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Java Java Data Structures Organizing Data Comparable

Udayakumar T
Udayakumar T
11,544 Points
Posted by Udayakumar T
Udayakumar T
11,544 Points

Hi, Please help me...

HI,

I have checked and returned the creation date in compare to method,but still task 1 is no longer is passing.

Please help me....

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;
  }

 @Override
public int compareTo(Object obj){
  BlogPost ob = (BlogPost) obj;
  if(this.equals(ob)){
    return 0; 
  }
  int cmp = this.mCreationDate.compareTo(mCreationDate);
  if(cmp==0){
    return this.mCreationDate.compareTo(mCreationDate);
  }
  return 1; 
}

}

1 Answer

markmneimneh
markmneimneh
14,132 Points
markmneimneh
markmneimneh
14,132 Points

Hello

I think you have a minor type in your class. This is my version.

    @Override
    public int compareTo(Object obj){
        BlogPost ob = (BlogPost) obj;
        if(this.equals(ob)){
            return 0;
        }
        int cmp = this.mCreationDate.compareTo(ob.mCreationDate);
        if(cmp==0){
           return 0;
        }
        return 1;
    }

and I created this simple main class for you test test:


import java.time.Instant;
import java.util.Date;

public class Main {

    public static void main(String[] args) {
        Instant instant1 = Instant.now().minusSeconds(36000);
        Instant instant2 = Instant.now().plusSeconds(36000);
        BlogPost bp1 = new BlogPost("me", "mine", "My Post", "Funny", Date.from(instant1));
        BlogPost bp2 = new BlogPost("me", "mine", "My Post", "Funny", Date.from(instant2));
        BlogPost bp3 = new BlogPost("me", "mine", "My Post", "Funny", Date.from(instant1));
        //
        //test 1
        if(bp1.compareTo(bp2) ==0){
            System.out.println("Yep, bp1 and bp2 are equal");
        }else{
            System.out.println("Nope, bp1 and bp2 are not equal");

        }
        //
        //test 2
        if(bp1.compareTo(bp3) ==0){
            System.out.println("Yep, bp1 and bp3 are equal");
        }else{
            System.out.println("Nope, bp1 and bp3 are not equal");

        }
    }
}

this should return the following from your class compareTo:

Nope, bp1 and bp2 are not equal
Yep, bp1 and bp3 are equal