README.md

cursor-pagination-demo

This project demonstrates how to use keyset pagination without numeric offsets together with blaze-persistence and Spring Boot. This approach is also called cursor based pagination or seek pagination and is suitable for example for infinite scrolling.

Adapted from blaze-persistence-examples-spring-hateoas.

Running the Application

Launch the main class com.github.kekbur.cursorpaginationdemo.Application

Sample Request URLs

Description	URL
Retrieve first 10 cats	http://localhost:8080/cats
Retrieve first 10 cats whose name contains "3"	http://localhost:8080/cats?filter=%7B%22field%22:%22name%22,%22values%22:%5B%223%22%5D,%22kind%22:%22CONTAINS%22%7D
Retrieve all cats (no pagination)	http://localhost:8080/all-cats

The above requests sort cats by age (ascending) and secondarily by id (descending).

Use the "next" and "previous" links in the responses to navigate back and forward.

Sample Response

Note that the cat attributes are randomly generated when the application starts, so the "next" link below won't work for you.

{
    "next": "http://localhost:8080/cats?after=AgEAAAABAAAAAAAAAABg",
    "content": [
        {
            "id": 101,
            "name": "Cat 96",
            "age": 0,
            "owner": {
                "id": 4,
                "name": "Person 3"
            },
            "mother": null,
            "father": null
        },
        {
            "id": 87,
            "name": "Cat 82",
            "age": 0,
            "owner": {
                "id": 2,
                "name": "Person 1"
            },
            "mother": null,
            "father": null
        },
        <...>
    }
}

Generated SQL Queries

Retrieving the first 10 cats whose name contains "3":

<...> where cat0_.name like '%3%' order by cat0_.age ASC, cat0_.id DESC limit 10

Retrieving the next 10 cats:

<...> where (7, cat0_.id) < (cat0_.age, 35) and 0=0 and (cat0_.name like '%3%') order by cat0_.age ASC, cat0_.id DESC limit 10

Take note how the desired rows are found using a where condition instead of using a numeric offset. Such queries can be executed more efficiently as long as the tables have appropriate indexes. See https://use-the-index-luke.com/sql/partial-results/fetch-next-page for more information.