使用Android 4.4复制数据库

Question

I have a Problem when I want to copy a database from the assets to the device. I always get a FileNotFoundException. Also terminate and relaunch don't work. In the Debugger the content of the variables seems to be ok.

My code:

private void copyDatabase() throws IOException {
    if (DEBUG) Log.d(TAG, "copyDatabase");
    String DB_PATH = myContext.getDatabasePath(DATABASE_NAME).toString();

    AssetManager assetManager = myContext.getResources().getAssets();
    InputStream inputStream = null;

    try {
        inputStream = assetManager.open(DATABASE_NAME);
    } catch (IOException ex) {
        Log.d(TAG, "InputStream Exception");
    }

    if (inputStream != null) {
        OutputStream outputStream = new FileOutputStream(DB_PATH);

        byte[] buffer = new byte[1024];
        int length;

        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }

        outputStream.flush();
        outputStream.close();
        inputStream.close();
    }
}

The Line OutputStream outputStream = new FileOutputStream(DB_PATH); raises the exception.

DB_PATH: /data/data/com.wiget.autokatalog/databases/autokatalog.db3 cause ErrnoException (id=830031910480) detailMessage "/data/data/com.wiget.autokatalog/databases/autokatalog.db3: open failed: ENOENT (No such file or directory)" (id=830031912168)

I thought that the File will be created with this line.

Could there be a permission Problem (eg something missing in the AndroidManifest) ?

Thanks for you help.

/Andre

Answer 1

/data/data/com.wiget.autokatalog/databases/ maybe not exists if you have not created any database before this. Try the following:

    public File copyFromAssetsTo(String fromFile, String toPath) {
    AssetManager assetManager = context.getAssets();

    try {
        String[] arr = toPath.split("/");
        String fileName = arr[arr.length - 1];
        String fileDirPath = toPath.replaceAll(fileName, "");
        File fileDir = new File(fileDirPath);

        if(!fileDir.exists()) {
            fileDir.mkdirs();
        }

        File file = new File(fileDir, fileName);
        InputStream in = assetManager.open(fromFile);
        OutputStream out = new FileOutputStream(file);
        copyFile(in, out);
        out.close();
        return file;
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}