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Java Java Data Structures - Retired Exploring the Java Collection Framework Upgrade Comparable to use Generics

i'cant understand what's going on

I'am repeatedly trying to solve this problem but I cant solve it plz tell me what's going wrong?????

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

import java.io.Serializable;
import java.util.Date;

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(Object obj) {

    if (equals(other)) {
      return 0;
    }
    return mCreationDate.compareTo(other.mCreationDate);
  }

  public String[] getWords() {
    return mBody.split("[^\\w']+");
  }

  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

Paolo Bass
Paolo Bass
3,921 Points

Hi Ashmit,

the compareTo() method must have a BlogPost rather than an Object in the parameter:

Also, you need to change the name of 'obj' to 'other'. I would also advise to use the getter method to access the mCreationDate variable.

public int compareTo(BlogPost other) {

if (equals(other)) {
  return 0;
}
return mCreationDate.compareTo(other.getCreationDate());

}