Question

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;


public class logBook
{
   public static void main(String[] args) throws FileNotFoundException
      {  
         File inputFile = new File("C:\\Users\\Nick Tate\\Desktop\\Log.txt");
       try{
         Scanner in = new Scanner(inputFile);
            while(in.hasNextLine())
               {
                   in.useDelimiter(";");

                 String clientName = in.next();
                 String serviceCost = in.next();
                 String serviceSold = in.next();
                 String serviceDate = in.next();
                 double cost = Double.parseDouble(serviceCost.trim());
               System.out.print(clientName);
                 System.out.printf("%8.2f", cost);
                 System.out.print(serviceSold);
                 System.out.print(serviceDate); 

               }
            in.close();
            }
            catch(FileNotFoundException e){
               e.printStackTrace();
            }  


      }
}

输出：

 - John 25.00 Dinner Aug 12 2013 
 - Bob  200.00 Conference Sep 11 2013
 - Clara  450.00 Lodging Oct 25 2013
 - Jamie  900.00 Lodging Oct 28 2013
 - Rachel   89.00 Dinner Nov 11 2013
 - Richard 1000.00 Conference Dec 17 2013
 - Nick 2500.00 Dinner Jan 05 2014

到目前为止，我已成功读取了我文件中的每个项目，并解析了相应的变量。我现在需要总计单独服务类别的费用（即晚餐，会议等）。我该怎么做呢？我想添加if（）子句检查每个服务，如

 if(serviceSold.equals("Dinner")
    {  int sum = 0
       dinnerTotal = sum++
    }

但是，我如何将相应的价格添加到该类别？任何指导？我最终需要将这些总数写入另一个名为outputLogBook.text的文件。

Answer 1

您可以执行以下操作：

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Map;


public class logBook
{
   public static void main(String[] args) throws FileNotFoundException
   {  
      File inputFile = new File("C:\\Users\\Nick Tate\\Desktop\\Log.txt");
      try
      {
         Scanner in = new Scanner( inputFile );
         Map<String, Double> services = new HashMap<String, Double>();

         while( in.hasNextLine() )
         {
            in.useDelimiter(";");

            String clientName = in.next();
            String serviceCost = in.next();
            String serviceSold = in.next();
            String serviceDate = in.next();
            Double cost = Double.parseDouble (serviceCost.trim() );
            System.out.print(clientName);
            System.out.printf("%8.2f", cost);
            System.out.print(serviceSold);
            System.out.print(serviceDate);

            if ( services.containsKey( serviceSold ) )
            {
              services.put( serviceSold, (Double) services.get( serviceSold ) + cost );
            }
            else
            {
              services.put( serviceSold, cost );
            } 
         }

         for( Map.Entry<String, Double> entry : services.entrySet() ) 
         {
             System.out.println(entry);
         }
         in.close();
      }
      catch(FileNotFoundException e)
      {
         e.printStackTrace();
      }  
   } 
}

如何从文件中累计服务和服务总成本？

1 个答案: