Memory Problem in File Handling

Question

Hi friends,
I have created an application (linked with database) based on permutaion and combination problem which is really a very heavy application. Whle running the application, if i prefer Console as basic output source (System.out.println()), it works fine but if i use PrintWriter as a source and tranfers all my output to an excel file, created at runtime, ite will terminate with an exception: Out of Memory:. Please suggest me the solution to solve this issue. I have also tried -Xmx option but it also fails.
Regards,
Ankur

Answer 1

ok here is teh code for you dear:
try
                st_gsm = cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
                rs_gsm=st_gsm.executeQuery("select min(to_number(gsm)) gsmmin,max(to_number(gsm)) gsmmax from deckle where source='B'");
                rs_gsm.first();
                gsmMin=Integer.parseInt(rs_gsm.getString("gsmmin"));
                gsmMax=Integer.parseInt(rs_gsm.getString("gsmmax"));
                gsm=gsmMin;
                st_cnt = cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
                if(machine.equals("") || machine.equals(null))
                  JOptionPane.showMessageDialog(this,"Please enter the Machine first");
                else
                  rs_cnt=st_cnt.executeQuery("select count(1) records from deckle where source='B'");
                  rs_cnt.next();
                  records=Integer.parseInt(rs_cnt.getString("records"));
                  if(records>0)
                     * START: Creating a file for the deckle sheet
                     try
                      dt=new Date();
                      String filename=dt.toString().replace(" ","_");
                      filename=filename.replace("GMT+05:30_","");
                      filename=filename.replace(":","");
                      u = DeckleBoard.class.getResource("/DeckleBoard.class");
                      String path = new File(u.toString()).getParent();
                      path=(path.replace("file:\\",""));
                      System.out.println(path);
                      f=new File(path+"\\"+filename+".xls");
                      fw=new FileWriter(f,true);
                      pw = new PrintWriter(fw);
                     catch(Exception e) { e.printStackTrace(); }
                     * END: Creating a file for the deckle sheet
                    while(gsm<=gsmMax)
                      rs_cnt=st_cnt.executeQuery("select count(1) records from deckle where source='B' and gsm between " + (gsm-5) + " and " + (gsm+5));
                      rs_cnt.next();
                      records=Integer.parseInt(rs_cnt.getString("records"));
                      if(records>0)
                        str_sheet="select party,sheet_reel,length,width,sum(quantity) quantity,gsm,deckle_id " +
                                "from deckle " +
                                "where gsm between " + (gsm-5) + " and " + (gsm+5) +
                                " and sheet_reel='SHEET'" +
                                " and source='B'" +
                                " group by party,length,width,sheet_reel,gsm,deckle_id";
                        str_reel="select party,sheet_reel,length,sum(quantity) quantity,gsm,deckle_id " +
                                "from deckle " +
                                "where gsm between " + (gsm-5) + " and " + (gsm+5) +
                                " and sheet_reel='REEL' " +
                                " and source='B'" +
                                " group by party,length,sheet_reel,gsm,deckle_id";
                        str_mix="select party,sheet_reel,length,nvl(width,0) width,sum(quantity) quantity,gsm,deckle_id " +
                                "from deckle " +
                                "where gsm between " + (gsm-5) + " and " + (gsm+5) +
                                " and source='B'" +
                                " group by party,length,width,sheet_reel,gsm,deckle_id";
                        //System.out.println(str_sheet);
                        showCombinations();
                        System.out.println("\n");
                      gsm=gsm+5;
                    System.out.println("Total Quantity = "+Math.round(tot_qty*10.0f)/10.0f);
                    JOptionPane.showMessageDialog(this,"Process Finished");
                    System.out.println("============================================================");
                    System.out.println("Pending Sizes");
                    System.out.println("============================================================");
                    fill_pending_sizes_S_S();
                    System.out.println("Pending3: "+dataGSMS.length);
                    int v;
                    for(v=0;v<dataGSMS.length;v++)
                     System.out.println("Hello : \t");
                     System.out.print(typeGSMS[v]+"\t");
                     System.out.print(dataGSMS[v]+" * ");
                     System.out.print(widthGSMS[v]+"\t");
                     System.out.print(wtGSMS[v]+"\t");
                     System.out.print(GSMS[v]+"\t");
                     System.out.println(partyGSMS[v]);
                    System.out.println("Pending4: "+dataGSMS.length);
                    JOptionPane.showMessageDialog(this,"Process Finished2");
                    pw.close();
                  else
                    JOptionPane.showMessageDialog(this,"Recordset is empty...");
              catch(Exception e1)
              }May this help you in solving. here, showCombinations() is the method which runs for the actual COMBINATIONS logic.