将2D数组写入CSV文件 [英] Writing a 2d array to a csv file

问题描述

我有一个具有2d数组的程序，我需要写入一个csv文件，但是我只需要写该数组的一个索引.我正在使用.get(0).set(4，newAmount)在第一个索引中设置一个值，但如果有必要，我需要将索引的所有值写入文件.

I have a program that has a 2d array and I need to write to a csv file but I only need to write one one index of the array. I'm using the .get(0).set(4, newAmount) to set a value in the first index but I need to write all values of the index to a file if that makes sense.

         fw = new FileWriter(FILE_NAME, true);
         bw = new BufferedWriter(fw);

        System.out.println("Enter the name of the person you want to change amount for");
       String changeName = FileUtility.getInput().nextLine();
       String newAmount;



        Scanner s = new Scanner(new File(FILE_NAME));
        String str = "";
        List<List<String>> list = new ArrayList<List<String>>();

        while (s.hasNext()) {
        list.add(Arrays.asList(s.nextLine().split(",")));
 }

 if (list.get(0).get(0).equalsIgnoreCase(changeName)) {
  System.out.println("Enter the new amount paid for the player");
  newAmount = FileUtility.getInput().nextLine();
  list.get(0).set(4, newAmount);
  //write to csv file here

推荐答案

将此代码放在代码底部.

put this code in bottom of your code.

String csv = list.stream()
    .map(row -> row.stream()
      .map(col -> col.toString())
        .collect(Collectors.joining(", ")))
    .collect(Collectors.joining("\n"));
writer.write(csv);

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