OptionHandler Class — spring-boot Architecture

Source Code

cli/spring-boot-cli/src/main/java/org/springframework/boot/cli/command/options/OptionHandler.java lines 52–204

public class OptionHandler {

	private final Function<String, String> argumentProcessor;

	private @Nullable OptionParser parser;

	private @Nullable String help;

	private @Nullable Collection<OptionHelp> optionHelp;

	/**
	 * Create a new {@link OptionHandler} instance.
	 */
	public OptionHandler() {
		this(Function.identity());
	}

	/**
	 * Create a new {@link OptionHandler} instance with an argument processor.
	 * @param argumentProcessor strategy that can be used to manipulate arguments before
	 * they are used.
	 */
	public OptionHandler(Function<String, String> argumentProcessor) {
		this.argumentProcessor = argumentProcessor;
	}

	public OptionSpecBuilder option(String name, String description) {
		return getParser().accepts(name, description);
	}

	public OptionSpecBuilder option(List<String> aliases, String description) {
		return getParser().acceptsAll(aliases, description);
	}

	public OptionParser getParser() {
		if (this.parser == null) {
			this.parser = new OptionParser();
			options();
		}
		return this.parser;
	}

	protected void options() {
	}

	public final ExitStatus run(String... args) throws Exception {
		String[] argsToUse = args.clone();
		for (int i = 0; i < argsToUse.length; i++) {
			if ("-cp".equals(argsToUse[i])) {
				argsToUse[i] = "--cp";
			}
			argsToUse[i] = this.argumentProcessor.apply(argsToUse[i]);
		}
		OptionSet options = getParser().parse(argsToUse);
		return run(options);
	}

	/**
	 * Run the command using the specified parsed {@link OptionSet}.
	 * @param options the parsed option set
	 * @return an ExitStatus
	 * @throws Exception in case of errors
	 */
	protected ExitStatus run(OptionSet options) throws Exception {
		return ExitStatus.OK;
	}

	public String getHelp() {
		if (this.help == null) {
			getParser().formatHelpWith(new BuiltinHelpFormatter(80, 2));
			OutputStream out = new ByteArrayOutputStream();
			try {
				getParser().printHelpOn(out);
			}
			catch (IOException ex) {
				return "Help not available";
			}
			this.help = out.toString().replace(" --cp ", " -cp  ");
		}
		return this.help;
	}

	public Collection<OptionHelp> getOptionsHelp() {
		if (this.optionHelp == null) {
			OptionHelpFormatter formatter = new OptionHelpFormatter();
			getParser().formatHelpWith(formatter);
			try {
				getParser().printHelpOn(new ByteArrayOutputStream());
			}
			catch (Exception ex) {
				// Ignore and provide no hints
			}
			this.optionHelp = formatter.getOptionHelp();
		}
		return this.optionHelp;
	}

	private static final class OptionHelpFormatter implements HelpFormatter {

		private final List<OptionHelp> help = new ArrayList<>();

		@Override
		public String format(Map<String, ? extends OptionDescriptor> options) {
			Comparator<OptionDescriptor> comparator = Comparator
				.comparing((optionDescriptor) -> optionDescriptor.options().iterator().next());
			Set<OptionDescriptor> sorted = new TreeSet<>(comparator);
			sorted.addAll(options.values());
			for (OptionDescriptor descriptor : sorted) {
				if (!descriptor.representsNonOptions()) {
					this.help.add(new OptionHelpAdapter(descriptor));
				}
			}
			return "";
		}

		Collection<OptionHelp> getOptionHelp() {
			return Collections.unmodifiableList(this.help);
		}

	}

	private static class OptionHelpAdapter implements OptionHelp {

		private final Set<String> options;

		private final String description;

		OptionHelpAdapter(OptionDescriptor descriptor) {
			this.options = new LinkedHashSet<>();
			for (String option : descriptor.options()) {
				String prefix = (option.length() != 1) ? "--" : "-";
				this.options.add(prefix + option);
			}
			if (this.options.contains("--cp")) {
				this.options.remove("--cp");
				this.options.add("-cp");
			}
			this.description = descriptor.description();
		}

		@Override
		public Set<String> getOptions() {
			return this.options;
		}

		@Override
		public String getUsageHelp() {
			return this.description;
		}

	}

}