Challenge #187 [Easy] A Flagon of Flags

ChallengeRunner.java

package com.christianwilkie.rdailyprogrammer.c187p1.easy;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

/**
 * Created by chris on 11/8/2014.
 */
public class ChallengeRunner {
    public static void main(String[] args) {
        CommandLineArgumentParser commandLineArgumentParser = new CommandLineArgumentParser();
        Scanner sc = new Scanner(System.in);
        //get number of short form definitions
        int numShortFormDefinitions = 0;
        try {
            numShortFormDefinitions = Integer.parseInt(sc.nextLine());
        } catch(NumberFormatException e) {
            e.printStackTrace();
        }
        List<String> rawShortFormDefinitions = new ArrayList<>(numShortFormDefinitions);
        //add short form definitions
        for(int i = 0; i < numShortFormDefinitions; i++) {
            rawShortFormDefinitions.add(sc.nextLine());
        }
        //get raw argument line data
        String rawArgumentLine = sc.nextLine();
        //input done, now parse
        List<String> output = commandLineArgumentParser.parseCommandLineArguments(rawShortFormDefinitions,rawArgumentLine);
        //print the output
        output.forEach(System.out::println);
    }
}

CommandLineArgumentParser.java

package com.christianwilkie.rdailyprogrammer.c187p1.easy;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Created by chris on 11/8/2014.
 */
public class CommandLineArgumentParser {
    private Map<String, String> shortFormDefinitionMap;
    private boolean errorFlag = false;
    private static String errorOutputString = "Internal error in argument parsing.";

    public CommandLineArgumentParser() {
        shortFormDefinitionMap = new HashMap<>();
    }

    public List<String> parseCommandLineArguments(List<String> rawShortFormDefinitions, String rawArgumentLine) {
        List<String> output;
        //parse all short form definitions
        rawShortFormDefinitions.forEach(this::parseShortFormDefinition);
        //parse the argument lines and form the output
        output = parseRawArgumentLine(rawArgumentLine);
        //if there was an error at some point, return bad output info
        if (errorFlag == true) {
            List<String> badOutput = new ArrayList<>(1);
            badOutput.add(errorOutputString);
            return badOutput;
        }
        //no errors, return good info
        return output;
    }

    private void parseShortFormDefinition(String shortFormDefinition) {
        String[] splitShortFormDefinition = shortFormDefinition.split(":");
        if(splitShortFormDefinition.length != 2) {
            errorFlag = true;
        } else {
            shortFormDefinitionMap.put(splitShortFormDefinition[0],splitShortFormDefinition[1]);
        }
    }

    private List<String> parseRawArgumentLine(String rawArgumentLine) {
        List<String> output = new ArrayList<>();
        String[] splitArguments = rawArgumentLine.split(" ");
        for(String rawArgument: splitArguments) {
            //add each parsed argument to the output
            parseCommandLineArgument(rawArgument).forEach(output::add);
        }
        return output;
    }

    private List<String> parseCommandLineArgument(String rawArgument) {
        List<String> parsedArguments = new ArrayList<>();
        if(rawArgument.startsWith("--")) {
            //full argument
            parsedArguments.add("flag: " + rawArgument);
        } else if (rawArgument.startsWith("-")) {
            //condensed argument
            //split up into chars in case there is more than 1 argument, also skip the '-'
            char[] argumentChars = rawArgument.substring(1).toCharArray();
            for(char argument: argumentChars) {
                //check for definition
                String fullDefinition = shortFormDefinitionMap.get(String.valueOf(argument));
                if (fullDefinition == null) {
                    errorFlag = true;
                    parsedArguments.add("");
                } else {
                    parsedArguments.add("flag: " + fullDefinition);
                }
            }
        } else {
            //parameter
            parsedArguments.add("parameter: " + rawArgument);
        }
        return parsedArguments;
    }
}