Class Cast exception

[learnyst]

• please provide the version of installed library and RN project.
  React native: 0.60.4
  rnFetchBlob: 0.11.2

• a sample code snippet/repository is very helpful to spotting the problem.
  We are not able to reproduce crash. Many of app users are facing issue.

rnFetchBlob is crashing with the below exception. We have got this exception in bugsnag

java.lang.ClassCastException okhttp3.internal.http.RealResponseBody cannot be cast to com.RNFetchBlob.Response.RNFetchBlobFileResp
RNFetchBlobReq.java:544 com.RNFetchBlob.RNFetchBlobReq.done
RNFetchBlobReq.java:67 com.RNFetchBlob.RNFetchBlobReq.access$100
RNFetchBlobReq.java:445 com.RNFetchBlob.RNFetchBlobReq$3.onResponse
RealCall.java:174 okhttp3.RealCall$AsyncCall.execute
NamedRunnable.java:32 okhttp3.internal.NamedRunnable.run
ThreadPoolExecutor.java:1113 java.util.concurrent.ThreadPoolExecutor.runWorker
ThreadPoolExecutor.java:588 java.util.concurrent.ThreadPoolExecutor$Worker.run
Thread.java:818 java.lang.Thread.run

[z384647062]

Change RNFetchBlob.fs.dirs.MusicDir to RNFetchBlob.fs.dirs.DocumentDir in option path of RNFetchBlob.config helps me solve the problem

[oleksandr-dziuban]

Change RNFetchBlob.fs.dirs.MusicDir to RNFetchBlob.fs.dirs.DocumentDir in option path of RNFetchBlob.config helps me solve the problem

@z384647062 I have same issue, but don't use any RNFetchBlob.fs.dirs.MusicDir in app.

I use RNFetchBlob.fs.dirs.DocumentDir everywhere.
Inеeresting that this error is only throws on non-clean Android. On Native Android (simulator or device) everything is OK. On Xiaomi, for example I see this error in MiUI

[oleksandr-dziuban]

Question to maintainers, Is it possible to review this issue please?

[oleksandr-dziuban]

@Traviskn Hello, I have checked this issues in 0.10.16 and it is not reproducible!
Only the latest few versions throw this error for Android

[oleksandr-dziuban]

Any ideas guys?

[Sumit-Chakole]

Change RNFetchBlob.fs.dirs.MusicDir to RNFetchBlob.fs.dirs.DocumentDir in option path of RNFetchBlob.config helps me solve the problem

This worked in my case too :)

[brianinator]

Relates to recent PR #530 that is going to catch it and return back.

[olcayertas]

I am getting the same error on Mac OS X with Android simulator (API 29 Google Play):

let dir = Platform.OS === "ios" ? 
    RNFetchBlob.fs.dirs.DocumentDir : 
    RNFetchBlob.fs.dirs.DownloadDir;
console.log("Download location: " + dir);
let headers = { Authorization: "Bearer " + token };
let options = { fileCache: true, path : dir + '/file' };
RNFetchBlob.config(options).fetch("GET", url, headers)

Error:

java.lang.ClassCastException: okhttp3.internal.http.RealResponseBody
cannot be cast to com.RNFetchBlob.Response.RNFetchBlobFileResp
	at com.RNFetchBlob.RNFetchBlobReq.done(RNFetchBlobReq.java:594)
	at com.RNFetchBlob.RNFetchBlobReq.access$100(RNFetchBlobReq.java:72)
	at com.RNFetchBlob.RNFetchBlobReq$3.onResponse(RNFetchBlobReq.java:493)
	at okhttp3.RealCall$AsyncCall.execute(RealCall.java:206)
	at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
	at java.lang.Thread.run(Thread.java:919)

Version: 0.12.0
React: 0.61.5

[nobady90]

same error in Xiaomi with android 9 and MIUI Global 11.3.4.
in practice it seems that it does not resolve the gallery and therefore does not open the downloaded file with: RNFetchBlob.android.actionViewIntent (res.path (), item.mimeType);

instead everything works normally for example with pdf ... any help?

[hadare1]

I have the same issue on Pixel 3 and,
where do I need to make this change?

Change RNFetchBlob.fs.dirs.MusicDir to RNFetchBlob.fs.dirs.DocumentDir in option path of RNFetchBlob.config helps me solve the problem

This worked in my case too :)

[funkyfourier]

I am having this issue too. If I catch the exception, like in PR #530, then it will just fail silently and not download and save the file.

I am trying to download lots of files at once. They are for the most part slippy map tiles, in other words tiny png files. I slice the list of files in portions, so I do for example 20 at a time with Promise.all. Then I will get maybe 3-4 ClassCastExceptions for about 800 files.

Noticeably, the ClassCastException is not thrown when I only do Promise.all with one promise at a time. If I do two or more, the exception almost certainly will be thrown during those 800 files.

So, to be clear, I have an array of promises, about 800 of them, like this:

const fetchFile = (fileMeta) => {
        return new Promise((resolve, reject) => {
            fetchBlobTask = RNFetchBlob.config({
                path: fileMeta.filename,
                fileCache: true,
            }).fetch(
                'GET', encodeURI(fileMeta.url)
            );
            fetchBlobTask.then((result) => {
                resolve(result);
            }).catch((error) => {
                reject(error);
            });
        });
}

I then do Promise.all on (for example) 20 of those at a time. On iOS this works without a hitch. If I do only one at a time, it works on both platforms, but is painfully slow.

This happens on the emulator, on a OnePlus 6 and on a Sony XZ1.

It is also worth mentioning that the previous version of the app, which was built with Cordova, also had a similar issue on Android.

[brianinator]

Although downgrading to 0.10.16 made this issue go away, I decided to stay on 0.12.0 and switched to use Android download manager. The config I used:

config.addAndroidDownloads = {
  useDownloadManager: true,
  notification: true,
  mediaScannable: false,
  path: /path/to/file
};

[oleksandr-dziuban]

@Traviskn Hello, any ideas how to fix this issue?
Possibly this PR breaks Android
https://github.com/joltup/rn-fetch-blob/pull/530/files

Can we revert it and publish new npm package?

[oleksandr-dziuban]

Is this library still maintained? Looks like no...

[Desintegrator]

same ussue ((( help wanted
Im don't use MusicDir in app

[oleksandr-dziuban]

@Traviskn Is it possible to revert PR related to this issue? We are blocked currently in out project with this issue

[punksta]

I am having the same issue in production app.

[ahetesumspurtree]

Any Update on this issue???
@Traviskn

[nguyenhoanglam]

I think the reason this error occurred is related to Android 10's file access policy. So I temporaryly fixed it by add android:requestLegacyExternalStorage="true" attribute to the application tag in AndroidManifest.xml file, like this:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.android.example">
       ...
    <application
        android:name="com.android.example.MainApplication"
        android:allowBackup="false"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:requestLegacyExternalStorage="true"
        android:theme="@style/AppTheme">
      
        ...
    </application>

</manifest>

[nes123]

@nguyenhoanglam it does not work in my case, and i get the error also for android 9

[Muratoter]

@nguyenhoanglam Worked on Android 10, thanks.

[Yarkhan]

I was getting this error too in some Android devices. Some of the users of my app have denied the app permission to manage files, so when trying to downloading something the app would just crash. Checking the permissions before downloading have fixed this issue for me

Edit: While this fixed the issue for the majority of my users, there are some cases where the problem persists, even when the permissions are correctly set.

I will try to contact the user and send him a custom build using expo filesystem.

[timxyz]

Commenting here even though I can see PR #530 has been merged. I think that PR suppresses the crash but does not address the underlying cause, which is the custom OkHttp interceptor that is installed in RNFetchBlobReq.

This interceptor is responsible for wrapping the response body in an instance of RNFetchBlobDefaultResp. However I've noticed a crash can very occasionally occur like so:

1. An initial request is made that fails with an exception. (e.g. SocketTimeoutException)
2. The HTTP interceptor catches the exception. It has then been written to attempt the request again.
3. If this request then succeeds, then the raw OkHttp response is returned to the caller. The interceptor does not wrap the response body as it is supposed to.
4. The caller is expecting a response with a wrapped body and so crashes.

I have been able to reliably replicate the issue by programatically causing SocketTimeoutException to occur. I am then able to fix by modifying the code to propagate this exception, instead of making a second request. This causes RNFB to properly report a failure back to the RN code. An alternative fix would be to make sure the response from the second request is wrapped, but personally I don't think the interceptor should be implementing this kind of retry logic.

[zhirzh]

This issue exists because the exported dirs constant is populated using getExternalStoragePublicDirectory() which is deprecated in android 10

rn-fetch-blob/android/src/main/java/com/RNFetchBlob/RNFetchBlobFS.java

Lines 250 to 262 in 9110ef2

	static Map<String, Object> getSystemfolders(ReactApplicationContext ctx) {
	Map<String, Object> res = new HashMap<>();
	res.put("DocumentDir", ctx.getFilesDir().getAbsolutePath());
	res.put("CacheDir", ctx.getCacheDir().getAbsolutePath());
	res.put("DCIMDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getAbsolutePath());
	res.put("PictureDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath());
	res.put("MusicDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC).getAbsolutePath());
	res.put("DownloadDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath());
	res.put("MovieDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES).getAbsolutePath());
	res.put("RingtoneDir", Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_RINGTONES).getAbsolutePath());
	String state;
	state = Environment.getExternalStorageState();

[ebrahimmfadae]

I also had this problem in Android 8.1.0 Nexus 5X. Attribute android:requestLegacyExternalStorage="true" didn't fix it but downgrading to 0.10.16 solved the issue. thanks @oleksandr-dziuban

[tastyqbit]

If you install from the master branch using npm install --save git+https://github.com/joltup/rn-fetch-blob.git it has been fixed

[darron1217]

I solved it by following @nguyenhoanglam 's answer for android above 10, and requesting permission for android above 6.
Here's my solution.

Android >= 10

add android:requestLegacyExternalStorage="true" on AndroidManifest.xml

Android >= 6

request permission before fetch

const requestExternalStoragePermissions = async () => {
  const read = await PermissionsAndroid.request(
    PermissionsAndroid.PERMISSIONS.READ_EXTERNAL_STORAGE,
  );
  const write = await PermissionsAndroid.request(
    PermissionsAndroid.PERMISSIONS.WRITE_EXTERNAL_STORAGE,
  );
  return (
    read === PermissionsAndroid.RESULTS.GRANTED &&
    write === PermissionsAndroid.RESULTS.GRANTED
  );
};

[srbulovicdusan]

I solved this problem by modifying rn-fetch-blob and saving those changes permanently using patch-package.

• Go to node_modules/rn-fetch-blob/.../Response/RNFetchBlobFileResp.java and add constructor =>
  public RNFetchBlobFileResp(ResponseBody body) {
  super();
  this.originalBody = body;
  }

• Then find RNFetchBlobReq.java and change line ~594 RNFetchBlobFileResp rnFetchBlobFileResp = (RNFetchBlobFileResp) responseBody; to RNFetchBlobFileResp rnFetchBlobFileResp = new RNFetchBlobFileResp(responseBody);

• Use patch-package to save this changes permanently.

[goldqwert]

This lib not maintained. I used react-native-blob-util properly maintained. It's helped me to fix issues with Class Cast exception.