Android7.0拍照失败FileUriExposedException,你的拍照代码升级了吗

时间：2022-06-18 18:28:37

背景:

SamSung SM-N9006 Android5.0在应用中拍照之后，无法获取拍照之后的数据，报错FileUriExposedException

思路：

参考官方文档对该错误的解释，是由于出于安全考虑，Android 7.0[API24]以及以上版本不支持file://，使用content://URI，可能三星这款机型动了Framework吧。

Note: We are using getUriForFile(Context, String, File) which returns a content:// URI. For more recent apps targeting Android 7.0 (API level 24) and higher, passing a file:// URI across a package boundary causes a FileUriExposedException. Therefore, we now present a more generic way of storing images using a FileProvider.

关键方法:

1.启动照相时，借助FileProvider生成content://URI保存拍照结果

   /**
 * 老方法[Android7.0以及以上报错FileUriExposedException]
 */
private void doTakePhotoOld() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (intent.resolveActivity(getPackageManager()) != null) {
            File newFile = createTakePhotoFile();
            intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(newFile));
            startActivityForResult(intent, REQUEST_CAMERA);
        }
    }
/**
 * 拍照新方法[全尺寸]
 */
private void doTakePhoto() {
        Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePhotoIntent.resolveActivity(getPackageManager()) != null) {
            File newFile = createTakePhotoFile();
            Uri contentUri = FileProvider.getUriForFile(this, "com.harry.shopping.fileprovider", newFile);
            Log.i(TAG, "contentUri = " + contentUri.toString());
                        List<ResolveInfo> resInfoList= getPackageManager().queryIntentActivities(takePhotoIntent, PackageManager.MATCH_DEFAULT_ONLY);
for (ResolveInfo resolveInfo : resInfoList) {
                String packageName = resolveInfo.activityInfo.packageName;
                grantUriPermission(packageName, contentUri,
                        Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
            }
            takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, contentUri);
            startActivityForResult(takePhotoIntent, REQUEST_CAMERA);
        }
    }
/**
 * @return 拍照之后存储的文件
 */
@NonNull
private File createTakePhotoFile() {
        File imagePath = new File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "take_photo");
if (!imagePath.exists()) {
            imagePath.mkdirs();
        }
        File file = new File(imagePath, "default_image.jpg");
        mCurrentPhotoPath = file.getPath();// 存储拍照的路径
return file;
    }

小米复现java.lang.SecurityException: Permission Denial: opening provider android.support.v4.content.FileProvider from ProcessRecord{42725078 24872:com.android.camera/u0a14} (pid=24872, uid=10014) that is not exported from uid 10310，此时需要for循环授权进行修复。

2.对FileProvider进行设置

2.1AndroidManifest.xml注册

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

注意，android:authorities属性值和之前FileProvider.getUriForFile方法使用的authorities必须保持一致。

2.2在res/xml新建file_paths.xml设置文件路径

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="images" path="Android/data/com.harry.shopping/files/Pictures" />
</paths>

经过以上操作就可以在onActivityResult里面获取到照片路径mCurrentPhotoPath。

附录1：使用时FileProvider五个步骤

1.定义一个FileProvider，并在AndroidManifest.xml注册。一般v4包下的的FileProvider即可

<provider
 android:name="android.support.v4.content.FileProvider"
android:authorities="com.harry.shopping.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
 android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>

2.Provider配置文件路径
2.1配置meta-data指定保存文件路径

<meta-data
    android:name="android.support.FILE_PROVIDER_PATHS"
    android:resource="@xml/file_paths"/>

2.2在xml文件下新建file_paths配置路径

<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="my_images" path="Android/data/com.harry.shopping/files/Pictures" />
</paths>

name表示生成URI时的别名，path是指相对路径

<files-path name="name" path="path" />
Context.getFilesDir()
<cache-path name="name" path="path" />
Context.getCacheDir()
<external-path name="name" path="path" />
Environment.getExternalStorageDirectory()
<external-files-path name="name" path="path" />
Context#getExternalFilesDir(String) Context.getExternalFilesDir(null).
<external-cache-path name="name" path="path" />
Context.getExternalCacheDir()

3.为一个文件生成Content URI

File imagePath = new File(Context.getFilesDir(), "images");
File newFile = new File(imagePath, "default_image.jpg");
Uri contentUri = getUriForFile(getContext(), "com.mydomain.fileprovider", newFile);

生成URI：content://com.mydomain.fileprovider/my_images/default_image.jpg
4.为URI临时授权,两种方法

1)Context.grantUriPermission(package, Uri, mode_flags);// mode_flags可以设置为 FLAG_GRANT_READ_URI_PERMISSION, FLAG_GRANT_WRITE_URI_PERMISSION

权限失效：用户取消权限[revokeUriPermission() ]或者手机重启

2)Intent intent = new Intent();
intent.setData(Uri);
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION|Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
setResult(RESULT_OK,intent);

权限失效：返回处理结果Activity所在的stack结束

5.发送这个URI给其他APP，两种方法
1)startActivityResult()
2)借助ClipData处理

附录2：最近路径容易搞混，也打印记录下

        Context.getFilesDir()=/data/data/com.harry.shopping/files
        Context.getCacheDir()=/data/data/com.harry.shopping/cache
        Environment.getExternalStorageDirectory()=/storage/emulated/0
        getExternalFilesDir(Environment.DIRECTORY_PICTURES)=/storage/emulated/0/Android/data/com.harry.shopping/files/Pictures
        Context.getExternalFilesDir(null)=/storage/emulated/0/Android/data/com.harry.shopping/files
        Context.getExternalCacheDir()=/storage/emulated/0/Android/data/com.harry.shopping/cache

总结

这类问题比较简单，查看报错Log，参考官方文档，借助FileProvider可以方便的处理这类安全问题。

参考文献：

https://developer.android.com/training/camera/photobasics.html
https://developer.android.com/reference/android/support/v4/content/FileProvider.html
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