华为设备上的FileProvider错误 [英] FileProvider error onHuawei devices
问题描述
使用FileProvider.getUriForFile时，我的应用中仅在华为设备上发生例外:
I have an exception that happens only on Huawei devices in my app when using FileProvider.getUriForFile:
Exception: java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/<card name>/Android/data/<app package>/files/.export/2016-10-06 13-22-33.pdf
at android.support.v4.content.FileProvider$SimplePathStrategy.getUriForFile(SourceFile:711)
at android.support.v4.content.FileProvider.getUriForFile(SourceFile:400)
这是清单中我的文件提供者的定义:
Here is the definition of my file provider in my manifest:
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_provider_paths" />
</provider>
具有配置路径的资源文件:
The resource file with configured paths:
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-files-path name="external_files" path="" />
</paths>
关于此问题的起因的任何想法，以及为什么仅在华为设备上发生?如果我没有华为设备，该如何调试?
Any idea on the cause of this issue and why it happens only on Huawei devices? How would I debug this, given that I don't have a Huawei device?
更新:
我在应用程序中添加了更多日志，在这些设备上同时打印ContextCompat.getExternalFilesDirs和context.getExternalFilesDir时，结果不一致:
I've added more logs into my app and I got some inconsistent results when printing both ContextCompat.getExternalFilesDirs and context.getExternalFilesDir on these devices:
ContextCompat.getExternalFilesDirs:
/storage/emulated/0/Android/data/<package>/files
/storage/sdcard1/Android/data/<package>/files
context.getExternalFilesDir:
/storage/sdcard1/Android/data/<package>/files
这与ContextCompat.getExternalFilesDirs的文档不一致，该文档指出The first path returned is the same as getExternalFilesDir(String)
This is inconsistent with the documentation of ContextCompat.getExternalFilesDirs that states that The first path returned is the same as getExternalFilesDir(String)
这解释了这个问题，因为我在代码中使用了context.getExternalFilesDir而FileProvider使用了ContextCompat.getExternalFilesDirs.
That explains the issue since I use context.getExternalFilesDir in my code and FileProvider uses ContextCompat.getExternalFilesDirs.
推荐答案
Android N的更新(下面保留了原始答案，并确认了这种新方法可以在生产环境中使用):
正如您在更新中指出的那样，许多华为设备型号(例如KIW-L24，ALE-L21，ALE-L02，PLK-L01和其他各种设备)都违反了Android呼叫ContextCompat#getExternalFilesDirs(String)的合同.如果存在数组，它们将返回第一个对象作为到外部SD卡的路径，而不是将Context#getExternalFilesDir(String)(即默认条目)作为数组中的第一个对象返回.
As you noted in your update, many Huawei device models (e.g. KIW-L24, ALE-L21, ALE-L02, PLK-L01, and a variety of others) break the Android contract for calls to ContextCompat#getExternalFilesDirs(String).
Rather than returning Context#getExternalFilesDir(String) (ie the default entry) as the first object in the
array, they instead return the first object as the path to the external SD card, if one is present.
通过违反此订购合同，这些带有外部SD卡的华为设备将在呼叫FileProvider#getUriForFile(Context, String, File)的external-files-path根目录时以IllegalArgumentException崩溃.您可以尝试使用多种解决方案来尝试解决此问题(例如，编写自定义FileProvider实现)，但我发现最简单的方法是捕获此问题，并:
By breaking this ordering contract, these Huawei devices with external SD cards will crash with an IllegalArgumentException on calls to FileProvider#getUriForFile(Context, String, File) for external-files-path roots. While there are a variety of solutions that you can pursue to attempt to deal with this issue (e.g. writing a custom FileProvider implementation), I've found the easiest approach is to catch this issue and:
- Pre-N:返回
Uri#fromFile(File)，由于FileUriExposedException，它不适用于Android N及更高版本
- N:将文件复制到您的
cache-path(注意:如果在UI线程上执行此操作，可能会引入ANR)，然后为复制的文件返回FileProvider#getUriForFile(Context, String, File)(即，完全避免了该错误)
- Pre-N: Return
Uri#fromFile(File), which won't work with Android N and above due toFileUriExposedException - N: Copy the file to your
cache-path(note: this can introduce ANRs if done on the UI Thread) and then returnFileProvider#getUriForFile(Context, String, File)for the copied file (ie avoiding the bug altogether)
完成此操作的代码如下:
Code to accomplish this can be found below:
public class ContentUriProvider {
private static final String HUAWEI_MANUFACTURER = "Huawei";
public static Uri getUriForFile(@NonNull Context context, @NonNull String authority, @NonNull File file) {
if (HUAWEI_MANUFACTURER.equalsIgnoreCase(Build.MANUFACTURER)) {
Log.w(ContentUriProvider.class.getSimpleName(), "Using a Huawei device Increased likelihood of failure...");
try {
return FileProvider.getUriForFile(context, authority, file);
} catch (IllegalArgumentException e) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
Log.w(ContentUriProvider.class.getSimpleName(), "Returning Uri.fromFile to avoid Huawei 'external-files-path' bug for pre-N devices", e);
return Uri.fromFile(file);
} else {
Log.w(ContentUriProvider.class.getSimpleName(), "ANR Risk -- Copying the file the location cache to avoid Huawei 'external-files-path' bug for N+ devices", e);
// Note: Periodically clear this cache
final File cacheFolder = new File(context.getCacheDir(), HUAWEI_MANUFACTURER);
final File cacheLocation = new File(cacheFolder, file.getName());
InputStream in = null;
OutputStream out = null;
try {
in = new FileInputStream(file);
out = new FileOutputStream(cacheLocation); // appending output stream
IOUtils.copy(in, out);
Log.i(ContentUriProvider.class.getSimpleName(), "Completed Android N+ Huawei file copy. Attempting to return the cached file");
return FileProvider.getUriForFile(context, authority, cacheLocation);
} catch (IOException e1) {
Log.e(ContentUriProvider.class.getSimpleName(), "Failed to copy the Huawei file. Re-throwing exception", e1);
throw new IllegalArgumentException("Huawei devices are unsupported for Android N", e1);
} finally {
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);
}
}
}
} else {
return FileProvider.getUriForFile(context, authority, file);
}
}
}
与file_provider_paths.xml一起:
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-files-path name="public-files-path" path="." />
<cache-path name="private-cache-path" path="." />
</paths>
创建了这样的类后，将您的调用替换为:
Once you've created a class like this, replace your calls to:
FileProvider.getUriForFile(Context, String, File)
具有:
ContentUriProvider.getUriForFile(Context, String, File)
坦率地说，我认为这不是一个特别优雅的解决方案，但是它确实允许我们使用正式记录的Android行为，而无需做任何过于激烈的事情(例如，编写自定义的FileProvider实现).我已经在生产环境中进行了测试，因此可以确认它可以解决这些华为故障.对我来说，这是最好的方法，因为我不想花太多时间解决明显是制造商的缺陷.
Frankly, I don't think this is an especially graceful solution, but it does allow us to use formally documented Android behavior without doing anything too drastic (e.g. writing a custom FileProvider implementation). I have tested this in production, so I can confirm that it resolves these Huawei crashes. For me, this was the best approach, since I didn't wish to spend too much time addressing what is quite obviously a manufacturer's defect.
从此问题之前的华为设备更新到Android N:
由于FileUriExposedException，这不适用于Android N及更高版本，但是我还没有遇到华为设备在Android N上的这种错误配置.
This won't work with Android N and above due to FileUriExposedException, but I have yet to encounter a Huawei device with this mis-configuration on Android N.
public class ContentUriProvider {
private static final String HUAWEI_MANUFACTURER = "Huawei";
public static Uri getUriForFile(@NonNull Context context, @NonNull String authority, @NonNull File file) {
if (HUAWEI_MANUFACTURER.equalsIgnoreCase(Build.MANUFACTURER) && Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
Log.w(ContentUriProvider.class.getSimpleName(), "Using a Huawei device on pre-N. Increased likelihood of failure...");
try {
return FileProvider.getUriForFile(context, authority, file);
} catch (IllegalArgumentException e) {
Log.w(ContentUriProvider.class.getSimpleName(), "Returning Uri.fromFile to avoid Huawei 'external-files-path' bug", e);
return Uri.fromFile(file);
}
} else {
return FileProvider.getUriForFile(context, authority, file);
}
}
}
这篇关于华为设备上的FileProvider错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
