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Thread: Sorting an ArrayList

  1. #1
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    Default Sorting an ArrayList

    Hello all,

    I am working on a program for school and I am having trouble with sorting my list. The numbers I receive in my output are correct, but not in ascending order as required.

    Here is my current code

    /*
     * To change this template, choose Tools | Templates
     * and open the template in the editor.
     */
    package gtt1_task2b;
     
    import java.util.Scanner;
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.FileReader;
    import java.io.File;
    import java.io.FileWriter;
    import java.io.PrintWriter;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Iterator;
    /**
     *
     */
    public class GTT1_Task2B{
     
          public static void main(String[] args) throws FileNotFoundException, IOException
        {
         // Prompt for the input and output file names
            Scanner properties = new Scanner(System.in);
            System.out.print("Input file: ");
            String inputFile = properties.next();
         // Create variables
            String id = null ;
            BufferedWriter pwfo = null;
            try{
            pwfo = new BufferedWriter(new FileWriter("C:\\Users\\zubeda.a.hemani\\Documents\\NetBeansProjects\\GTT1_Task2\\src\\gtt1_task2\\overview.txt"));
            } catch (IOException e){    
               }
               PrintWriter pwo = new PrintWriter(pwfo);
            File input = new File(inputFile);
            BufferedReader in = new BufferedReader(new FileReader(input));
            int count = 0;
            double sum = 0;
            //int i = 0;
            //ArrayList<Double> plist = new ArrayList<Double>();
     
      while ((id = in.readLine())!= null)     
                {
                count++;
                String[] proplist = id.split("[\\s}]");
                Double pvalue = Double.parseDouble(proplist[2]);
     
                for (int i=0; i < proplist.length; i++)
               {
                    sum+= pvalue;
                   }        
                }
                System.out.println("Total properties listed:  " + count);
                System.out.println("Total value of properties listed: " + sum + "\n");
                in.close();
     
                try {
            ArrayList<String> propids = new ArrayList<String>();       
            Scanner idlist = new Scanner((input));
              //print property ids
     
               while (idlist.hasNextLine())
               {               
                 id = idlist.nextLine();
                 String[] fields =id.split("[\\s}]");
                 String pids = (fields [0]);   
                       {     
                        Collections.sort(propids);
                        Iterator j =propids.iterator();
                        System.out.println(pids);
                        for (int i =0; i<6;i++)
                        in.close();
                       }
                    }
              //close Print Writer
                pwo.flush();
                pwo.close();
              }catch(Exception e){
                       }
                }
            }

    I am not sure where I am going wrong. Any assitance is greatly appreciated.

    Thank you.


  2. #2
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    Default Re: Sorting an ArrayList

    You have to debug the program to figure out where its execution differs from what you expect. Recommended reading: http://www.javaprogrammingforums.com...t-println.html
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  3. #3
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    Default Re: Sorting an ArrayList

    Thank you for the advice, I will try that.

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