Pagination with Sorting — Sample

A minimal demonstration of offset-based pagination with sorting in Java.

What It Demonstrates

Extends the basic pagination sample with sorting support. Before slicing the dataset into pages, the repository sorts the full list by the comparator provided in the request — so the order of records is consistent across all pages.

The project illustrates this with a concrete example: a CustomerRepository that accepts a Pageable request with a Comparator<Customer> and returns a sorted Page<Customer>.

Structure

The entire project intentionally fits in a single file — so the mechanics are visible in full, without unnecessary noise:

PaginationSorting.java
│
├── Customer                # Model — record with id and name
├── Page<T>                 # Pagination result — content + metadata (page, size, total)
├── Pageable                # Pagination request — page number, size and sort comparator
├── CustomerRepository      # Data access — sorts then paginates
├── FakeCustomerTable       # In-memory data source — simulates a database table
└── PaginationSorting       # Entry point + demo()

Key Points

Pageable carries a Comparator<Customer> alongside page number and size — the sort order is part of the request.

Sorting happens before pagination. The full dataset is sorted first, then sliced — this ensures consistent ordering across all pages.

CustomerRepository copies the source list before sorting — the original data source is never mutated.

Console Output

Page[content=[Customer[id=1, name=Alice], Customer[id=2, name=Bob], Customer[id=3, name=Charlie]], page=0, size=3, total=5]

Page[content=[Customer[id=5, name=Eve], Customer[id=4, name=Diana], Customer[id=3, name=Charlie]], page=0, size=3, total=5]

First result — sorted by name ascending. Second result — sorted by id descending.