Java commons-cli，带有可能值列表的选项

command-line-interface command-line java apache-commons apache-commons-cli

2022-09-04 08:26:00

如何使选项仅接受某些指定值，如以下示例所示：

$ java -jar Mumu.jar -a foo
OK
$ java -jar Mumu.jar -a bar
OK
$ java -jar Mumu.jar -a foobar
foobar is not a valid value for -a

答案 1

由于commons-cli不直接支持这一点，最简单的解决方案可能是在获得选项时检查选项的值。

答案 2

另一种方法是扩展 Option 类。在工作中，我们已经做到了：

    public static class ChoiceOption extends Option {
        private final String[] choices;

        public ChoiceOption(
            final String opt,
            final String longOpt,
            final boolean hasArg,
            final String description,
            final String... choices) throws IllegalArgumentException {
        super(opt, longOpt, hasArg, description + ' ' + Arrays.toString(choices));
        this.choices = choices;
       }

      public String getChoiceValue() throws RuntimeException {
        final String value = super.getValue();
        if (value == null) {
            return value;
        }
        if (ArrayUtils.contains(choices, value)) {
            return value;
        }
        throw new RuntimeException( value " + describe(this) + " should be one of " + Arrays.toString(choices));
     }

      @Override
      public boolean equals(final Object o) {
        if (this == o) {
            return true;
        } else if (o == null || getClass() != o.getClass()) {
            return false;
        }
        return new EqualsBuilder().appendSuper(super.equals(o))
                .append(choices, ((ChoiceOption) o).choices)
                .isEquals();
     }

      @Override
      public int hashCode() {
        return new ashCodeBuilder().appendSuper(super.hashCode()).append(choices).toHashCode();
      }
  }