Question

我正在尝试从“偏好设置”活动将我的应用数据库备份/恢复到外部sdCard。我能够将数据库保存到外部sdCard，但现在我不明白如何将此文件传输回其默认路径（data \ package.app \ databases）。有什么想法吗？

Answer 1

我这样做：

出口：

InputStream myInput;
            String dbpath = "/data/"+pckgname+"/databases/refuel_db";
            String sdpath = Environment.getExternalStorageDirectory().getPath();

            try {

                myInput = new FileInputStream(Environment.getDataDirectory()
                        + dbpath);


                // Set the output folder on the Scard
                File directory = new File(sdpath + "/Refuel");
                // Create the folder if it doesn't exist:
                if (!directory.exists()) {
                    directory.mkdirs();
                }
                // Set the output file stream up:

                OutputStream myOutput = new FileOutputStream(directory.getPath()
                        + "/refuel_db");

                // Transfer bytes from the input file to the output file
                byte[] buffer = new byte[1024];
                int length;
                while ((length = myInput.read(buffer)) > 0) {
                    myOutput.write(buffer, 0, length);
                }
                // Close and clear the streams

                myOutput.flush();

                myOutput.close();

                myInput.close();

                Toast.makeText(getActivity(), "Backup Done Succesfully!", Toast.LENGTH_LONG)
                        .show();

            } catch (FileNotFoundException e) {
                Toast.makeText(getActivity(), "ERROR " + e, Toast.LENGTH_LONG).show();

                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                Toast.makeText(getActivity(), "ERROR " + e, Toast.LENGTH_LONG).show();

                // TODO Auto-generated catch block
                e.printStackTrace();
            }

导入：

 OutputStream myOutput;

            String dbpath = "/data/"+pckgname+"/databases/refuel_db";
            String sdpath = Environment.getExternalStorageDirectory().getPath();

            try {

                myOutput = new FileOutputStream(Environment.getDataDirectory()
                        + dbpath);

                // Set the folder on the SDcard
                File directory = new File(sdpath + "/Refuel");
                // Set the input file stream up:

                InputStream myInputs = new FileInputStream(directory.getPath()
                        + "/refuel_db");

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

                // Close and clear the streams
                myOutput.flush();

                myOutput.close();

                myInputs.close();

                Toast.makeText(getActivity(), "Import Done Succesfully!", Toast.LENGTH_LONG)
                        .show();

            } catch (FileNotFoundException e) {
                Toast.makeText(getActivity(), "ERROR " + e, Toast.LENGTH_LONG).show();

                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                Toast.makeText(getActivity(), "ERROR " + e, Toast.LENGTH_LONG).show();

                // TODO Auto-generated catch block
                e.printStackTrace();
            }

在Android中备份/还原到SD卡

1 个答案: