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Java Java Data Structures Exploring the Java Collection Framework ArrayLists

Posted by Dan Brown
Dan Brown
11,630 Points

I'm not sure what's wrong?!?!

Question: "Let's add a method that returns a list of all links in the body of the document. All words that start with http should be considered links. Name it getExternalLinks."

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

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
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> results = new ArrayList<String>();
    for(String word : getWords()) {
      if (word.startsWith("http")) {
        results.add(word);
      }
    }
    return results;
  }

  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;
  }
}

1 Answer

Simon Coates
Simon Coates
28,694 Points
Simon Coates
Simon Coates
28,694 Points

Try adding:

import java.util.List;

You can usually get a pretty good idea of what the problem is provided you can read error messages. However, an IDE would probably just tell you the solution.

Dan Brown
Dan Brown
11,630 Points

That was it! Thank you!