Java利用Picocli开发一个简化命令行工具

<dependency>
    <groupId>info.picocli</groupId>
    <artifactId>picocli</artifactId>
    <version>4.7.4</version>
</dependency>

import picocli.CommandLine;
import picocli.CommandLine.Command;
import picocli.CommandLine.Option;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.concurrent.Callable;

@Command(name = "filetool", version = "FileTool 1.0",
        description = "一个用于文件操作的命令行工具",
        mixinStandardHelpOptions = true)
public class FileTool implements Callable<Integer> {

    @Option(names = {"-p", "--path"}, description = "文件路径", required = true)
    private String filePath;

    @Option(names = {"-c", "--count-lines"}, description = "统计文件行数")
    private boolean countLines;

    @Option(names = {"-r", "--read-content"}, description = "读取并输出文件内容")
    private boolean readContent;

    @Override
    public Integer call() throws Exception {
        if (countLines) {
            long lineCount = Files.lines(Paths.get(filePath)).count();
            System.out.println("文件行数: " + lineCount);
        }

        if (readContent) {
            String content = new String(Files.readAllBytes(Paths.get(filePath)));
            System.out.println("文件内容:\n" + content);
        }

        return 0;
    }

    public static void main(String[] args) {
        int exitCode = new CommandLine(new FileTool()).execute(args);
        System.exit(exitCode);
    }
}

java -jar filetool.jar --help

java -jar filetool.jar -p sample.txt -c

java -jar filetool.jar -p sample.txt -r

@Command(name = "filetool", description = "文件工具", mixinStandardHelpOptions = true, subcommands = {
        FileReadCommand.class,
        FileCountCommand.class
})
public class FileTool {
    public static void main(String[] args) {
        int exitCode = new CommandLine(new FileTool()).execute(args);
        System.exit(exitCode);
    }
}

@Command(name = "read", description = "读取文件内容")
class FileReadCommand implements Callable<Integer> {
    @Option(names = {"-p", "--path"}, description = "文件路径", required = true)
    private String filePath;

    @Override
    public Integer call() throws Exception {
        String content = new String(Files.readAllBytes(Paths.get(filePath)));
        System.out.println("文件内容:\n" + content);
        return 0;
    }
}

@Command(name = "count", description = "统计文件行数")
class FileCountCommand implements Callable<Integer> {
    @Option(names = {"-p", "--path"}, description = "文件路径", required = true)
    private String filePath;

    @Override
    public Integer call() throws Exception {
        long lineCount = Files.lines(Paths.get(filePath)).count();
        System.out.println("文件行数: " + lineCount);
        return 0;
    }
}

java -jar filetool.jar --help

java -jar filetool.jar read -p sample.txt

java -jar filetool.jar count -p sample.txt