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Java Java Objects Delivering the MVP Forum

Gonzalo Torres del Fierro
PLUS
Gonzalo Torres del Fierro
Courses Plus Student 16,750 Points

i need help i get lost here...

i know i´m close, but i get lost..

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
    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;

  // TODO: add a constructor that accepts the author, title and description
   public ForumPost(User Author, String title, String description){
    this.author = userAuthor;
    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");
    // TODO: pass in the first name and last name that are in the args parameter
    User author = new User("Gonzalo","Torres");
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(something here!!!,"nuevo","rumbo");
    forum.addPost(post);


  }

}

2 Answers

Chris Jones
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Chris Jones
Java Web Development Techdegree Graduate 23,921 Points

Are you getting an error on this line?

ForumPost post = new ForumPost(something here!!!,"nuevo","rumbo");

If so, it looks like the ForumPost constructor takes a User object in the parameter that currently has "something here!!!". Change "something here!!!" to the User object you just created called author and that should help.

I don't know if it will solve everything, but it's the first thing I came across.

I hope that helps!

Gonzalo Torres del Fierro
PLUS
Gonzalo Torres del Fierro
Courses Plus Student 16,750 Points

thx Chris, the problem , is i try several approaches, and i think i need some help, i would like to know how to call properly the "author" having on mind that author, has his own way, because it is a "User" type, and go throw and from another class.... if you can share your solution would be nice...and thx again

Chris Jones
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Chris Jones
Java Web Development Techdegree Graduate 23,921 Points

Not a problem! After looking at the code challenge, you'll also need to pass the main method's parameters into the construction of the author variable, which is a User object. The User constructor takes two parameters, firstName and lastName, and you are to assume that these are passed to the String[] args variable in the main method.

I apologize if that was a little confusing, so here is the code. Let me know if you have any more questions!

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;
  }


  //Uncomment this when you are prompted to do so
  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
    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;

  // TODO: add a constructor that accepts the author, title and 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);
    }
    //Uncomment this when prompted
    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[0], args[1]);
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(author, "A Title", "A Description");
    forum.addPost(post);

// */
  }

}