Class RunFirst

src/main/java/picocli/CommandLine.java:2337–2384

Command line plain IExecutionStrategy execution strategy that prints help if requested, and otherwise executes the top-level Runnable or Callable command. For use by the #execute(String...) execute method. @since 2.0

     * For use by the {@link #execute(String...) execute} method.
     * @since 2.0 */
    public static class RunFirst extends AbstractParseResultHandler<List<Object>> implements IParseResultHandler {
        /** {@inheritDoc} */
        public int execute(ParseResult parseResult) throws ExecutionException { return super.execute(parseResult); }

        /** Prints help if requested, and otherwise executes the top-level {@code Runnable} or {@code Callable} command.
         * Finally, either a list of result objects is returned, or the JVM is terminated if an exit code {@linkplain #andExit(int) was set}.
         * If the top-level command does not implement either {@code Runnable} or {@code Callable}, an {@code ExecutionException}
         * is thrown detailing the problem and capturing the offending {@code CommandLine} object.
         *
         * @param parsedCommands the {@code CommandLine} objects that resulted from successfully parsing the command line arguments
         * @param out the {@code PrintStream} to print help to if requested
         * @param ansi for printing help messages using ANSI styles and colors
         * @return an empty list if help was requested, or a list containing a single element: the result of calling the
         *      {@code Callable}, or a {@code null} element if the top-level command was a {@code Runnable}
         * @throws ParameterException if the {@link HelpCommand HelpCommand} was invoked for an unknown subcommand. Any {@code ParameterExceptions}
         *      thrown from this method are treated as if this exception was thrown during parsing and passed to the {@link IExceptionHandler}
         * @throws ExecutionException if a problem occurred while processing the parse results; use
         *      {@link ExecutionException#getCommandLine()} to get the command or subcommand where processing failed
         */
        public List<Object> handleParseResult(List<CommandLine> parsedCommands, PrintStream out, Help.Ansi ansi) {
            if (printHelpIfRequested(parsedCommands, out, err(), ansi)) { return returnResultOrExit(Collections.emptyList()); }
            return returnResultOrExit(executeUserObject(parsedCommands.get(0), new ArrayList<Object>()));
        }
        /** Executes the top-level {@code Runnable} or {@code Callable} subcommand.
         * If the top-level command does not implement either {@code Runnable} or {@code Callable} and is not a {@code Method}, an {@code ExecutionException}
         * is thrown detailing the problem and capturing the offending {@code CommandLine} object.
         *
         * @param parseResult the {@code ParseResult} that resulted from successfully parsing the command line arguments
         * @return an empty list if help was requested, or a list containing a single element: the result of calling the
         *      {@code Callable}, or a {@code null} element if the last (sub)command was a {@code Runnable}
         * @throws ExecutionException if a problem occurred while processing the parse results; use
         *      {@link ExecutionException#getCommandLine()} to get the command or subcommand where processing failed
         * @since 3.0 */
        protected List<Object> handle(ParseResult parseResult) throws ExecutionException {
            Tracer t = CommandLine.tracer();
            t.debug("RunFirst: executing user object for '%s'...", parseResult.commandSpec().qualifiedName());
            return executeUserObject(parseResult.commandSpec().commandLine(), new ArrayList<Object>()); // first
        }

        protected List<IExitCodeGenerator> extractExitCodeGenerators(ParseResult parseResult) {
            if (parseResult.commandSpec().userObject() instanceof IExitCodeGenerator) {
                return Collections.singletonList((IExitCodeGenerator) parseResult.commandSpec().userObject());
            }
            return Collections.emptyList();
        }

        @Override protected RunFirst self() { return this; }
    }
    /**
     * Command line {@linkplain IExecutionStrategy execution strategy} that prints help if requested, and otherwise executes the most specific
     * {@code Runnable} or {@code Callable} subcommand.