Java Apache Commons CLI

commons-cli是一个解析命令行输入的工具包。

能够让我们的Java程序实现类似如下的效果：

[root@upupfeng ~]# ls --help

Usage: ls [OPTION]... [FILE]...
  -a, --all                  do not ignore entries starting with .
  -A, --almost-all           do not list implied . and ..
      --author               with -l, print the author of each file
  -b, --escape               print C-style escapes for nongraphic characters
      --block-size=SIZE      scale sizes by SIZE before printing them; e.g.,

支持通过- 参数名=..来传参、支持-h提示等。

实现流程

1. 在程序中设定命令行参数

2. 解析输入参数

3. 使用输入参数

简单代码实现

pom.xml

<dependency>
    <groupId>commons-cli</groupId>
    <artifactId>commons-cli</artifactId>
    <version>1.4</version>
</dependency>

demo

public class CommonCliTest {
    private static Options options = new Options();

    public static void main(String[] args) throws Exception {
        initCliArgs(args);
    }

    private static void initCliArgs(String[] args) throws Exception {
        CommandLineParser parse = new PosixParser();
        options.addOption("d", true, "the dir of file is required");
        options.addOption("h", "help", false, "see usage");

        CommandLine commandLine = null;
        commandLine = parse.parse(options, args, false);

        if (!commandLine.hasOption("d")) {
            HelpFormatter helpFormatter = new HelpFormatter();
            helpFormatter.printHelp("-d is required, please follow the below usage", options);
            System.exit(0);
        }

        String dir = commandLine.getOptionValue("d");
        System.out.println(dir);
    }

}

说明：通过-d传入参数，如果-d没指定，则输出提示。

参考

https://www.jianshu.com/p/c3ae61787a42

https://developer.ibm.com/zh/articles/j-lo-commonscli/

http://commons.apache.org/proper/commons-cli/