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Java

Posted by Edith England
Edith England
4,270 Points

Java Data Structures Sets Challenge: java.lang.reflect.InvocationTargetException error

Here is my code for the challenge:

I am getting the error "java.lang.reflect.InvoationTargetException error".

Any thoughts?

package com.example;

import java.util.List;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

public class Blog {
  List<BlogPost> mPosts;

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

  public List<BlogPost> getPosts() {
    return mPosts;
  }

   public Set<String> getAllAuthors()
  {
    Set collect = new TreeSet<String>();
     for (String loop: getAllAuthors()){
      collect.add(loop);
     }

      return collect;
}

}

5 Answers

James Simshaw
James Simshaw
28,738 Points

Hello,

I'm not sure immediately if this is causing the exception, but you don't include what your set is comprised of when you declare the set.

Set collect = new TreeSet<String>();

should be

Set<String> collect = new TreeSet<String>();
Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

I think you also want to loop through mPosts and use the getAuthor method on the BlogPost object.

Edith England
Edith England
4,270 Points
Edith England
Edith England
4,270 Points

Thanks both. I should have come back and replied sooner, my apologies. I restarted the challenge and passed. I was more interested in the type of error. I'd encountered it previously in another of the Efficiency challenges, and a brief google search seemed to me to suggest it might be caused by how I was naming my variables or similar.

Many thanks for both replies.

Edith England
Edith England
4,270 Points
Edith England
Edith England
4,270 Points

Thanks both. I should have come back and replied sooner, my apologies. I restarted the challenge and passed. I was more interested in the type of error. I'd encountered it previously in another of the Efficiency challenges, and a brief google search seemed to me to suggest it might be caused by how I was naming my variables or similar.

Many thanks for both replies.

Edith England
Edith England
4,270 Points
Edith England
Edith England
4,270 Points

Just to add. I finished the Data Structure Sets course last night. I've left feedback in the relevant places but wanted to say again what an awesome course it is. I found it very challenging, and that it really stretched me, but while being enjoyable and intriguing enough that I wanted to finish the course. Off to work through the Android courses now, but really looking forward to the next Java course! Keep up the excellent work!