相关疑难解决方法(0)

我正进入(状态

开放失败: EACCES (Permission denied)

在线上 OutputStream myOutput = new FileOutputStream(outFileName);

我检查了根,我试过了android.permission.WRITE_EXTERNAL_STORAGE.

我该如何解决这个问题？

try {
    InputStream myInput;

    myInput = getAssets().open("XXX.db");

    // Path to the just created empty db
    String outFileName = "/data/data/XX/databases/"
            + "XXX.db";

    // Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    // Transfer bytes from the inputfile to the outputfile
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer)) > 0) {
        myOutput.write(buffer, 0, length);
    }

    // Close the …

我已经加入uses-permission包括WRITE_EXTERNAL_STORAGE,MOUNT_UNMOUNT_FILESYSTEMS,READ_EXTERNAL_STORAGE来AndroidManifest.xml.

当我尝试在Nexus5(Android 6.0)中运行我的应用程序时,它抛出了一个异常,如下所示:

java.io.IOException: open failed: EACCES (Permission denied)

我尝试了另一款Android手机(Android 5.1),一切都很好.这是代码:

private File createImageFile() throws IOException {
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(imageFileName, ".jpg", storageDir);
    currentPhotoPath = image.getAbsolutePath();
    return image;
}

Android 6.0在许可方面有区别吗？

我在某些设备上访问存储时遇到了一个非常奇怪的问题.该应用程序适用于我的测试设备(Nexus 4和7,三星GS5).我的所有设备都运行Android 4.4.2.但是我收到了很多用户的电子邮件,说应用程序无法写入存储(内部存储和SD卡).从用户反馈收到的日志文件中,我可以看到问题是以下代码:

try {
    if (fStream == null) {
    fStream = new FileOutputStream(filename, true);
}
    fStream.write(data, 0, bytes);
    return;
} catch (IOException ex) {
    ex.printStackTrace();
}

它在fStream = new FileOutputStream(filename,true)行抛出异常; 在创建FileOutputStream时.

堆栈日志是:

W/System.err( 8147): Caused by: java.io.FileNotFoundException: /storage/emulated/0/my_folder/test_file_name.png: open failed: EACCES (Permission denied)
w/System.err( 8147):    at libcore.io.IoBridge.open(IoBridge.java:409)
W/System.err( 8147):    at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
W/System.err( 8147):    at java.io.FileOutputStream.<init>(FileOutputStream.java:128)
W/System.err( 8147):    at myapp.save(SourceFile:515)
W/System.err( 8147):    ... 8 more
W/System.err( 8147): Caused by: libcore.io.ErrnoException: open failed: EACCES (Permission denied)
W/System.err( 8147):    at libcore.io.Posix.open(Native Method) …

关于如何在SD卡(android 5及以上版本)中编写(和重命名)文件的大量调查结果后,我认为android提供的新SAF需要获得用户写入SD卡文件的许可.

我在这个文件管理器应用程序ES文件资源管理器中看到,最初它采用以下方式读取和写入权限,如图片所示.

选择SD卡后,授予写入权限.

因此我尝试使用SAF的方式相同,但重命名文件失败了.我的代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    rename = (Button) findViewById(R.id.rename);

    startActivityForResult(new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE), 42);
}

@Override
public void onActivityResult(int requestCode,int resultCode,Intent resultData) {
    if (resultCode != RESULT_OK)
        return;
    Uri treeUri = resultData.getData();
    DocumentFile pickedDir = DocumentFile.fromTreeUri(this, treeUri);
    grantUriPermission(getPackageName(), treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
    getContentResolver().takePersistableUriPermission(treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
}

public void renameclick(View v) {
    File ff = new File("/storage/sdcard1/try1.jpg");
    try {
        ff.createNewFile();
    } catch (Exception e) {
        Log.d("error", "creating");
        e.printStackTrace();
    }
} …