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 Data Structures Exploring the Java Collection Framework Sets

luis martinez
luis martinez
2,480 Points
Posted by luis martinez
luis martinez
2,480 Points

I give up. I tried everything but i keep getting errors

package com.example;

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


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;
  }

  public Set<String> getAllAuthors() { //having a problem here
    Set<String> allAuthors = new TreeSet<String>(); 
    for (BlogPost post : getPosts()) {
     allAuthors.addAll(post.getAuthor()); 
    }
    return AllAuthors;
  }
}
Kevin Faust
Kevin Faust
15,353 Points
Kevin Faust
Kevin Faust
15,353 Points

//Edited for markup

1 Answer

Kevin Faust
Kevin Faust
15,353 Points
Kevin Faust
Kevin Faust
15,353 Points

First off, you put the required method in the wrong class. You should be working on the Blog.java tab.

Secondly, it's not addAll() but rather just add(). We're only getting a single string per loop. Only one thing to add means just add()

And lastly, you spelled the name of your Set incorrectly on your return statement

Take a look below,

public Set<String> getAllAuthors() {  //<<<<<<<<<<<< make sure this is in the Blog.java tab
    Set<String> allAuthors = new TreeSet<String>(); 
    for (BlogPost post : getPosts()) {
     allAuthors.add(post.getAuthor());  // <<<<<<<<<<<< .add()
    }
    return allAuthors; //<<<<<<<<< incorrectly spelled before
  }

Let me know if that fixed it

luis martinez
luis martinez
2,480 Points
luis martinez
luis martinez
2,480 Points

Thank you very much. I feel dumb for nothing putting it in the Blog.java