : clonedImageList) {
final String imageFilename = imageUri.getLastPathSegment();
Log.d("upload.onClick()", "Starting upload for \"" + imageFilename + "\"...");
StorageReference imageRef = storageReference.child(imageFilename); // Warning: potential for collisions/overwrite
UploadTask currentUploadTask = imageRef.putFile(imageUri);
Task<Uri> currentUrlTask = currentUploadTask
.continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
@Override
public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
if (!task.isSuccessful()) {
Log.d("upload.onClick()", "Upload for \"" + imageFilename + "\" failed!");
throw task.getException(); // rethrow any errors
}
Log.d("upload.onClick()", "Upload for \"" + imageFilename + "\" finished. Fetching download URL...");
return imageRef.getDownloadUrl();
}
})
.continueWithTask(new Continuation<Uri, Uri>() { // purely for logging to debug, recommended to remove
@Override
public Task<Uri> then(@NonNull Task<Uri> task) throws Exception {
if (!task.isSuccessful()) {
Log.d("upload.onClick()", "Could not get download URL for \"" + imageFilename + "\"!");
throw task.getException(); // rethrow any errors
}
Log.d("upload.onClick()", "Download URL for \"" + imageFilename + "\" is \"" + task.getResult() + "\".");
return task.getResult();
}
});
uploadedImageUrlTasks.add(currentUrlTask);
}
// At this point, all the files are being uploaded in parallel
// Each upload is tracked by the tasks in uploadedImageUrlTasks
Tasks.whenAllComplete(uploadedImageUrlTasks)
.addOnCompleteListener(new OnCompleteListener<List<Task<Uri>>>() {
@Override
public void onComplete(@NonNull List<Task<Uri>> tasks) {
int tasksCount = tasks.size();
List<Uri> failedUploads = new ArrayList<>();
imageAddressList.clear(); // empty old entries?
for (Task<Uri> task : tasks) {
if (task.isSuccessful()) {
successCount++;
Uri downloadUri = task.getResult();
imageAddressList.add(downloadUri.toString());
} else {
Uri imageUri = clonedImageList.get(tasks.indexOf(task));
failedUploads.add(imageUri);
Log.e("upload.onClick()", "Failed to upload/fetch URL for \"" + imageUri.getLastPathSegment() + "\" with exception", task.getException()); // log exception
}
}
progressDialog.dismiss(); // dismiss upload dialog
if (failedUploads.size() > 0) {
Toast.makeText(SignOutActivity.this, failedUploads.size() + "/" + tasksCount + " uploads failed.", Toast.LENGTH_LONG).show();
// TODO: Do something with list of failed uploads such as readd to the now empty upload list
imageList.addAll(failedUploads);
upload.setClickable(true);
} else {
Toast.makeText(SignOutActivity.this, "Successfully uploaded all " + tasksCount + " files.", Toast.LENGTH_LONG).show();
}
// TODO: Now that imageAddressList has been updated, update the UI - e.g tell recycler view to refresh
}
});
}
});