java - 尝试创建一个自动创建数组并用字节值填充它的程序

Question

我可以有一个包含以下内容的pattern.txt 文件:

45 56

45 56 56 56 e6

只有 2 行(需要 2 个数组)。

但是，我可以有一个包含 3 个不同行的文件(需要 3 个数组)。

45 56

45 56 56 56 e6

43 e6

我需要一个程序，它可以自动创建一个包含所需元素的数组，并用分隔符(空格)分隔的每一行填充它。

例如，

byte[] pattern1= new byte[] { 45, 46 };
byte[] pattern2= new byte[] { 45, 56, 56, e6};
byte[] pattern3= new byte[] { 43, e6 };

它还需要将数组从十六进制转换为字节。

怎么可能做这样的事情？

我目前有这段代码，它按预期输出到控制台，但我需要将其添加到数组中。

public void loadPattern() {

    loadedPatterns.clear();

    File file = new File(fileName);

    int elements = 0;

    try {
        // Here we use the Scanner class to read file content line-by-line.
        Scanner scanner = new Scanner(file);
        while (scanner.hasNextLine()) {
            String line = scanner.nextLine();

            // From the above line of code we got a line from the file
            // content. Now we want to split the line with a space as the
            // character delimiter.
            Scanner lineScanner = new Scanner(line);
            lineScanner.useDelimiter(" ");
            while (lineScanner.hasNext()) {
                // Get each splitted data from the Scanner object and print
                // the value.
                elements++;

                String part = lineScanner.next();
                System.out.print(part + " ");
            }
            System.out.println();
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}

Answer 1

public class LineMapper {
    // assuming you have this list
    private List<Byte[]> loadedPatterns = new ArrayList<>();
    private File patternsFile = new File("pattern.txt");

    public void loadPattern() {
        loadedPatterns.clear();
        try (Stream<String> stream = Files.lines(patternsFile.toPath())) {
            stream.map(LineMapper::lineToArray).forEach(loadedPatterns::add);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static Byte[] lineToArray(String line) {
        return Stream.of(line.split("\\s+")).map(LineMapper::hexToByte).toArray(Byte[]::new);
    }

    private static byte hexToByte(String hex) {
        return (byte) ((Character.digit(hex.charAt(0), 16) << 4) + Character.digit(hex.charAt(1), 16));
    }
}