java - 如何仅选择性地从 .txt 文件中读取数字和/或单词？

Question

我有一个简单的 .txt 文件(“theFile.txt”)，其格式如下，其中左列是 lineNumber，右列是 word:

5     today
2     It's
1     "
4     sunny
3     a
6     "

对于这个 txt 文件，我使用两个单独的方法来每个获取仅数字和仅字符串，再加上另一种方法来扫描文件并将每个 lineNumber 和 word 放入双链表 DLL 中:

  String fileName = "theFile.txt";

  public int getNumberOnly() {
       int lineNumber;

       //code to only get the lineNumber but NOT the words
       //This is as far as I got and I need help on this part

       return lineNumber;
  }

  public String getWordsOnly() {
       String words;

       //code to only get the words but NOT the lineNumber
       //This is as far as I got and I need help on this part

       return words;
  }

  public void readAndPrintWholeFile(String fileName){

          String fileContents = new String();
          File file = new File("theFile.txt");
          Scanner scanner = new Scanner(new FileInputStream(fileName));
          DLL<T> list = new DLL<T>();

         //Print each lineNumber and corresponding words for example
         // 5   Today
         // 2   It's

         while (scanner.hasNextLine())
         {
              fileContents = scanner.nextLine();
              System.out.println(list.getNumbersOnly() + " " +  list.getWordOnly());  
              //prints the lineNumber then space then the word
         }
  }

  //I already have all DLL accessors and mutators such as get & set next/previous nodes here, etc.

我不知道如何为 getNumbersOnly() 和 getWordOnly() 编写方法体

我已经尽力做到这一点。感谢您的帮助。

Answer 1

public static void readAndPrintWholeFile(String filename) throws FileNotFoundException {
    String fileContents;
    File file = new File(filename);
    Scanner scanner = new Scanner(new FileInputStream(file));
    Map<String, String> map = new HashMap<>();

    while (scanner.hasNextLine()) {
        try {
            fileContents = scanner.nextLine();
            String[] as = fileContents.split(" +");
            map.put(as[0], as[1]);
            System.out.println(as[0] + " " + as[1]);
        } catch (ArrayIndexOutOfBoundsException e) {
            //If some problam with File formate e.g. number without word
        }
    }
}

您可以通过多种方式做到这一点，其中之一就是聆听。Hera 我没有实现 getNumberOnly() 和 getWordsOnly() 方法，并且我没有 DLL 实现，因此将数据放入 map(HashMap) 中。