Thread: Can't read really big files

Hey,

So basically I build a code to check lines on a .txt file and those likes compare a substring and change it to another saved string (always in the same position). Everything worked like a charm, no problem whatsoever, the messed up situation pops when I try to run the code on txt files with more than 2 million lines. This is definitely a problem because I need to run it on files with more than 10 million lines. What I tried to do was to save it on an ArrayList but it does not work, so Im lost here, been with this issue for more than 3 days, now Im getting to the point of dying. Here's the method call for the proccess:

      public void checaFechaSegunLugarUnico(String path, String archivo, int inicio, int fin) throws FileNotFoundException{
              jTextArea2.setText("");    
              try{
              FileReader fstream = new FileReader(path);
              //DataInputStream in = new DataInputStream(fstream);
              BufferedReader br = new BufferedReader(fstream);
              String strLine,primero, segundo, pivote,aux;
              int i = 0;
              ArrayList  almacem;
              almacem = new ArrayList();
              primero= "";
              jTextArea2.append("Hola\n");
              boolean bandera=true;
              while ((strLine = br.readLine()) != null){
                  almacem.add(strLine);
                  /*if(strLine.length() < fin){
                  aux= strLine;
                  jTextArea2.append(aux+"\n");
                  }
                  else{
                  pivote = strLine.substring(inicio,fin);
                  if(pivote.equals(primero)) {
                          aux= strLine;
                      }
                  else{
                  if (bandera == true){
                      primero = pivote;
                      bandera = false;
                      aux=strLine;
                  }  else{
 
                      aux = strLine.substring(0, inicio)+primero+strLine.substring(fin);
                      //aux = strLine.replaceAll(pivote, primero);
                  }
                  }
 
                  jTextArea2.append(aux+"\n");
 
              */}
                  jTextArea2.append("Salio\n");  
                  jTextArea2.append("Total leído: "+ almacem.size());
              //}
              /*SimpleDateFormat format = new SimpleDateFormat("yy-M-d");
              jTextArea1.append(primero+"\n");
              Date check = format.parse(primero);
              Calendar calendar = Calendar.getInstance();
              calendar.setTime(check);
              int dia = Integer.parseInt(primero.substring(8));
              int mes = calendar.get(Calendar.MONTH);
              int año = calendar.get(Calendar.YEAR);
              int ultDiaHab= obtenerUltimoDia(mes,año);
              if(dia == ultDiaHab){
                  jTextArea1.append("La fecha capturada en el archivo "+archivo+" si concuerda con el último dia habil del mes\n");
                  crearArchivo(path,archivo);
                  jTextArea2.setText("");
              }
              else {
                  jTextArea1.append("La fecha capturada en el archivo "+archivo+" no concuerda con el último dia habil del mes\n");
                  jTextArea2.setText("");
              }*/
 
              }catch (Exception e){
 
              }
 
   }

Any help will be greatly appreciated.

I second what Norm says. Also this type of code makes me nervous:

              }catch (Exception e){
 
              }

Please don't ignore exceptions. At least print a stacktrace:

              }catch (Exception e){
                  e.printStackTrace();  // *** added *** 
              }

First of all, thanks for your response. Now, Im supposed to get the size of the ArrayList almacem in jTextArea2 because I append the String there with jTextArea2.append("The size is " + almacem.size()) or at least I should get the first String that says jTextArea2.append("Salio\n"), but I aint getting any of those two in the Text Area, so my guessing is that the arrayList is not getting filled with the strLine values.