Sets challenge

Question

I get an error saying something else needs to be imported.

com/example/BlogPost.java

package com.example;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;


public class BlogPost implements Comparable<BlogPost>, Serializable {
  private String mAuthor;
  private String mTitle;
  private String mBody;
  private String mCategory;
  private Date mCreationDate;

  public BlogPost(String author, String title, String body, String category, Date creationDate) {
    mAuthor = author;
    mTitle = title;
    mBody = body;
    mCategory = category;
    mCreationDate = creationDate;
  }

  public int compareTo(BlogPost other) {
    if (equals(other)) {
      return 0;
    }
    return mCreationDate.compareTo(other.mCreationDate);
  }

  public String[] getWords() {
    return mBody.split("\\s+");
  }

  public List<String> getExternalLinks() {
    List<String> links = new ArrayList<String>();
    for (String word : getWords()) {
      if (word.startsWith("http")) {
        links.add(word);
      }
    }
    return links;
  }

  public String getAuthor() {
    return mAuthor;
  }

  public String getTitle() {
    return mTitle;
  }

  public String getBody() {
    return mBody;
  }

  public String getCategory() {
    return mCategory;
  }

  public Date getCreationDate() {
    return mCreationDate;
  }
}

com/example/Blog.java

package com.example;

import com.example.BlogPost;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;

public class Blog {
  List<BlogPost> mPosts;

  public Blog(List<BlogPost> posts) {
    mPosts = posts;
  }

  public List<BlogPost> getPosts() {
    return mPosts;
  }
  public getAllAuthors(){
  Set<String> authors=new TreeSet<String>();
  authors.add(BlogPost.getAuthor());
  return authors;

  }
}

Answer 1 · 2019-01-14T11:59:22Z

January 14, 2019 11:59am

Hello Leo,

You're close to passing this one. Here are the issues I've found.

The first issue I noticed is that your getAllAuthors method is missing a return type. The challenge asks that you return a java.util.Set of all the authors. So first step is to add the return type like this.

public Set<String> getAllAuthors() 
{
...
}

Next, when adding authors to the set, you're trying to access the getAuthor method from the BlogPost class instead of looping through mPosts to get the blog post objects. The challenge asks that we loop over all the blog posts so that we can call getAuthor to return all of the authors. That would look something like this.

for (BlogPost post : mPosts) 
{
    authors.add(post.getAuthor());
}

I hope this helps. Please let me know if you have any other related questions. Happy coding 🙂

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Leo Marco Corpuz

Leo Marco Corpuz

Sets challenge

1 Answer

Justin Horner

Justin Horner

Leo Marco Corpuz

Leo Marco Corpuz

Justin Horner

Justin Horner