How do I do this if I don't. know where the blog posts are instantiated; I don't have any array of all the blog posts

package com.example;
import java.util.Arrays;
import java.util.Comparator;
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 object){
    BlogPost blogPost = (BlogPost) object;
    if(equals(blogPost)){
      return 0;
    }
    return 1;
  }

}