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

Besides the solution using the FileProvider, there is another way to work around this. Simply put

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

in Application.onCreate(). In this way the VM ignores the file URI exposure.

Method

builder.detectFileUriExposure()

enables the file exposure check, which is also the default behavior if we don't setup a VmPolicy.

I encountered a problem that if I use a content:// URI to send something, some apps just can't understand it. And downgrading the target SDK version is not allowed. In this case my solution is useful.

Update:

As mentioned in the comment, StrictMode is diagnostic tool, and is not supposed to be used for this problem. When I posted this answer a year ago, many apps can only receive File uris. They just crash when I tried to send a FileProvider uri to them. This is fixed in most apps now, so we should go with the FileProvider solution.

Answer 2

First you need to add a provider to your AndroidManifest

  <application
    ...>
    <activity>
    .... 
    </activity>
    <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.your.package.fileProvider"
        android:grantUriPermissions="true"
        android:exported="false">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>
  </application>

now create a file in xml resource folder (if using android studio you can hit Alt + Enter after highlighting file_paths and select create a xml resource option)

Next in the file_paths file enter

<?xml version="1.0" encoding="utf-8"?>
<paths>
  <external-path path="Android/data/com.your.package/" name="files_root" />
  <external-path path="." name="external_storage_root" />
</paths>

This example is for external-path you can refere here for more options. This will allow you to share files which are in that folder and its sub-folder.

Now all that's left is to create the intent as follows:

    MimeTypeMap mime = MimeTypeMap.getSingleton();
    String ext = newFile.getName().substring(newFile.getName().lastIndexOf(".") + 1);
    String type = mime.getMimeTypeFromExtension(ext);
    try {
        Intent intent = new Intent();
        intent.setAction(Intent.ACTION_VIEW);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            Uri contentUri = FileProvider.getUriForFile(getContext(), "com.your.package.fileProvider", newFile);
            intent.setDataAndType(contentUri, type);
        } else {
            intent.setDataAndType(Uri.fromFile(newFile), type);
        }
        startActivityForResult(intent, ACTIVITY_VIEW_ATTACHMENT);
    } catch (ActivityNotFoundException anfe) {
        Toast.makeText(getContext(), "No activity found to open this attachment.", Toast.LENGTH_LONG).show();
    }

EDIT: I added the root folder of the sd card in the file_paths. I have tested this code and it does work.

Answer 3

I used Palash's answer given above but it was somewhat incomplete, I had to provide permission like this

Intent intent = new Intent(Intent.ACTION_VIEW);
    Uri uri;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        uri = FileProvider.getUriForFile(this, getPackageName() + ".provider", new File(path));

        List<ResolveInfo> resInfoList = getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo resolveInfo : resInfoList) {
            String packageName = resolveInfo.activityInfo.packageName;
            grantUriPermission(packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
        }
    }else {
        uri = Uri.fromFile(new File(path));
    }

    intent.setDataAndType(uri, "application/vnd.android.package-archive");

    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    startActivity(intent);

Answer 4

If targetSdkVersion is higher than 24, then FileProvider is used to grant access.

Create an xml file(Path: res\xml) provider_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="external_files" path="."/>
</paths>

Add a Provider in AndroidManifest.xml

    <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"/>
    </provider>

and replace

Uri uri = Uri.fromFile(fileImagePath);

to

Uri uri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID + ".provider",fileImagePath);

and you are good to go. Hope it helps.

Answer 5

For downloading pdf from server , add below code in your service class. Hope this is helpful for you.

File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), fileName + ".pdf");
    intent = new Intent(Intent.ACTION_VIEW);
    //Log.e("pathOpen", file.getPath());

    Uri contentUri;
    contentUri = Uri.fromFile(file);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);

    if (Build.VERSION.SDK_INT >= 24) {

        Uri apkURI = FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".provider", file);
        intent.setDataAndType(apkURI, "application/pdf");
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

    } else {

        intent.setDataAndType(contentUri, "application/pdf");
    }

And yes , don't forget to add permissions and provider in your manifest.

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

<application

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths" />
    </provider>

</application>