Swift:URLSessionDownload file says it exists but it doesn't?












11















Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question























  • Hey! Did you find any solution for this ? I am having same error.

    – Viral Narshana
    Jul 28 '17 at 15:02











  • any solutions to this?

    – swalkner
    Jul 25 '18 at 12:45











  • I am having a hard time reproducing this, is it possible to attach a working example on github?

    – J. Doe
    Nov 27 '18 at 11:07
















11















Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question























  • Hey! Did you find any solution for this ? I am having same error.

    – Viral Narshana
    Jul 28 '17 at 15:02











  • any solutions to this?

    – swalkner
    Jul 25 '18 at 12:45











  • I am having a hard time reproducing this, is it possible to attach a working example on github?

    – J. Doe
    Nov 27 '18 at 11:07














11












11








11


1






Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question














Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?







ios swift nsurlsession nsurlsessiondownloadtask






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Jul 1 '17 at 19:06









skyguyskyguy

2,57673273




2,57673273













  • Hey! Did you find any solution for this ? I am having same error.

    – Viral Narshana
    Jul 28 '17 at 15:02











  • any solutions to this?

    – swalkner
    Jul 25 '18 at 12:45











  • I am having a hard time reproducing this, is it possible to attach a working example on github?

    – J. Doe
    Nov 27 '18 at 11:07



















  • Hey! Did you find any solution for this ? I am having same error.

    – Viral Narshana
    Jul 28 '17 at 15:02











  • any solutions to this?

    – swalkner
    Jul 25 '18 at 12:45











  • I am having a hard time reproducing this, is it possible to attach a working example on github?

    – J. Doe
    Nov 27 '18 at 11:07

















Hey! Did you find any solution for this ? I am having same error.

– Viral Narshana
Jul 28 '17 at 15:02





Hey! Did you find any solution for this ? I am having same error.

– Viral Narshana
Jul 28 '17 at 15:02













any solutions to this?

– swalkner
Jul 25 '18 at 12:45





any solutions to this?

– swalkner
Jul 25 '18 at 12:45













I am having a hard time reproducing this, is it possible to attach a working example on github?

– J. Doe
Nov 27 '18 at 11:07





I am having a hard time reproducing this, is it possible to attach a working example on github?

– J. Doe
Nov 27 '18 at 11:07












1 Answer
1






active

oldest

votes


















3





+25









Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code





share|improve this answer
























  • For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

    – FranticRock
    Dec 26 '18 at 16:26











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









3





+25









Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code





share|improve this answer
























  • For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

    – FranticRock
    Dec 26 '18 at 16:26
















3





+25









Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code





share|improve this answer
























  • For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

    – FranticRock
    Dec 26 '18 at 16:26














3





+25







3





+25



3




+25





Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code





share|improve this answer













Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code






share|improve this answer












share|improve this answer



share|improve this answer










answered Nov 22 '18 at 14:44









Graham PerksGraham Perks

17.2k64671




17.2k64671













  • For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

    – FranticRock
    Dec 26 '18 at 16:26



















  • For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

    – FranticRock
    Dec 26 '18 at 16:26

















For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

– FranticRock
Dec 26 '18 at 16:26





For me, the status code is 200 here, but the file cannot be found by doing the following: try FileManager.default.copyItem(atPath: location.absoluteString, toPath: ...)

– FranticRock
Dec 26 '18 at 16:26




















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