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Thread: Reading into an ArrayList from a text file

  1. #1
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    Default Reading into an ArrayList from a text file

    I am trying to take a text file and read it into the ArrayList I created. It should store the passengers name and the passenger's service class.

    The text file has the following format:
    James 1
    Sara 2
    Rita 1
    ....etc

    Here is my passenger class:
    public class Passenger
    {
        private int serviceClass;
        private String name;
     
        public Passenger(int sC, String n)
        {
            setServiceClass(sC);
            setName(n);
        }
     
        public void setServiceClass(int sC)
        {
            if(sC == 1 || sC == 2)
                serviceClass = sC;
            else
                System.out.println("Error");
        }
     
        public void setName(String n)
        {
            name = n;
        }
     
        public String getName()
        {
            return name;
        }
     
        public int getServiceClass()
        {
            return serviceClass;
        }
    }

    Here is my Train Class:
    import java.io.*;
    import java.util.Scanner;
    import java.util.ArrayList;
    public class Train
    {
        private ArrayList<Passenger> train;
        private double percent;
        private double revenue;
     
        public Train()
        {
            train = new ArrayList<Passenger>();
            File file = new File("Passengers.txt");
            Scanner input = new Scanner(file);
            String name; 
            int sClass;
     
            while(input.hasNext())
            {
                name = input.next();
                sClass = input.nextInt();
                Passenger pass = new Passenger(sClass, name);
                train.add(pass);
            }
            input.close();
        }
     
        double percent_first_class()
        {
            int count;
            int total;
            int serviceClass = pass.getServiceClass();
            if(serviceClass == 1)
            {
                count++;
                total++;
            }
            else
            {
                total++;
            }
            percent = count/total*100;
     
            return percent;
        }
     
        double train_revenue(double price_fC, double price_sC)
        {
            int nFC;
            int nSC;
            int serviceClass = pass.getServiceClass();
            if(serviceClass == 1)
            {
                nFC++;
            }
            else
            {
                nSC++;
            }
            revenue = (price_fC * nFC) + (price_sC * nSC);
            return revenue;
        }
     
        boolean pass_check()
        {
            ArrayList<Passenger> searchforpass = new ArrayList<Passenger>();
            for(Passenger currentPassenger : train)
            {
                if((currentPass.getName()).indexOf(searchString) != -1)
                    searchforpass.add(currentPass);
            }
            searchforpass.trimToSize();
            return true;
        }
    }

    I believe I am inputting the passengers into the ArrayList correctly (but not 100% sure). Then, in my percent_first_class method, I get an error when I try to compile saying that in my line:
    int serviceClass = pass.getServiceClass();
    It cannot find the variable pass

    The train_revenue method will return the total revenue of the train from given inputs in the parameters. I believe that is correct but once again it cannot find the variable pass.

    The pass_check method will allow the user to search for a passenger and will return true if the name is found, and false otherwise. I also believe that is correct.

    If you find mistakes, it would be greatly appreciated if you showed me how to fix them. I am very new to Java yet and am still learning. Thank you to all who help with this.


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Reading into an ArrayList from a text file

    cannot find the variable pass
    Is the variable: pass defined in the same scope (within the same enclosing {}s) as where it is being used?
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Reading into an ArrayList from a text file

    Pass is what I believe is being added to the ArrayList, which is defined in the default constructor. So it is not in the same scope but I do not know how to bring them out of that ArrayList to read the contents and perform the methods.

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Reading into an ArrayList from a text file

    how to bring them out of that ArrayList
    Look at the pass_check() method. It has code to extract Passenger objects from an arraylist.
    If you don't understand my answer, don't ignore it, ask a question.

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