拍照时获取 - java.lang.Throwable: file:// Uri 通过 ClipData.Item.getUri() 暴露

Question

例外是：

file:// Uri exposed through ClipData.Item.getUri()
java.lang.Throwable: file:// Uri exposed through ClipData.Item.getUri()
    at android.os.StrictMode.onFileUriExposed(StrictMode.java:1618)
    at android.net.Uri.checkFileUriExposed(Uri.java:2341)
    at android.content.ClipData.prepareToLeaveProcess(ClipData.java:808)
    at android.content.Intent.prepareToLeaveProcess(Intent.java:7926)
    at android.app.Instrumentation.execStartActivity(Instrumentation.java:1506)
    at android.app.Activity.startActivityForResult(Activity.java:3832)
    at android.app.Activity.startActivityForResult(Activity.java:3783)
    at android.support.v4.app.FragmentActivity.startActivityFromFragment(Unknown Source)
    at android.support.v4.app.Fragment.startActivityForResult(Unknown Source)
    at me.chunyu.ChunyuDoctor.Utility.w.takePhoto(Unknown Source)
    at me.chunyu.ChunyuDoctor.Dialog.ChoosePhotoDialogFragment.takePhoto(Unknown Source)
    at me.chunyu.ChunyuDoctor.Dialog.ChoosePhotoDialogFragment.access$000(Unknown Source)
    at me.chunyu.ChunyuDoctor.Dialog.b.onClick(Unknown Source)
    at me.chunyu.ChunyuDoctor.Dialog.ChoiceDialogFragment.onClick(Unknown Source)
    at android.view.View.performClick(View.java:4848)
    at android.view.View$PerformClick.run(View.java:20270)
    at android.os.Handler.handleCallback(Handler.java:815)
    at android.os.Handler.dispatchMessage(Handler.java:104)
    at android.os.Looper.loop(Looper.java:194)
    at android.app.ActivityThread.main(ActivityThread.java:5643)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

我的代码在这里：

public static void takePhoto(Fragment fragment, int token, Uri uri) {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (uri != null) {
        intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
    }
    fragment.startActivityForResult(intent, token);
}

我搜索了类似的问题和解决方案。 并修改代码如下：

public static void takePhoto(Fragment fragment, int token, Uri uri) {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
            | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
    if (uri != null) {
        intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
        intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
    }
    fragment.startActivityForResult(intent, token);
}

但这也行不通。

它发生在 Android 5.1 上，而在 Android 4.3 上运行良好。 有没有人遇到同样的问题？ 要求一些预付款。 在线等待...

Answer 1

我已经解决了这个问题。

首先，出现此问题是因为 StrictMode 阻止使用 file:// 方案传递 URI。

所以有两种解决方案：

1. 更改StrictMode。请参阅 similar problem 和 its code。 但是对于我们的应用来说，修改Android源代码是不现实的。

2. 使用另一个 URI 方案，而不是 file://。例如，content:// 与 MediaStore 相关。

所以我选择了第二种方法：

private void doTakePhoto() {
    try {
        ContentValues values = new ContentValues(1);
        values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpg");
        mCameraTempUri = getActivity().getContentResolver()
                .insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

        takePhoto(this, RequestCode.REQCODE_TAKE_PHOTO, mCameraTempUri);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void takePhoto(Fragment fragment, int token, Uri uri) {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
        | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
    if (uri != null) {
        intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
        intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
    }
    fragment.startActivityForResult(intent, token);
}

另外，还有一个solution。

Answer 2

所以，我实际上是在阅读这方面的内容，似乎处理此问题的正确解决方案如下：

String mCurrentPhotoPath;

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
        imageFileName,  /* prefix */
        ".jpg",         /* suffix */
        storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = "file:" + image.getAbsolutePath();
    return image;
}

static final int REQUEST_TAKE_PHOTO = 1;

private void dispatchTakePictureIntent() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            // Error occurred while creating the File
            ...
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                                                  "com.example.android.fileprovider",
                                                  photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }
}

请注意，Google 说要创建一个“content://”文件，而不是基于“file://”的资源。

这是来自谷歌：

Note: We are using getUriForFile(Context, String, File) which returns a content:// URI. For more recent apps targeting Android N 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.

此外，您还需要设置以下内容： Now, you need to configure the FileProvider. In your app's manifest, add a provider to your application:

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

注意：（取自谷歌网站）Make sure that the authorities string matches the second argument to getUriForFile(Context, String, File). In the meta-data section of the provider definition, you can see that the provider expects eligible paths to be configured in a dedicated resource file, res/xml/file_paths.xml. Here is the content required for this particular example:

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

如果您想了解更多信息：请在此处阅读 https://developer.android.com/training/camera/photobasics.html

Answer 3

除了使用 FileProvider 的解决方案之外，还有另一种解决方法。简单地放在 Application.onCreate() 方法中。这样VM就忽略了文件URI暴露。

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

Answer 4

这个错误的原因是 file:// uri 方案不再支持，因为安全性暴露。 https://code.google.com/p/android/issues/detail?id=203555

在使用 targetSDK 'N' 之后，我们不能再使用 file:// uri。 https://commonsware.com/blog/2016/03/14/psa-file-scheme-ban-n-developer-preview.html

所以，答案是正确的。任何使用 file:// 的人都可以更改 content:// 以提供各种本地文件。

Answer 5

总结一下： file:// 方案现在不允许在 targetSdkVersion 24 (Android Nougat) 上附加 Intent

如果您计划支持 api 24+，则必须更改您的代码 两个链接： https://developer.android.com/training/camera/photobasics.html https://inthecheesefactory.com/blog/how-to-share-access-to-file-with-fileprovider-on-android-nougat/en