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Java Java Objects (Retired) Delivering the MVP Wrapping up

Finally, uncomment the addPost method in Forum.java. Then for the last task, uncomment the main method in Example.java

what i have to do here ??

Finally, uncomment the addPost method in Forum.java. Then for the last task, uncomment the main method in Example.java fixing the bugs as you go to use the new working code. For the forum post title and description, use that to shout out about how it feels to complete this challenge.

PS. You're amazing.

ForumPost.java
public class ForumPost {
  private User mAuthor;
  private String mTitle;
  private String mDescription;

  public ForumPost(User author, String title, String description) {
    mAuthor = author;
    mTitle = title;
    mDescription = description;
  }
  public User getAuthor() {
    return mAuthor;
  }

  public String getTitle() {
    return mTitle;
  }
    public String getDescription() {
      return mDescription;
    }
  // TODO: We need to expose the description
}
User.java
public class User {
  private String mFirstName;
  private String mLastName;

  public User(String firstName, String lastName) {
    // TODO:  Set the private fields here
    mFirstName = firstName;
    mLastName = lastName;
  }
  public String getFirstName() {
  return mFirstName;
  }
  public String getLastName() {
  return mLastName;
  }
}
Forum.java
public class Forum {
  private String mTopic;

  public  Forum(String topic) {
  mTopic = topic;
  }


  public String getTopic() {
      return mTopic;
  }

  public void addPost(ForumPost post) {

      System.out.printf("New post from %s %s about %s.\n",
                         post.getAuthor().getFirstName(),
                         post.getAuthor().getLastName(),
                         post.getTitle());

  }
}
Example.java
public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
    }
     Forum forum = new Forum("Java");
    Take the first two elements passed args
     User author = new User(args[0], args[1]);
    Add the author, title and description
    ForumPost post = new ForumPost();
     forum.addPost(post);
  }
}

1 Answer

Ahmed, you are very close to passing this code challenge! It seems that when you instantiated a new forum post in Example.java that you forgot the arguments that are required from the ForumPost constructor. The ForumPost constructer takes a author, title and description to set up a new forum post. An author has already been instantiated for use in the new forum post and the title and description are anything that you would like. Here is what the correct Example.java code should look like:

Example.java
public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
    }
    Forum forum = new Forum("Java");

    //Take the first two elements passed args
    User author = new User(args[0], args[1]);

    //Add the author, title and description
    ForumPost post = new ForumPost(author, "This is your forum post title", "This is your forum post description.");
    forum.addPost(post);
  }
}

If you have any questions, feel free to ask!

Thanks a lot

Hi Landon

i have a question: how do we know when to use this method below?

User author = new User(args[0], args[1]);

Natenda Manyau I think it's because it says to take the first two elements passed args, which are args[0] and args[1]

i get an exception error java.lang.NullPointerException (Look around Forum.java line 11)