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

After you uncomment the code in Main.java and Forum.java, fix the code as described in the comments of Main.java.

After you uncomment the code in Main.java and Forum.java, fix the code as described in the comments of Main.java. The code in main is attempting to use the code you just fixed.

what is it i'm doing wrong there??

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

  // TODO: add a constructor that accepts a topic and sets the private field 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", 
            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
            this.firstName = firstName;
            this.lastName = 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;

  public ForumPost (User author, String title, String description) {
    this.author = author;
    this.title = title;
    this.description = description; }
    // TODO: add a constructor that accepts the author, title and 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]); // Add args[0] and args[1] those are the first arguments presented which translate to firstName and lastName variables.
    ForumPost post = new ForumPost( author, "title", "description"); // Look at ForumPost.java it is looking for an author, title, and discription so put
// author, "title", and "description" inside of ForumPost(""HERE"") 
    forum.addPost(post);

// *
  }
}

1 Answer

Steven Parker
Steven Parker
231,172 Points

This one was a bit tricky to find, since the issues occurred in task 1, but the validation did not catch them until task 4!

When adding the new constructor for "Forum" in task 1, the code was not placed beneath the comment but above it. While this would not cause a problem itself, adding the new code accidentally replaced a line that was originally provided above the comment which declared the field "topic". That line needs to remain in the code.

The other issue is that the access of the new constructor was set to "private" instead of "public".

Fix those up and you're good to go!