// Abstract Products
public interface Letter {
  public String getIntro();
  public String getBody();
}

public interface Resume {
  public String getIntro();
  public String getBody();
}

// Concrete Products for Resume
public class FancyResume implements Resume {
  public void getIntro() {
    // Get fancy intro here
  }
  public void getBody() {
    // Get fancy body here
  }
}

public class ModernResume implements Resume {
  public void getIntro() {
    // Get modern intro here
  }
  public void getBody() {
    // Get modern body here
  }
}

// Concrete Products for Letter
public class FancyLetter implements Letter {
  public void getIntro() {
    // Get fancy intro here
  }
  public void getBody() {
    // Get fancy body here
  }
}

public class ModernLetter implements Letter {
  public void getIntro() {
    // Get modern intro here
  }
  public void getBody() {
    // Get modern body here
  }
}

// Abstract Factory
public interface DocumentCreator {
  public Letter createLetter();
  public Resume cerateResume();
}

// Concrete Factory 1
public class FancyDocumentCreator implements DocumentCreator {
  // Create fancy documents
  public Letter createLetter() {
    return new FancyLetter();
  }
  public Resume createResume() {
    return new Resume();
  }
}

// Concrete Factory 2
public class ModernDocumentCreator implements DocumentCreator {
  // Create modern documents
  public Letter createLetter() {
    return new ModernLetter();
  }
  public Resume createResume() {
    return new ModernResume();
  }
}

// Client class
public class DocumentBuilder {
  public void buildResume(DocumentCreator documentCreator) {
    Resume resume = documentCreator.createResume();
    // do stuff here presumably
  }
  public void buildLetter(DocumentCreator documentCreator) {
    Letter letter = documentCreator.createLetter();
  }
}

// Mechanism to build new documents
public class Main {
  public static void main(String[] args) {
    // Assume first argument is fancy/modern and second is resume/letter
    DocumentBuilder builder = new DocumentBuilder();
    DocumentCreator docCreator = null;

    // Specify fancy or modern based on first input
    if (args[0].equals("fancy")) {
      docCreator = new FancyDocumentCreator();
    }
    else if (args[0].equals("modern")) {
      docCreator = new ModernDocumentCreator();
    }
    else {
      throw new RuntimeException("Make your mind up - fancy or modern?");
    }

    // Specify letter or resume based on second input
    if (args[1].equals("resume")) {
      docCreator.createResume();
    }
    else if (args[1].equals("letter")) {
      docCreator.createLetter();
    }
    else {
      throw new RuntimeException("Make your mind up - letter or resume?");
    }
  }
}