android - 写入SD卡总是失败

Question

我正在尝试从任何位置(包括内部设备存储)移动文件到 SD 卡，

我有

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

在我的 list 中，并通过检查是否授予权限来检查它是否有效:

Contex.checkCallingOrSelfPermission("android.permission.WRITE_EXTERNAL_STORAGE") 和 Contex.checkCallingOrSelfPermission("android.permission.READ_EXTERNAL_STORAGE")

我已经尝试了 3 种不同的方法来做到这一点:

1. Files.move(original, newPath1)，Guava com.google.common.io自带

2. 这个方法:

   public static void move(File src, File dst) throws IOException {
       FileInputStream inStream = new FileInputStream(src);
       FileOutputStream outStream = new FileOutputStream(dst);
       FileChannel inChannel = inStream.getChannel();
       FileChannel outChannel = outStream.getChannel();
       inChannel.transferTo(0, inChannel.size(), outChannel);
       inStream.close();
       outStream.close();
   }
   

3. original.renameTo(newPath1);

我阅读了很多关于此的 SO 帖子，但我尝试的所有解决方案均无效，我确保已安装 SD 卡，并且在尝试时我没有将我的设备连接到 PC。我什至用 SD 卡尝试了 2 种不同的设备。请注意，我可以使用具有完全相同路径的 BitmapFactory.decode() 访问图像，并且可以将该图像加载到 imageview。

我总是收到 EACCES(权限被拒绝)。我不知道还能做些什么来解决这个问题:(

11-13 11:11:54.358 19192-19372/xaday.ofek.ron.xaday W/System.err: java.io.FileNotFoundException: /storage/sdcard1/DCIM/thai2/IMG-20150702-WA0001.jpg: open failed: EACCES (Permission denied)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:465)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:87)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at com.google.common.io.Files$FileByteSink.openStream(Files.java:245)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at com.google.common.io.Files$FileByteSink.openStream(Files.java:233)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at com.google.common.io.ByteSource.copyTo(ByteSource.java:248)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at com.google.common.io.Files.copy(Files.java:458)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at com.google.common.io.Files.move(Files.java:673)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at xaday.ofek.ron.xaday.XaDayIntentService.handleActionMove(XaDayIntentService.java:128)
11-13 11:11:54.369 19192-19372/xaday.ofek.ron.xaday W/System.err:     at xaday.ofek.ron.xaday.XaDayIntentService.onHandleIntent(XaDayIntentService.java:84)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.Looper.loop(Looper.java:211)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.HandlerThread.run(HandlerThread.java:61)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.Posix.open(Native Method)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:451)
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err:   ... 12 more
11-13 11:11:54.370 19192-19372/xaday.ofek.ron.xaday W/System.err: java.io.FileNotFoundException: /storage/sdcard1/DCIM/thai2/IMG-20150702-WA0001.jpg: open failed: EACCES (Permission denied)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:465)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:87)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:72)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at xaday.ofek.ron.xaday.FileUtils.move(FileUtils.java:36)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at xaday.ofek.ron.xaday.XaDayIntentService.handleActionMove(XaDayIntentService.java:136)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at xaday.ofek.ron.xaday.XaDayIntentService.onHandleIntent(XaDayIntentService.java:84)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.Looper.loop(Looper.java:211)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at android.os.HandlerThread.run(HandlerThread.java:61)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.Posix.open(Native Method)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:451)
11-13 11:11:54.371 19192-19372/xaday.ofek.ron.xaday W/System.err:   ... 9 more

为了确保我没有以某种方式锁定文件，我使用了另一个文件管理器应用程序来执行相同的文件移动 - 并且成功了!为什么它对我不起作用？!

有人有想法吗？

Answer 1

在 Android Kitkat (4.4) 上，Google 更改了开发人员访问可移动存储(SD 卡)的方式。引自 source.android.com :

The WRITE_EXTERNAL_STORAGE permission must only grant write access to the primary external storage on a device. Apps must not be allowed to write to secondary external storage devices, except in their package-specific directories as allowed by synthesized permissions. Restricting writes in this way ensures the system can clean up files when applications are uninstalled.

因此，即使有 WRITE_EXTERNAL_STORAGE 权限，您也不能在 KitKat 及更高版本上写入 SD 卡。

在 Android Lollipop (5.0) 上，Google 添加了一组新的 API，允许开发人员通过 Storage Access Framework 管理 SD 卡上的文件。 .

这个 StackOverflow 回答详细解释了如何使用新的 API 和现有的限制:

How to use the new SD card access API presented for Android 5.0 (Lollipop)?