//An example to manipulate the fields in a csv file then redirect the result to an
//output file to generate a report.
import java.io.*;
import java.util.*;

public class File_Writer_csv {
  public static void main(String[] args) throws IOException{
     BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
     File output = new File("output.csv");  //create a new file for output.
     output.createNewFile();  //create a new file if necessary.
     BufferedWriter out = new BufferedWriter(new FileWriter(output));
     String fname = "Details.csv";
	 String[] st = new String[5];  //There are 5 fields in each record of the Details.csv file.

     BufferedReader in = null;
     try{
        in = new BufferedReader(new FileReader(fname));
     }
     catch(Exception e){
        System.out.println("Unable to open the specified file!");
        System.out.println(e);
        System.exit(1);
     }

//  StringTokenizer st;
  int total = 1, linenum = 0, qty = 0;
  double price_unit = 0., sum = 0.;

  try{
     in = new BufferedReader(new FileReader(fname));
     String  line = in.readLine();

     String st4 = "Description,Unit price,Quantity,Total";  //Print our OWN column HEADER!!! (NOT from the .csv file)";

     System.out.println(st4);

     boolean answer = false;
     BufferedReader inbuf = new BufferedReader(new InputStreamReader(System.in));
     char ans = 'n';
     if(output.exists()){
       System.out.println("File already exists, overwrite it anyway?");
       ans = inbuf.readLine().charAt(0);
       }

     if( ans == 'y' || ans == 'Y')
       out.write(st4 + "\n"); //write the column headers to the output file.
     else
       System.exit(1);


	 line = in.readLine(); //skip the column header.
     while(line != null){
		 st = line.split(",");

           System.out.print(st[0] + "\t");
           out.write(st[1] + ",");  //write the product's name to the output file.\

           price_unit = Double.parseDouble(st[2]);  //get the unit price.
           System.out.print("$" + price_unit + ",");

           out.write("$" + st[2] + ",");  //write the per unit price to the output file.
           qty = Integer.parseInt(st[3]);  //get the quantity.
           System.out.print(qty);

           sum = price_unit*qty;
           sum = (double) Math.round(sum*100)/100;
           System.out.println(",$" + sum);//round to 2 decimals.
           out.write(qty + ",$" + sum + "\n");  //write the quantity & the sum to the output file.
       line = in.readLine();
       }
   }
   catch(Exception e){
     System.out.println(e);
     System.exit(0);
     }

     out.close();
  }  //end of main()
}  //end of class File_IO5{}

/* Here is the "Details.csv" file---------
Order ID,Product,Unit Price,Quantity,Discount
10248,Queso Cabrales,14.00 ,12,0.00%
10248,Singaporean Hokkien Fried Mee,9.80 ,10,0.00%
10248,Mozzarella di Giovanni,34.80 ,5,0.00%
10249,Tofu,18.60 ,9,0.00%
10249,Manjimup Dried Apples,42.40 ,40,0.00%
10250,Jack's New England Clam Chowder,7.70 ,10,0.00%
10250,Manjimup Dried Apples,42.40 ,35,15.00%
10250,Louisiana Fiery Hot Pepper Sauce,16.80 ,15,15.00%
10251,Gustaf's Knäckebröd,16.80 ,6,5.00%
10251,Ravioli Angelo,15.60 ,15,5.00%
10251,Louisiana Fiery Hot Pepper Sauce,16.80 ,20,0.00%
10252,Sir Rodney's Marmalade,64.80 ,40,5.00%
10252,Geitost,2.00 ,25,5.00%
10252,Camembert Pierrot,27.20 ,40,0.00%
10253,Gorgonzola Telino,10.00 ,20,0.00%
10253,Chartreuse verte,14.40 ,42,0.00%
10253,Maxilaku,16.00 ,40,0.00%
10254,Guaraná Fantástica,3.60 ,15,15.00%
10254,Pâté chinois,19.20 ,21,15.00%
10254,Longlife Tofu,8.00 ,21,0.00%
10255,Chang,15.20 ,20,0.00%
10255,Pavlova,13.90 ,35,0.00%
10255,Inlagd Sill,15.20 ,25,0.00%
10255,Raclette Courdavault,44.00 ,30,0.00%
10256,Perth Pasties,26.20 ,15,0.00%
10256,Original Frankfurter grüne Soße,10.40 ,12,0.00%
10257,Schoggi Schokolade,35.10 ,25,0.00%
10257,Chartreuse verte,14.40 ,6,0.00%
10257,Original Frankfurter grüne Soße,10.40 ,15,0.00%
10258,Chang,15.20 ,50,20.00%
10258,Chef Anton's Gumbo Mix,17.00 ,65,20.00%
10258,Mascarpone Fabioli,25.60 ,6,20.00%
10259,Sir Rodney's Scones,8.00 ,10,0.00%
10259,Gravad lax,20.80 ,1,0.00%
10260,Jack's New England Clam Chowder,7.70 ,16,25.00%
10260,Ravioli Angelo,15.60 ,50,0.00%
10260,Tarte au sucre,39.40 ,15,25.00%
10260,Outback Lager,12.00 ,21,25.00%
10261,Sir Rodney's Scones,8.00 ,20,0.00%
10261,Steeleye Stout,14.40 ,20,0.00%
10262,Chef Anton's Gumbo Mix,17.00 ,12,20.00%
10262,Uncle Bob's Organic Dried Pears,24.00 ,15,0.00%
10262,Gnocchi di nonna Alice,30.40 ,2,0.00%
10263,Pavlova,13.90 ,60,25.00%
10263,Guaraná Fantástica,3.60 ,28,0.00%
10263,Nord-Ost Matjeshering,20.70 ,60,25.00%
10263,Longlife Tofu,8.00 ,36,25.00%
10264,Chang,15.20 ,35,0.00%
10264,Jack's New England Clam Chowder,7.70 ,25,15.00%
10265,Alice Mutton,31.20 ,30,0.00%
10265,Outback Lager,12.00 ,20,0.00%
10266,Queso Manchego La Pastora,30.40 ,12,5.00%
10267,Boston Crab Meat,14.70 ,50,0.00%
10267,Raclette Courdavault,44.00 ,70,15.00%
10267,Lakkalikööri,14.40 ,15,15.00%
10268,Thüringer Rostbratwurst,99.00 ,10,0.00%
10268,Mozzarella di Giovanni,27.80 ,4,0.00%
10269,Geitost,2.00 ,60,5.00%
10269,Mozzarella di Giovanni,27.80 ,20,5.00%
10270,Inlagd Sill,15.20 ,30,0.00%
10270,Ipoh Coffee,36.80 ,25,0.00%
10271,Geitost,2.00 ,24,0.00%
10272,Sir Rodney's Marmalade,64.80 ,6,0.00%
10272,Gorgonzola Telino,10.00 ,40,0.00%
10272,Mozzarella di Giovanni,27.80 ,24,0.00%
10273,Ikura,24.80 ,24,5.00%
10273,Gorgonzola Telino,10.00 ,15,5.00%
10273,Geitost,2.00 ,20,0.00%
10273,Boston Crab Meat,14.70 ,60,5.00%
10273,Lakkalikööri,14.40 ,33,5.00%
10274,Fløtemysost,17.20 ,20,0.00%
10274,Mozzarella di Giovanni,27.80 ,7,0.00%
10275,Guaraná Fantástica,3.60 ,12,5.00%
10275,Raclette Courdavault,44.00 ,6,5.00%
10276,Ikura,24.80 ,15,0.00%
10276,Konbu,4.80 ,10,0.00%
10277,Rössle Sauerkraut,36.40 ,20,0.00%
10277,Tarte au sucre,39.40 ,12,0.00%
10278,Gula Malacca,15.50 ,16,0.00%
10278,Raclette Courdavault,44.00 ,15,0.00%
10278,Vegie-spread,35.10 ,8,0.00%
10278,Röd Kaviar,12.00 ,25,0.00%
10279,Alice Mutton,31.20 ,15,25.00%
10280,Guaraná Fantástica,3.60 ,12,0.00%
10280,Pâté chinois,19.20 ,20,0.00%
10280,Rhönbräu Klosterbier,6.20 ,30,0.00%
10281,Teatime Chocolate Biscuits,7.30 ,1,0.00%
10281,Guaraná Fantástica,3.60 ,6,0.00%
10281,Steeleye Stout,14.40 ,4,0.00%
10282,Nord-Ost Matjeshering,20.70 ,6,0.00%
10282,Ravioli Angelo,15.60 ,2,0.00%
10283,Genen Shouyu,12.40 ,20,0.00%
10283,Teatime Chocolate Biscuits,7.30 ,18,0.00%
10283,Camembert Pierrot,27.20 ,35,0.00%
10283,Mozzarella di Giovanni,27.80 ,3,0.00%
10284,Schoggi Schokolade,35.10 ,15,25.00%
10284,Gula Malacca,15.50 ,21,0.00%
10284,Camembert Pierrot,27.20 ,20,25.00%
10284,Laughing Lumberjack Lager,11.20 ,5,25.00%
10285,Chai,14.40 ,45,20.00%
10285,Boston Crab Meat,14.70 ,40,20.00%
10285,Perth Pasties,26.20 ,36,20.00%
10286,Steeleye Stout,14.40 ,100,0.00%
10286,Tarte au sucre,39.40 ,40,0.00%
10287,Pavlova,13.90 ,40,15.00%
10287,Sasquatch Ale,11.20 ,20,0.00%
10287,Spegesild,9.60 ,15,15.00%
10288,Tourtière,5.90 ,10,10.00%
10288,Scottish Longbreads,10.00 ,3,10.00%
10289,Aniseed Syrup,8.00 ,30,0.00%
10289,Wimmers gute Semmelknödel,26.60 ,9,0.00%
10290,Chef Anton's Gumbo Mix,17.00 ,20,0.00%
10290,Thüringer Rostbratwurst,99.00 ,15,0.00%
10290,Maxilaku,16.00 ,15,0.00%
10290,Original Frankfurter grüne Soße,10.40 ,10,0.00%
10291,Konbu,4.80 ,20,10.00%
10291,Gula Malacca,15.50 ,24,10.00%
10291,Manjimup Dried Apples,42.40 ,2,10.00%
10292,Sir Rodney's Marmalade,64.80 ,20,0.00%
10293,Carnarvon Tigers,50.00 ,12,0.00%
10293,Guaraná Fantástica,3.60 ,10,0.00%
10293,Vegie-spread,35.10 ,5,0.00%
10293,Rhönbräu Klosterbier,6.20 ,6,0.00%
10294,Chai,14.40 ,18,0.00%
10294,Alice Mutton,31.20 ,15,0.00%
10294,Ipoh Coffee,36.80 ,15,0.00%
10294,Camembert Pierrot,27.20 ,21,0.00%
10294,Rhönbräu Klosterbier,6.20 ,6,0.00%
10295,Gnocchi di nonna Alice,30.40 ,4,0.00%
10296,Queso Cabrales,16.80 ,12,0.00%
10296,Pavlova,13.90 ,30,0.00%
10296,Gudbrandsdalsost,28.80 ,15,0.00%
10297,Chartreuse verte,14.40 ,60,0.00%
10297,Mozzarella di Giovanni,27.80 ,20,0.00%
10298,Chang,15.20 ,40,0.00%
10298,Inlagd Sill,15.20 ,40,25.00%
10298,Raclette Courdavault,44.00 ,30,25.00%
10298,Tarte au sucre,39.40 ,15,0.00%
10299,Teatime Chocolate Biscuits,7.30 ,15,0.00%
10299,Outback Lager,12.00 ,20,0.00%
10300,Louisiana Hot Spiced Okra,13.60 ,30,0.00%
10300,Scottish Longbreads,10.00 ,20,0.00%
10301,Boston Crab Meat,14.70 ,10,0.00%
10301,Gnocchi di nonna Alice,30.40 ,20,0.00%
10302,Alice Mutton,31.20 ,40,0.00%
10302,Rössle Sauerkraut,36.40 ,28,0.00%
10302,Ipoh Coffee,36.80 ,12,0.00%
10303,Boston Crab Meat,14.70 ,40,10.00%
10303,Louisiana Fiery Hot Pepper Sauce,16.80 ,30,10.00%
10303,Scottish Longbreads,10.00 ,15,10.00%
10304,Maxilaku,16.00 ,30,0.00%
10304,Raclette Courdavault,44.00 ,10,0.00%
10304,Fløtemysost,17.20 ,2,0.00%
10305,Carnarvon Tigers,50.00 ,25,10.00%
*/