java 使用字符串标记器从文本文件中设置创建数组？

Using string tokenizer to set create arrays out of a text file?

提问by ashamadelion

Hey. You may have recently seen a post by me looking for help, but I did it wrong before, so I am going to start fresh and begin at the basics.

嘿。您可能最近看到了我寻求帮助的帖子，但我之前做错了，所以我将重新开始并从基础开始。

I am trying to read a text file that looks like this:

我正在尝试读取如下所示的文本文件：

FTFFFTTFFTFT
3054 FTFFFTTFFTFT
4674 FTFTFFTTTFTF
... etc

FTFFTTFFTFT
3054 FTFFTTFFTFT
4674 FTFTFFTTTFTF
... 等

What I need to do is put the first line into a String as the answer key.

我需要做的是将第一行放入 String 作为答案键。

Next, I need to create an array with the student ID (the first numbers). Then, I need to create an array that is parallel to the student ID that contains the student's answers.

接下来，我需要使用学生 ID（第一个数字）创建一个数组。然后，我需要创建一个与包含学生答案的学生 ID 平行的数组。

Below is my code, and I can't quite figure out how to get it to work like this, and I was wondering if someone could help me out with it.

下面是我的代码，我不太清楚如何让它像这样工作，我想知道是否有人可以帮我解决这个问题。

public static String[] getData() throws IOException {
      int[] studentID = new int[50];
      String[] studentAnswers = new String[50];
      int total = 0;

      String line = reader.readLine();
      strTkn = new StringTokenizer(line);
      String answerKey = strTkn.nextToken();

      while(line != null) {
        studentID[total] = Integer.parseInt(strTkn.nextToken());
        studentAnswers[total] = strTkn.nextToken();
        total++;
      }
    return studentAnswers;
    }

So at the end of the day, the array structure should look like:

所以在一天结束时，数组结构应该如下所示：

studentID[0] = 3054
studentID[1] = 4674
... etc

studentID[0] = 3054
studentID[1] = 4674
...等

studentAnswers[0] = FTFFFTTFFTFT
studentAnswers[1] = FTFTFFTTTFTF

studentAnswers[0] = FTFFTTFFTFT
studentAnswers[1] = FTFTFFTTTFTF

Thanks :)

谢谢 ：）

采纳答案by Alex Ntousias

Assuming you have opened the file correctly for reading (because I can't see how the reader variable is initialized or the type of the reader) and the contents of the file are well-formed (according to what you expect), you have to do the following:

假设您已正确打开文件进行读取（因为我看不到 reader 变量是如何初始化的或读取器的类型）并且文件的内容格式正确（根据您的期望），您必须请执行下列操作：

  String line = reader.readLine();
  String answerKey = line;
  StringTokenizer tokens;
  while((line = reader.readLine()) != null) {
    tokens = new StringTokenizer(line);
    studentID[total] = Integer.parseInt(tokens.nextToken());
    studentAnswers[total] = tokens.nextToken();
    total++;
  }

Of course it would be best if you add some checks in order to avoid runtime errors (in case the contents of the file are not correct), e.g. try-catch clause around Integer.parseInt() (might throw NumberFormatException).

当然，最好添加一些检查以避免运行时错误（以防文件内容不正确），例如围绕 Integer.parseInt() 的 try-catch 子句（可能会抛出 NumberFormatException）。

EDIT: I just notice in your title that you want to use StringTokenizer, so I edited my code (replaced the split method with the StringTokenizer).

编辑：我只是在你的标题中注意到你想使用 StringTokenizer，所以我编辑了我的代码（用 StringTokenizer 替换了 split 方法）。

回答by McDowell

You may want to think about...

你可能想考虑...

• using the Scannerclass for tokenizing the input
• using collection types (such as ArrayList) instead of raw arrays - arrays have their uses, but they aren't very flexible; an ArrayListhas a dynamic length
• creating a class to encapsulate the student id and their answers - this keeps the information together and avoids the need to keep two arrays in sync

• 使用Scanner类来标记输入
• 使用集合类型（例如ArrayList）而不是原始数组 - 数组有其用途，但它们不是很灵活；一个ArrayList具有动态长度
• 创建一个类来封装学生 ID 和他们的答案 - 这将信息保持在一起并避免需要保持两个数组同步

---

---

Scanner input = new Scanner(new File("scan.txt"), "UTF-8");
List<AnswerRecord> test = new ArrayList<AnswerRecord>();
String answerKey = input.next();
while (input.hasNext()) {
  int id = input.nextInt();
  String answers = input.next();
  test.add(new AnswerRecord(id, answers));
}