如何將從文件中讀取的值復制到數組列表中

Question

我正在嘗試解決一個問題，該問題將一個文件作為輸入，其中包含 5 個國家/地區的數據，例如：銷售 yadayada 的利潤項目......我試圖從文件中讀取並計算每個國家/地區的總利潤。 目前，我已經從文件中讀取了輸入，找到了國家名稱的索引和國家的利潤（每個國家和利潤在整個 CSV 文件中都在同一個索引中）。 然后我開始查看每條線路並比較該線路是否是 5 個國家/地區之一。 如果該行的索引表示國家名稱為“美國”，則應將包含利潤的索引添加到國家/地區列表中。 我現在的問題是，我試圖為每個國家/地區創建的數組列表存儲了所有利潤的值（就像我想要的那樣）但隨后不斷重復，最終的數組列表由不同的數組組成（我不不知道怎么說）。

列表看起來像 [1234 12341 1241231 1231 3123 124123 123 123 123 ], [3123 123 112358723 8398172 8123 ], [].....

當我希望它們看起來像 [1234, 1234,1234,1234,1234,1234]

我不知道為什么數組列表一遍又一遍地將值復制到不同的索引中，但這基本上是我問題的症結所在。

從那里我應該獲取這些值並將它們總結為每個國家，然后將它們打印到我覺得我可以處理的輸出文件中。

我的 CSV 文件看起來像這樣，

Segment,Country, Product , Discount Band ,Units Sold, Manufacturing Price , Sale Price , Gross Sales , Discounts ,  Sales , COGS , Profit ,Date,Month Number, Month Name ,Year
Government,Canada, Carretera , None ,1618.5,3,20,32370,0,32370,16185,16185,1/1/2014,1, January ,2014
Government,Germany, Carretera , None ,1321,3,20,26420,0,26420,13210,13210,1/1/2014,1, January ,2014
Midmarket,France, Carretera , None ,2178,3,15,32670,0,32670,21780,10890,1/6/2014,6, June ,2014
Midmarket,Germany, Carretera , None ,888,3,15,13320,0,13320,8880,4440,1/6/2014,6, June ,2014
Midmarket,Mexico, Carretera , None ,2470,3,15,37050,0,37050,24700,12350,1/6/2014,6, June ,2014
Government,Germany, Carretera , None ,1513,3,350,529550,0,529550,393380,136170,1/12/2014,12, December ,2014
Midmarket,Germany, Montana , None ,921,5,15,13815,0,13815,9210,4605,1/3/2014,3, March ,2014

到目前為止我的代碼看起來像：

public static void main(String[] args) throws IOException {
    Scanner in = new Scanner(new File("sample-csv-file-for-testing-fixed.csv"));
    PrintWriter pw = new PrintWriter(new File("Output.csv"));

    // gets first line of file
    String firstline = in.nextLine();
    firstline.trim();
    String data = firstline.replaceAll(" ", "");
    String[] header = data.split(",");

    // find index of Country and Profit and store them into variables
    String country = "Country";
    String profit = "Profit";

    int index1 = 0, index2 = 0;
    for (int i = 0; i < header.length; i++) {
        if (header[i].equals(country)) {
            index1 = i;
        }
    }
    for (int i = 0; i < header.length; i++) {
        if (header[i].equals(profit)) {
            index2 = i;
        }
    }
    //System.out.println(index1+" "+index2);

    // arrays for each country
    ArrayList<String> USA = new ArrayList<String>();
    ArrayList<String> France = new ArrayList<String>();
    ArrayList<String> Germany = new ArrayList<String>();
    ArrayList<String> Mexico = new ArrayList<String>();
    
    while (in.hasNextLine()) {
        String line = in.nextLine();
        String nextline = line.replaceAll(" ", "");
        String[] values = nextline.split(",");
        // find what country the line has

        if (values[index1].equals("United States of America")) {
            USA.add(values[index2]);
        } else if (values[index1].equals("France")) {
            France.add(values[index2]);
        } else if (values[index1].equals("Germany")) {
            Germany.add(values[index2]);
        } else if (values[index1].equals("Mexico")) {
            Mexico.add(values[index2]);
        }

        // test prints
        // System.out.print(USA );
        //System.out.print("\n" + France + " ");
        //System.out.print("\n" + Germany + " ");
        //System.out.println("\n"+ Mexico + " ");    
    }
}

Answer 1

可能比我做的更好一點，但我最終想通了

   public static void main(String[]args)throws IOException{

    Scanner in = new Scanner(new File("sample-csv-file-for-testing-fixed.csv"));
    PrintWriter pw = new PrintWriter(new File("Output.csv"));

    // gets first line of file
    String firstline = in.nextLine();
    firstline.trim();
    String data = firstline.replaceAll(" ","");
    String[] header = data.split(",") ;


    // find index of Country and Profit and store them into variables
    String country = "Country";
    String profit = "Profit";

    int index1 =0 , index2=0;
    for(int i = 0;i < header.length;i++){
        if(header[i].equals(country)){
          index1 = i;
        }
    }
    for(int i = 0;i<header.length;i++){
        if(header[i].equals(profit)){
         index2 = i;
        }
    }
    
    
    // Create arraylists for each country
    ArrayList<String> USA = new ArrayList<String>();  
    ArrayList<String> France = new ArrayList<String>();
    ArrayList<String> Germany = new ArrayList<String>();
    ArrayList<String> Mexico = new ArrayList<String>();
    ArrayList<String> Canada = new ArrayList<String>();

    while( in.hasNextLine()){
         String line = in.nextLine();
         String nextline = line.replaceAll(" ","");
         String[] values = nextline.split(",");
         
         //Finding lines with each country
        if(values[index1].contains("United")){
         USA.add(values[index2]);
        }
         else if(values[index1].equals("France")){
           France.add(values[index2]);
        }
         else if(values[index1].equals("Germany")){
          Germany.add(values[index2]);
         }
        else if(values[index1].equals("Mexico")){
        Mexico.add(values[index2]);
        }
        else if(values[index1].equals("Canada")){
            Canada.add(values[index2]);
        }
    }
    

    // call method and store values into double array lists;
    ArrayList<Double> france_results = getIntegerArray(France);
    ArrayList<Double> germany_results = getIntegerArray(Germany);
    ArrayList<Double> USA_results = getIntegerArray(USA);
    ArrayList<Double> mexico_results = getIntegerArray(Mexico);
    ArrayList<Double> canada_results = getIntegerArray(Canada);

    // call method to sum values in ArrayLists

    double sumUSA = getSum(USA_results);
    double sumFrance = getSum(france_results);
    double sumGermany = getSum(germany_results);
    double sumMexico = getSum(mexico_results);
    double sumCanada = getSum(canada_results);

    // Print to Output.CSV file
    pw.print("France , " + sumFrance + "\n" 
    + "Germany ," + sumGermany + "\n"
    + "Canada ," + sumCanada + "\n"
    + "United States of America ," + sumUSA + "\n"
    + "Mexico , "+ sumMexico);
    
    pw.close();

}


// Method to conver String ArrayList to Integer ArrayLists
public static ArrayList<Double> getIntegerArray(ArrayList<String> stringArray){

    ArrayList<Double> values = new ArrayList<Double>();
    for(String stringValue : stringArray){
        values.add(Double.parseDouble(stringValue));
    }
    return values;



}
// method to sum the index of each ArrayList
public static double getSum(ArrayList<Double> doubleArray){
    double sum = 0;
    for(int i = 0; i< doubleArray.size();i++){
        sum = sum + doubleArray.get(i);
    }
    return sum;
}