Apache Commons CLI允许参数选项或无参数选项

Question

简单地说，我想知道是否有可能让参数接受一个选项或不接受任何选项。这对于列表很有用。示例：-a将列出可能的选项，而-a stuff将使用这些内容来做事情。

下面是我当前的代码：

options.addOption("f", "look-and-feel", false, "This sets the look and feel.");
//Some stuff happens here
if (cmd.hasOption('f')) {
    String laf = cmd.getOptionValue('f');
    System.out.println(laf);
    if (laf == null) {
        for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
            System.out.println(info.getClassName());
        }
        return;
    } else {
        setLookAndFeel(laf);
    }
} else {
    setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
}

输入-f会列出正确的外观，而指定-f com.laf.LookAndFeel仍然会列出该外观。有什么想法吗？

Answer 1

创建选项时，请改用以下内容：

Option lookAndFeelOption = new Option("f", "look-and-feel", true, "This sets the look and feel.");
lookAndFeelOption.setOptionalArg(true);
options.addOption(lookAndFeelOption);