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Java Java Data Structures - Retired Organizing Data Comparable

Posted by Matthew Germeyer
Matthew Germeyer
12,374 Points

Java Data Structures - compareTo implementation. Challenge Task 2 of 3.

My code compiles but I'm getting error message "Bummer: The compareTo method should always return 1". The directions seem to ask for the code to return 0 if the casted Object is equal to the original object. Am I missing something?

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

import java.util.Date;

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

  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 int compareTo(Object obj){

        if (obj.equals((BlogPost) obj)) {
          return 0;
        }

  return 1;
  }

}
Matthew Germeyer
Matthew Germeyer
12,374 Points

Additionally, when I just cast the object to a BlogPost without returning 0 I get: "Bummer: When an object equals another, the compareTo method should return 0. Current method returned 1."

Edit: The following code worked to satisfy the challenge step. public int compareTo(Object obj){ if (equals(obj)){ return 0; } return 1; }

Matthew Germeyer
Matthew Germeyer
12,374 Points

Conceptually, I think what I'm struggling with is why [ if (equals(obj)) ] knows to compare the caller of the equals method to the obj variable. Obviously there is nothing else it would be comparing to but syntactically this just seems odd. Any thoughts?