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Java Java Objects Delivering the MVP Forum

Posted by Elias Svoba
Elias Svoba
14,347 Points

Help with wrapping up

./ForumPost.java:13: error: incompatible types: User cannot be converted to String return author; ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error

i keep getting this message i'm stuck where am i making a mistake?

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) {
    // TODO:  Set the private fields here
    this.firstName = firstName;
    this.lastName = 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;
  }

  public String 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);
    }

    User author = new User(args[0], args[1]);
    ForumPost post = new ForumPost(author, "Title", "Description");
  }
}

1 Answer

Yanuar Prakoso
Yanuar Prakoso
15,196 Points
Yanuar Prakoso
Yanuar Prakoso
15,196 Points

Hi Elias...

You have some missing lines of code in your Main Java. Those missing lines are important parts of the whole program that make sure the Forum class will be instantiated and runs. The last lines of your Main.java should be look like this:

 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, "Title", "Description");
    forum.addPost(post);

I hope this can help

Elias Svoba
Elias Svoba
14,347 Points

Thanks Yanuar.