Call a method when opening the application

I have the following class

public class ReadXlsx extends Activity {
    public TextView txtcoluna1;
    public TextView txtcoluna2;
    public TextView txtcoluna3;
    public TextView txtcoluna4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_read_xlsx);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); //Seta a tela para o layout retrato
        View botaoexemplo = findViewById(R.id.botaoexemplo);
        txtcoluna1 = (TextView) findViewById(R.id.txtcoluna1);
        txtcoluna2 = (TextView) findViewById(R.id.txtcoluna2);
        txtcoluna3 = (TextView) findViewById(R.id.txtcoluna3);  
        txtcoluna4 = (TextView) findViewById(R.id.txtcoluna4);  
    }

    public void ler(View view) throws IOException, BiffException, WriteException{

        //Setando Parâmetros
        Workbook workbook = Workbook.getWorkbook(new File("sdcard/AperamApps/DBQ/DBQmestre/speed.xls"));
        // Abrir Planilha
        Sheet sheet = workbook.getSheet(0);
        // Contas as linhas
        int linhas = sheet.getRows();
        //Informa o inicio da leitura
        System.out.println("Iniciando a leitura da planilha XLS:");
        for(int i = 0; i < linhas; i++){
        // Captura o valor das celulas ([Coluna], [linha])
            Cell b1 = sheet.getCell(1, 0);
            Cell b2 = sheet.getCell(1, 1);
            Cell b3 = sheet.getCell(1, 2);
            Cell b4 = sheet.getCell(1, 3);
            Cell b5 = sheet.getCell(1, 4);
            Cell b6 = sheet.getCell(1, 5);
            Cell b7 = sheet.getCell(1, 6);
            Cell b8 = sheet.getCell(1, 7);
            Cell b9 = sheet.getCell(1, 8);
        //Converter  valores das celulas para strings
            String as1 = b1.getContents();
            String as2 = b2.getContents();
            String as3 = b3.getContents(); 
            String as4 = b4.getContents(); 
            String as5 = b5.getContents(); 
            String as6 = b6.getContents(); 
            String as7 = b7.getContents(); 
            String as8 = b8.getContents(); 
            String as9 = b9.getContents(); 
        //Imprime os resutados

          txtcoluna1.setText("#1 | "+ as1);
          txtcoluna2.setText("#2 | "+ as2);
          txtcoluna3.setText("#3 | "+ as3);
          txtcoluna4.setText("#4 | "+ as4);

        // insere dados na planilha filtrada
        Workbook pfiltro = Workbook.getWorkbook(new File("sdcard/AperamApps/DBQ/DBQmestre/p-filtrada.xls"));
        WritableWorkbook outfiltro = Workbook.createWorkbook(new File("sdcard/AperamApps/DBQ/DBQmestre/out-filtrada.xls"), pfiltro);    
        pfiltro.close();
        Toast.makeText(getApplicationContext(), "Teste de função", Toast.LENGTH_SHORT).show();
        WritableSheet sheet1 = outfiltro.getSheet("filtro"); 
        WritableCell cell = sheet1.getWritableCell(0, 0); 
        WritableCell cella2 = sheet1.getWritableCell(0, 1); 
        WritableCell cella3 = sheet1.getWritableCell(0, 2); 
        WritableCell cella4 = sheet1.getWritableCell(0, 3); 
        WritableCell cella5 = sheet1.getWritableCell(0, 4);     
        WritableCell cella6 = sheet1.getWritableCell(0, 5); 
        WritableCell cella7 = sheet1.getWritableCell(0, 6); 
        WritableCell cella8 = sheet1.getWritableCell(0, 7); 
        WritableCell cella9 = sheet1.getWritableCell(0, 8); 

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cell; 
          l.setString(as1); 

        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella2; 
          l.setString(as2); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella3; 
          l.setString(as3); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella4; 
          l.setString(as4); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella5; 
          l.setString(as5); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella6; 
          l.setString(as6); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella7; 
          l.setString(as7); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella8; 
          l.setString(as8); 
        }

        if (cell.getType() == CellType.LABEL) 
        { 
          Label l = (Label) cella9; 
          l.setString(as9); 
        }

        // Escreve na planilha filtrada
        outfiltro.write();
        //Fecha a planilha de entrada de dados
        pfiltro.close();
        }
        workbook.close();
        }; 

        public void salvar1 (View view) throws IOException, BiffException, WriteException {

            Workbook workbook = Workbook.getWorkbook(new File("sdcard/AperamApps/DBQ/DBQmestre/speed.xls"));
            WritableWorkbook copy = Workbook.createWorkbook(new File("sdcard/AperamApps/DBQ/DBQmestre/speed2.xls"), workbook);


            WritableSheet sheet2 = copy.getSheet("speed"); 
            WritableCell cell = sheet2.getWritableCell(1, 2); 

            if (cell.getType() == CellType.LABEL) 
            { 
              Label l = (Label) cell; 
              l.setString("Teste"); 
            }
            copy.write(); 
            copy.close();
            workbook.close();

            Toast.makeText(getApplicationContext(), "Teste de função", Toast.LENGTH_SHORT).show();
        }
    }

How do I do that when the user opens the application, it automatically runs the "read" method?