How to read sdcard CSV file?

Currently I read a csv file from the assets folder with the following code:

    String arquivoCSV = "clientes.csv";
    AssetManager manager = context.getAssets();
    InputStream inputStream = null;

    try{
        inputStream = manager.open(arquivoCSV);
    }catch (IOException e){
        e.printStackTrace();
    }

    BufferedReader buffer = new BufferedReader(new InputStreamReader(inputStream));

But I need to update this file constantly, and through the assets folder it is not possible, I need to read the sscard's CSV file, does anyone have any idea how to do it?

I used the code, but now it does not identify any lines, it follows the code:

    File path = Environment.getExternalStorageDirectory();
    File file = new File(path, "/produtos.csv");
    FileInputStream fileInputStream = new FileInputStream(file);

    BufferedReader buffer = new BufferedReader(new InputStreamReader(fileInputStream));
    String line = "";
    conn.beginTransaction();
    conn.delete("PRODUTOS", "1", null);
        try{

            while ((line = buffer.readLine())!= null){
                String[] colunas = line.split(",");
                    if (colunas.length != 6){
                        Log.d("CSVParder","Ignorando linhas ruins");
                        continue;
                    }
                ContentValues cv = new ContentValues();
                cv.put("COD_PRODUTO",colunas[0].trim());
                cv.put("NOME",colunas[1].trim());
                cv.put("DESCR",colunas[2].trim());
                cv.put("GRUPO",colunas[3].trim());
                cv.put("SUBGRUPO",colunas[4].trim());
                cv.put("MEDIDA",colunas[5].trim());

                conn.insert("PRODUTOS",null,cv);

            }

        }catch (IOException e){
            e.printStackTrace();
        }
    conn.setTransactionSuccessful();
    conn.endTransaction();
    Toast.makeText(context,"Produtos atualizados com sucesso!",Toast.LENGTH_LONG).show();