How to get different values from two ArrayList in Java/Android?

Question

I have two List

Class Article

public class Article{
 int id;
 String name;

// get
// set

}

List one:

List<Article> mListInfor have

id =  1, 2 , 3, 4, 5
name = "A", "B", "C", "D", "E"

List Two:

List<Article> mListNews have

id =   1, 2, 3, 4, 5, 6, 7, 8

name = "A", "B", "C", "D", "E", "F", "G", "H"

Result:

List<Article> mListDiffrent have

id = 6,7,8

name = "F","G","H"

How can I get different value from these two arraylists: List mListInfor and List mListNews ?

Please. Help me!

Is ID is unique to identify an article?

T D Nguyen
– T D Nguyen

2016-03-14 03:29:59 +00:00
Commented Mar 14, 2016 at 3:29 — T D Nguyen
– T D Nguyen, Commented Mar 14, 2016 at 3:29

rafaelc · Accepted Answer · 2016-03-14 03:40:38Z

2

You should override the Equals method in your class, and then use some built-in methods. For example

public class Article{
    int id;
    String name;

    // get
    // set
    @Override
    public boolean equals(Object obj) {
       if (!(obj instanceof Article))
          return false;
       if (obj == this)
          return true;
       return this.id == obj.id;
    }
} 

List<Article> differences = new ArrayList<>();
differences.addAll(mListInfor)
differences.removeAll(mListNews)

Edit

Depending on the order of your call to removeAll, the result can be affected. However, there is a already-built feature in apache commons (CollectionUtils) which will make you not worry about that.

CollectionUtils.intersection(mListInfor, mListNews);

edited Mar 14, 2016 at 3:40

answered Mar 14, 2016 at 3:30

rafaelc

59.4k15 gold badges64 silver badges87 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Parth Joshi · Accepted Answer · 2016-03-14 03:43:32Z

-1

Solution given by @rafael in above answer is good solution where you are using inbuilt feature.

You can also create a function where you can individually traverse each element of article lost and segregate by using comparator implementation or even equals comparison is good.

Also don't forget to explore streams in Java 8. There must be good options in stream api.

answered Mar 14, 2016 at 3:43

Parth Joshi

4624 silver badges6 bronze badges

2 Comments

T D Nguyen Over a year ago

This should be a comment rather than an answer!

OneCricketeer Over a year ago

Android doesn't have Java 8 support. Look at the tags. It's an Android question.

Collectives™ on Stack Overflow

How to get different values from two ArrayList in Java/Android?

2 Answers 2

Edit

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Edit

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related