java - 将参数解析到 Java 命令行程序

Question

如果我想解析这个怎么办:

java MyProgram -r opt1 -S opt2 arg1 arg2 arg3 arg4 --test -A opt3

而我在程序中想要的结果是:

regular Java args[]  of size=4
org.apache.commons.cli.Options[]  of size=3
org.apache.commons.cli.Options[] #2 of size=1

我更喜欢使用 Apache Commons CLI ，但文档对我上面介绍的案例有点不清楚。具体来说，文档没有告诉您如何处理我在下面指定的第三种类型的选项:

1. options with a "-" char
2. options with a "--" char
3. options without any marker, or "bare args"

我希望 Apache Commons CLI 能够工作，但如果这些 args 没有选项前缀，仍然能够将常规 args 传递给程序。也许确实如此，但当我阅读它时，文档并没有这样说......

Answer 1

使用 Apache Commons CLI library commandline.getArgs() 获取 arg1、arg2、arg3 和 arg4。这是一些代码:

    import org.apache.commons.cli.CommandLine;
    import org.apache.commons.cli.Option;
    import org.apache.commons.cli.Options;
    import org.apache.commons.cli.Option.Builder;
    import org.apache.commons.cli.CommandLineParser;
    import org.apache.commons.cli.DefaultParser;
    import org.apache.commons.cli.ParseException;

    public static void main(String[] parameters)
    {
        CommandLine commandLine;
        Option option_A = Option.builder("A")
            .required(true)
            .desc("The A option")
            .longOpt("opt3")
            .build();
        Option option_r = Option.builder("r")
            .required(true)
            .desc("The r option")
            .longOpt("opt1")
            .build();
        Option option_S = Option.builder("S")
            .required(true)
            .desc("The S option")
            .longOpt("opt2")
            .build();
        Option option_test = Option.builder()
            .required(true)
            .desc("The test option")
            .longOpt("test")
            .build();
        Options options = new Options();
        CommandLineParser parser = new DefaultParser();

        String[] testArgs =
        { "-r", "opt1", "-S", "opt2", "arg1", "arg2",
          "arg3", "arg4", "--test", "-A", "opt3", };

        options.addOption(option_A);
        options.addOption(option_r);
        options.addOption(option_S);
        options.addOption(option_test);

        try
        {
            commandLine = parser.parse(options, testArgs);

            if (commandLine.hasOption("A"))
            {
                System.out.print("Option A is present.  The value is: ");
                System.out.println(commandLine.getOptionValue("A"));
            }

            if (commandLine.hasOption("r"))
            {
                System.out.print("Option r is present.  The value is: ");
                System.out.println(commandLine.getOptionValue("r"));
            }

            if (commandLine.hasOption("S"))
            {
                System.out.print("Option S is present.  The value is: ");
                System.out.println(commandLine.getOptionValue("S"));
            }

            if (commandLine.hasOption("test"))
            {
                System.out.println("Option test is present.  This is a flag option.");
            }

            {
                String[] remainder = commandLine.getArgs();
                System.out.print("Remaining arguments: ");
                for (String argument : remainder)
                {
                    System.out.print(argument);
                    System.out.print(" ");
                }

                System.out.println();
            }

        }
        catch (ParseException exception)
        {
            System.out.print("Parse error: ");
            System.out.println(exception.getMessage());
        }
    }