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Java Java Data Structures Exploring the Java Collection Framework Sets

Steven Morimoto
PLUS
Steven Morimoto
Courses Plus Student 1,836 Points
Posted by Steven Morimoto
Steven Morimoto
Courses Plus Student 1,836 Points

How do I solve the Sets quiz?

I've watched the video several times and the coding makes sense. However, the thing that's confusing me is that it asks you to sort the author's names alphabetically. Since getAuthor() method is in the BlogPost class i would need to create an object to BlogPost and loop through getAuthor...on the other hand, getAuthor() isn't an array so i might be way off. So pretty much, I know to alphabetize author's names I need a TreeSet and to loop through all of the names, but I'm not really sure how loop through the author's names.

I hope that that was enough info ^_^

Thanks,

Steve

com/example/BlogPost.java 
package com.example;

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


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 java.util.HashSet;
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 List<BlogPost> getAllAuthors()
  {
    for(String name : List<BlogPost>.getAuthor())
    {
      Set<String> authors = new TreeSet<String>(name);
    }
    return authors;
  }
}
Rich Zimmerman
Rich Zimmerman
24,063 Points
Rich Zimmerman
Rich Zimmerman
24,063 Points

Double check the description of the code challenge. It's set up so the Blog object is initialized with a list of BlogPosts. So you already have a list full of BlogPost objects to iterate over here:

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