CommandLine.java

package util;

import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CommandLine extends Option {
  private static Pattern optionPattern = Pattern.compile("\\[-(\\w+)((?: \\w+)*)\\]");
  private Map<String, Option> possibleOptions = new ConcurrentHashMap<String, Option>();

  public CommandLine(String optionDescriptor) {
    int optionEndIndex = 0;
    Matcher matcher = optionPattern.matcher(optionDescriptor);
    while (matcher.find()) {
      Option option = new Option();
      option.parseArgumentDescriptor(matcher.group(2));
      possibleOptions.put(matcher.group(1), option);
      optionEndIndex = matcher.end();
    }

    String remainder = optionDescriptor.substring(optionEndIndex);
    parseArgumentDescriptor(remainder);
  }

  public boolean parse(String[] args) {
    boolean successfulParse = true;
    Option currentOption = this;
    for (int i = 0; successfulParse && i < args.length; i++) {
      String arg = args[i];

      if (currentOption != this && !currentOption.needsMoreArguments())
        currentOption = this;

      if (arg.startsWith("-")) {
        if (currentOption.needsMoreArguments() && currentOption != this)
          successfulParse = false;
        else {
          String argName = arg.substring(1);
          currentOption = possibleOptions.get(argName);
          if (currentOption != null)
            currentOption.active = true;
          else
            successfulParse = false;
        }
      } else if (currentOption.needsMoreArguments())
        currentOption.addArgument(arg);
      else // too many args
        successfulParse = false;
    }
    if (successfulParse && currentOption.needsMoreArguments())
      successfulParse = false;
    return successfulParse;
  }

  public boolean hasOption(String optionName) {
    Option option = possibleOptions.get(optionName);
    if (option == null)
      return false;

    return option.active;
  }

  public String getOptionArgument(String optionName, String argName) {
    Option option = possibleOptions.get(optionName);
    if (option == null)
      return null;
    else
      return option.getArgument(argName);
  }
}

class Option {
  public boolean active = false;
  protected String[] argumentNames;
  protected String[] argumentValues;
  protected int argumentIndex = 0;

  protected void parseArgumentDescriptor(String arguments) {
    String[] tokens = split(arguments);
    argumentNames = tokens;
    argumentValues = new String[argumentNames.length];
  }

  public String getArgument(String argName) {
    for (int i = 0; i < argumentNames.length; i++) {
      String requiredArgumentName = argumentNames[i];
      if (requiredArgumentName.equals(argName))
        return argumentValues[i];
    }
    return null;
  }

  public boolean needsMoreArguments() {
    return argumentIndex < argumentNames.length;
  }

  public void addArgument(String value) {
    argumentValues[argumentIndex++] = value;
  }

  protected String[] split(String value) {
    String[] tokens = value.split(" ");
    List<String> usableTokens = new LinkedList<String>();
    for (int i = 0; i < tokens.length; i++) {
      String token = tokens[i];
      if (token.length() > 0)
        usableTokens.add(token);
    }
    return usableTokens.toArray(new String[]{});
  }
}