Android（写入外部 SD 卡）：java.io.IOException：权限被拒绝

Question

当我想在我的外部 SD 卡（名为 /storage/B9BE-18A6）上创建文件时，出现 "Permission denied" 错误。

我知道你必须以编程方式请求写入权限，因为 Android M。所以我插入了 Arpit Patel (Android 6.0 Marshmallow. Cannot write to SD Card)

的解决方案

我不知道为什么我仍然没有这样做的权限。你们有其他解决方案可以让我在 SD 卡上创建文件吗？

创建文件的代码

    FloatingActionButton fab_new_file = (FloatingActionButton) rLayoutFrgEmpresas.findViewById(R.id.fab_menu_item_file);
    fab_new_file.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {

            int permission = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE);
            if (permission != PackageManager.PERMISSION_GRANTED) {
                Log.v("Permission: " ,"Denied");

                if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),
                        Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
                    builder.setMessage("Permission to access the SD-CARD is required")
                            .setTitle("Permission required");

                    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                        public void onClick(DialogInterface dialog, int id) {
                            Log.i(TAG, "Clicked");
                            makeRequest();
                        }
                    });

                    AlertDialog dialog = builder.create();
                    dialog.show();

                } else {
                    makeRequest();
                }
            }else{
                Log.v("Permission: " ,"Granted");
                File file = new File(textView_currentPath.getText() + "/" + "testfile.txt");
                Log.v("filepatch: ", ""+file);
                if (!file.exists()) {
                    Log.v("Does "+file+" exists?", "No");
                    try {
                        file.createNewFile();
                        getFilesFromDir(textView_currentPath.getText() + "", textView_currentPath.getText() + "");
                        Log.v("File "+file,"has been created!");
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    });

LogCat

04-11 16:31:40.709 23404-23404/spicysoftware.com.phonemanager D/ViewRootImpl@ab22b33[MainActivity]: ViewPostImeInputStage processPointer 0
04-11 16:31:40.773 23404-23404/spicysoftware.com.phonemanager D/ViewRootImpl@ab22b33[MainActivity]: ViewPostImeInputStage processPointer 1
04-11 16:31:40.783 23404-23404/spicysoftware.com.phonemanager V/Permission:: Granted
04-11 16:31:40.783 23404-23404/spicysoftware.com.phonemanager V/filepatch:: /storage/B9BE-18A6/testfile.txt
04-11 16:31:40.783 23404-23404/spicysoftware.com.phonemanager V/Does /storage/B9BE-18A6/testfile.txt exists?: No
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err: java.io.IOException: Permission denied
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at java.io.UnixFileSystem.createFileExclusively0(Native Method)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at java.io.UnixFileSystem.createFileExclusively(UnixFileSystem.java:280)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at java.io.File.createNewFile(File.java:948)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at spicysoftware.com.phonemanager.StorageFragment.onClick(StorageFragment.java:187)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.view.View.performClick(View.java:6207)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.view.View$PerformClick.run(View.java:23639)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.os.Handler.handleCallback(Handler.java:751)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.os.Looper.loop(Looper.java:154)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6688)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
04-11 16:31:40.784 23404-23404/spicysoftware.com.phonemanager W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)

解决方法 感谢@greenapps 让我走上了正确的道路。解决方案在 https://developer.android.com/guide/topics/providers/document-provider.html

中有很好的记录

        Intent intent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);

        String mimeType = "text/plain";
        String filename = "file"+System.currentTimeMillis() + ".txt";
        intent.setType(mimeType);
        intent.putExtra(Intent.EXTRA_TITLE, filename);
        startActivityForResult(intent, CREATE_REQUEST_CODE);

Answer 1

SD卡是只读的。所以你不能写。您只能写入 SD 卡上的应用特定目录。在你的情况下它将是

/storage/B9BE-18A6/Android/data/spicysoftware.com.phonemanager

如果你想写在整个SD卡上那么文件class和FileOutputStream是不行的。那么你必须使用存储访问框架。

Android（写入外部 SD 卡）：java.io.IOException：权限被拒绝

Android (Write on external SD-Card): java.io.IOException: Permission denied

android

ioexception

permission-denied

android-sdcard

android-6.0-marshmallow