Question

我正在开发一个支持MaterialFileChooser的Livestream应用程序，但是我正在努力检查所选文本文件中的一行是否以“ h”开头，这些行（以h开头）是否应该存储在字符串中。

我尝试过：

public class Main {

    public static void main(String[] args){

        Scanner scanner = new Scanner(System.in);
        String oldString = scanner.next();

        String newString = changeVowels(oldString);

        System.out.println(newString);
        scanner.close();

    }

    private static String changeVowels(String oldString) {
        char[] characters = oldString.toCharArray();

        for (int i = 0; i < characters.length; i++) {
            switch (characters[i]) {
                case 'a':
                    characters[i] = 'e';
                    break;
                case 'e':
                    characters[i] = 'i';
                    break;
                case 'i':
                    characters[i] = 'o';
                    break;
                case 'o':
                    characters[i] = 'u';
                    break;
                case 'u':
                    characters[i] = 'a';
                    break;
                default:
                    break;
            }
        }

        return String.valueOf(characters);
    }
}

Answer 1

我不明白您的意思是“应该存储在字符串中”。如果您需要以“ h”开头的行，只需创建一个ArrayList字符串并将其保存在那里。

// Declare an ArrayList first 
private ArrayList<String> lineStore = new ArrayList<String>();

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1000 && resultCode == RESULT_OK) {
        String filePath = data.getStringExtra(FilePickerActivity.RESULT_FILE_PATH);

        try {
            BufferedReader br = new BufferedReader(new FileReader(filePath));
            String line;
            while ((line = br.readLine()) != null) {
               if (line.startsWith("h")) {
                   // Store the line in the ArrayList to be used later
                   lineStore.add(line); // That's what you meant? 
               }
            }

            br.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

如何检查txt文件中的一行是否在Android中以“ h”开头？

1 个答案: