android.os.FileUriExposedException: file:///storag

Question

The app is crashing when I'm trying to open a file. It works below Android Nougat, but on Android Nougat it crashes. It only crashes when I try to open a file from the SD card, not from the system partition. Some permission problem?

Sample code:

File file = new File("/storage/emulated/0/test.txt");
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), "text/*");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent); // Crashes on this line

Log:

android.os.FileUriExposedException: file:///storage/emulated/0/test.txt exposed beyond app through Intent.getData()

Edit:

When targeting Android Nougat, file:// URIs are not allowed anymore. We should use content:// URIs instead. However, my app needs to open files in root directories. Any ideas?

Answer 1

Just paste the below code in activity onCreate()

StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder(); StrictMode.setVmPolicy(builder.build());

It will ignore URI exposure

Happy coding :-)

Answer 2

Xamarin.Android

Note: The path xml/provider_paths.xml (.axml) couldn't be resolved, even after making the xml folder under Resources (maybe it can be put in an existing location like Values, didn't try), so I resorted to this which works for now. Testing showed that it only needs to be called once per application run (which makes sense being that it changes the operational state of the host VM).

Note: xml needs to be capitalized, so Resources/Xml/provider_paths.xml

Java.Lang.ClassLoader cl = _this.Context.ClassLoader;
Java.Lang.Class strictMode = cl.LoadClass("android.os.StrictMode");                
System.IntPtr ptrStrictMode = JNIEnv.FindClass("android/os/StrictMode");
var method = JNIEnv.GetStaticMethodID(ptrStrictMode, "disableDeathOnFileUriExposure", "()V");                
JNIEnv.CallStaticVoidMethod(strictMode.Handle, method);

Answer 3

My Solution was to 'Uri.parse' the File Path as String, instead of using Uri.fromFile().

String storage = Environment.getExternalStorageDirectory().toString() + "/test.txt";
File file = new File(storage);
Uri uri;
if (Build.VERSION.SDK_INT < 24) {
    uri = Uri.fromFile(file);
} else {
    uri = Uri.parse(file.getPath()); // My work-around for new SDKs, causes ActivityNotFoundException in API 10.
}
Intent viewFile = new Intent(Intent.ACTION_VIEW);
viewFile.setDataAndType(uri, "text/plain");
startActivity(viewFile);

Seems that fromFile() uses A file pointer, which I suppose could be insecure when memory addresses are exposed to all apps. But A file path String never hurt anybody, so it works without throwing FileUriExposedException.

Tested on API levels 9 to 26! Does not require FileProvider, nor the Android Support Library at all.

Answer 4

In my case I got rid of the exception by replacing SetDataAndType with just SetData.

Answer 5

If your targetSdkVersion is 24 or higher, you can not use file: Uri values in Intents on Android 7.0+ devices.

Your choices are:

1. Drop your targetSdkVersion to 23 or lower, or

2. Put your content on internal storage, then use FileProvider to make it available selectively to other apps

For example:

Intent i=new Intent(Intent.ACTION_VIEW, FileProvider.getUriForFile(this, AUTHORITY, f));

i.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(i);

(from this sample project)

Answer 6

Using the fileProvider is the way to go. But you can use this simple workaround:

WARNING: It will be fixed in next Android release - https://issuetracker.google.com/issues/37122890#comment4

replace:

startActivity(intent);

by

startActivity(Intent.createChooser(intent, "Your title"));