Picocli命令行参数解析：通过明确定义选项的arity避免参数混淆

import picocli.CommandLine;
import picocli.CommandLine.Option;
import picocli.CommandLine.Parameters;
import java.util.List;

public class WordCountProblem implements Runnable {

    // 接受任意数量的文件名作为位置参数
    @Parameters(index="*", arity = "1..*", description= "The file(s) to count")
    public List<String> filenames;

    // 布尔型选项，默认arity为0 (flag)
    @Option(names = {"-c", "--countBytes"}, description = "Count the number of Bytes in the file")
    private Boolean countBytes = false;

    @Option(names= {"-w", "--countWords"}, description = "Count the number of Words in the file")
    private Boolean countWords = false;

    @Option(names = {"-l", "--countLines"}, description = "Count the number of lines in the file")
    private Boolean countLines = false;

    @Option(names = {"-m", "--countCharacters"}, description = "Count the number of characters in the file")
    private Boolean countCharacters = false;

    @Override
    public void run() {
        System.out.println("Files to process: " + filenames);
        System.out.println("Count Bytes: " + countBytes);
        System.out.println("Count Words: " + countWords);
        System.out.println("Count Lines: " + countLines);
        System.out.println("Count Characters: " + countCharacters);
        // 实际的统计逻辑会在此处实现
    }

    public static void main(String[] args) {
        new CommandLine(new WordCountProblem()).execute(args);