Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Objects Delivering the MVP Forum

Gabrielle Harris
Gabrielle Harris
13,135 Points
Posted by Gabrielle Harris
Gabrielle Harris
13,135 Points

I'm not sure what I'm doing wrong and I can't move forward

I tried User and author and it's late and I can't seem to get this right.

Thanks in advance.

Forum.java 
public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic
  public Forum(String topic) {
   this.topic = topic;
  }

  public String getTopic() {
    return topic;
  }



  public void addPost(ForumPost post) {
    System.out.printf("A new post in %s topic from %s %s about %s is available",
            topic,
            post.getAuthor().getFirstName(),
            post.getAuthor().getLastName(),
            post.getTitle()
    );
  }
  */

}
User.java 
public class User {
  // TODO: add private fields for firstName and lastName
private String firstName;
  private String lastName;


  public User(String firstName, String lastName) {
    // TODO: set and add the private fields
firstName = "";
    lastName = "";

  }

  // TODO: add getters for firstName and lastName
public String getFirstName() {
  return firstName;
}

 public String getLastName() {
   return lastName;
 }
}
ForumPost.java 
public class ForumPost {
  private User author;
  private String title;
  private String description;

  // TODO: add a constructor that accepts the author, title and description
  public ForumPost(User author, String title, String description) {
    author = "";
    title = "";
    description = "";
  }

  public User getAuthor() {
    return author;
  }

  public String getTitle() {
    return title;
  }

  public String getDescription() {
    return description;
  }
}
Main.java 
public class Main {

  public static void main(String[] args) {
    System.out.println("Beginning forum example");
    if (args.length < 2) {
      System.out.println("Usage: java Main <first name> <last name>");
      System.err.println("<first name> and <last name> are required");
      System.exit(1);
    }

    Forum forum = new Forum("Java");

    // TODO: pass in the first name and last name that are in the args parameter
    User author = new User(args[2]);
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(User, "Title", "Description");
    forum.addPost(post);

// */
  }

}

1 Answer

Dave Harker
PLUS
Dave Harker
Courses Plus Student 15,510 Points
Dave Harker
Dave Harker
Courses Plus Student 15,510 Points

Hi Gabrielle,

Looks like you're not initialising the private variables with the arguments passed in for several of the files. Also, when initialising a new User in main you'll need both String[] args (firstname and lastname) ... so args[0], args[1] ... mine looks like this:

Forum.java

public class Forum {
  private String topic;

  public Forum(String topic) {
    this.topic = topic;
  }

  public String getTopic() {
    return topic;
  }

  public void addPost(ForumPost post) {
    System.out.printf("A new post in %s topic from %s %s about %s is available",
            topic,
            post.getAuthor().getFirstName(),
            post.getAuthor().getLastName(),
            post.getTitle()
    );
  }
}

User.java

public class User {
  private String firstName;
  private String lastName;

  public User(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
  }

  public String getFirstName() {
    return this.firstName;
  }

  public String getLastName() {
    return this.lastName;
  }
}

ForumPost.java

public class ForumPost {
  private User author;
  private String title;
  private String description;

  public ForumPost(User author, String title, String description) {
    this.author = author;
    this.title = title;
    this.description = description;
  }

  public User getAuthor() {
    return author;
  }

  public String getTitle() {
    return title;
  }

  public String getDescription() {
    return description;
  }
}

Main.java

public class Main {

  public static void main(String[] args) {
    System.out.println("Beginning forum example");
    if (args.length < 2) {
      System.out.println("Usage: java Main <first name> <last name>");
      System.err.println("<first name> and <last name> are required");
      System.exit(1);
    }

    Forum forum = new Forum("Java");
    User author = new User(args[0], args[1]);
    ForumPost post = new ForumPost(author, "title", "description");
    forum.addPost(post);
  }
}

Hope that helps, and happy coding.

Dave.

Gabrielle Harris
Gabrielle Harris
13,135 Points
Gabrielle Harris
Gabrielle Harris
13,135 Points

Thank you so much for your help!