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Pagination with stream

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#1

Hi, is there any way with the concept of stream to do pagination like return firstpage, lastpage,previousPage, size, totalelements etc!
thanks

Course: Java 8 for Experienced Developers: Lambdas, Stream API & Beyond - Learn Interactively
Lesson: Method References - Java 8 for Experienced Developers: Lambdas, Stream API & Beyond

#2

Hi @ayman!!
Yes, you can implement pagination using streams in Java. However, streams in Java are more suitable for processing data in a sequential or parallel manner rather than for direct pagination. Pagination is typically done on collections or data sources that support random access, such as lists.

That being said, you can still achieve pagination with streams by converting your data source into a stream and then applying stream operations to manipulate the data. Here’s a basic example of how you can implement pagination with streams:

import java.util.List;
import java.util.stream.Collectors;

public class PaginationDemo {

    public static void main(String[] args) {
        // Sample list of data
        List<Integer> dataList = List.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

        int pageSize = 3; // Number of elements per page
        int pageNumber = 2; // Page number to retrieve (1-indexed)

        // Calculate start and end index for pagination
        int startIndex = (pageNumber - 1) * pageSize;
        int endIndex = Math.min(startIndex + pageSize, dataList.size());

        // Get sublist for the specified page
        List<Integer> pageData = dataList.stream()
                .skip(startIndex)
                .limit(endIndex - startIndex)
                .collect(Collectors.toList());

        // Display page data
        System.out.println("Page Number: " + pageNumber);
        System.out.println("Page Size: " + pageData.size());
        System.out.println("Total Elements: " + dataList.size());
        System.out.println("Page Data: " + pageData);
    }
}

In this example:

  • We have a sample list of integers (dataList).
  • We specify the pageSize and the pageNumber to retrieve.
  • We calculate the startIndex and endIndex based on the page size and page number.
  • We use skip() and limit() stream operations to get the sublist for the specified page.
  • Finally, we collect the page data into a new list using collect(Collectors.toList()).

You can further enhance this code to implement additional pagination features such as retrieving the first page, last page, and previous page by adjusting the pageNumber parameter accordingly. Additionally, you can calculate the total number of pages based on the total number of elements and the page size.
I hope it helps. Happy Learning :blush: