Android Java导入sqlite数据库时没有这样的文件或目录

Question

我正在尝试导入一个sqlite数据库，以使其覆盖当前的数据库。我已经设法将数据库导出到电话上的文件夹中的文件中，但是当我尝试导入数据库时​​，出现了异常提示“没有这样的文件或目录”。我该如何解决？

这是我的数据库导出到文件的代码

private void exportDB() {
    try {
        File sd = Environment.getExternalStorageDirectory();
        File data = Environment.getDataDirectory();

        if (sd.canWrite()) {
            String  currentDBPath= "//data//" + "com.varcon.campus"
                    + "//databases//" + "CampusTime.db";
            String backupDBPath  = "/Download/CampusTime";
            File currentDB = new File(data, currentDBPath);
            File backupDB = new File(sd, backupDBPath);

            FileChannel src = new FileInputStream(currentDB).getChannel();
            FileChannel dst = new FileOutputStream(backupDB).getChannel();
            dst.transferFrom(src, 0, src.size());
            src.close();
            dst.close();
            Toast.makeText(getBaseContext(), backupDB.toString(),
                    Toast.LENGTH_LONG).show();

        }
    } catch (Exception e) {

        Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG)
                .show();

    }
}

文件已成功导出到具有其名称的文件夹这是我导入数据库的代码

int PICKFILE_RESULT_CODE = 1;
            Intent chooseFile = new Intent(Intent.ACTION_GET_CONTENT);
            chooseFile.setType("*/*");
            chooseFile = Intent.createChooser(chooseFile, "Choose a file");
            startActivityForResult(chooseFile, PICKFILE_RESULT_CODE);


@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent datas) {
    Uri uri = datas.getData();
    String filePath = uri.getPath();
    try {
        //Toast.makeText(this, ""+src, Toast.LENGTH_LONG).show();

        try {
            File sd = Environment.getExternalStorageDirectory();
            File data  = Environment.getDataDirectory();

            if (sd.canWrite()) {
                String  currentDBPath= "//data//" + "com.varcon.campus"
                        + "//databases//" + "CampusTime.db";
                String backupDBPath  = filePath;
                File  backupDB= new File(data, currentDBPath);
                File currentDB  = new File(sd, backupDBPath);

                FileChannel src = new FileInputStream(currentDB).getChannel();
                FileChannel dst = new FileOutputStream(backupDB).getChannel();
                dst.transferFrom(src, 0, src.size());
                src.close();
                dst.close();
                Toast.makeText(getBaseContext(), backupDB.toString(),
                        Toast.LENGTH_LONG).show();

            }
        } catch (Exception e) {

            Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG)
                    .show();

        }

        //new CustomMessage(getActivity(), "Database replaced sucessfully");
    } catch (Exception e) {
        e.printStackTrace();
        //CustomLog.showLogD("WORKING_STOP",e.getMessage());
    }
    super.onActivityResult(requestCode, resultCode, datas);
}

而且我在清单中有权限

Stacktrace：

2020-03-10 23:14:43.704 31088-31088/com.varcon.campus D/error: java.io.FileNotFoundException: /storage/emulated/0/Download/CampusTime (No such file or directory)

Answer 1

唯一要做的就是为所选的uri打开InputStream，而不是对文件使用FileInputStream。

InputStream is = getContentResolver().openInputStream(data.getData());

然后照常从流中读取。