如何管理 Android 11 中的文件和文件夹保持向后兼容性

Question

I need to make my application compatible with android versions greater than 29 (Android 11+). Currently I create a folder tree with the following code:

   public void createFolder() {
        try {
            ArrayList<File> listDir = new ArrayList<>();
            listDir.add(new File(MAIN_FOLDER));
            listDir.add(new File(CONFIG_FOLDER_ROOT));
            listDir.add(new File(PDF_FOLDER));
            listDir.add(new File(THUMB_FOLDER));
            listDir.add(new File(LOGS_FOLDER));
            listDir.add(new File(ARCHIVE_FOLDER));
            listDir.add(new File(ZOMBIE_FOLDER));
            listDir.add(new File(DATASHEET_FOLDER));

            for (int i = 0; i < listDir.size(); i++) {
                if (!listDir.get(i).exists()) {
                    if (listDir.get(i).mkdirs()) {
                        //Creo il file .incarichi
                        if (listDir.get(i).getName().compareToIgnoreCase(".Data") == 0) {
                            File fileIncarichi = new File(listDir.get(i).getAbsolutePath(), ASSIGNMENT_FILE);
                            if (!fileIncarichi.exists()) {
                                fileIncarichi.createNewFile();
                            }
                        }

                        //Creo il file .warning
                        if (listDir.get(i).getName().compareToIgnoreCase(".Logs") == 0) {
                            File fileIncarichi = new File(listDir.get(i).getAbsolutePath(), WARNING_FILE);
                            if (!fileIncarichi.exists()) {
                                fileIncarichi.createNewFile();
                            }
                            File fileConfig = new File(listDir.get(i).getAbsolutePath(), CONFIG_FILE);
                            if (!fileConfig.exists()) {
                                fileConfig.createNewFile();
                            }
                        }

                        //Creo i file .nomedia
                        File fileMedia = new File(listDir.get(i).getAbsolutePath(), ".nomedia");
                        if (!fileMedia.exists()) {
                            fileMedia.createNewFile();
                        }
                    }
                }
            }
        } catch (Exception e) {
            wil.WriteFile("1)FilesUtilities - Exception: " + e.getMessage());
        }
    }

These are examples of the variables I pass to the "newFile()" functions:

public final static String MAIN_FOLDER = Environment.getExternalStorageDirectory() + "/.MYAPP";
public final static String THUMB_FOLDER = Environment.getExternalStorageDirectory() + "/.MYAPP/.Thumbs";

To maintain compatibility with new android versions I have inserted in the manifest and right now everything is working fine:

android:requestLegacyExternalStorage="true"

I received a notice via the play store that by May 5 I have to adapt my app so that it is compliant to the new policies, so I started to read up on how to make the app compatible with all versions of android, but I have some doubts on how to proceed.

Keeping in mind that I cannot create "custom" folders, could it be enough to create my directories directly in a public folder such as "Download, Documents" or is it necessary to completely change the procedures for creating and accessing files using "media store" or the "store access framework"?

Answer 1

Write your files in the classic way to a subdirectory of the public Documents folder.

They will survive.

But not reachable by classic file means (unless your app has 'all files access') but with SAF.