Programming Kotlin

Creating a Repository Interface

Spring’s CrudRepository interface provides all the methods like findById() and save() to fetch from the database or to update the database. All we need to do is define a specialized interface to extend the CrudRepository. Spring Data will generate implementations for interfaces that extend CrudRepository.

If we were writing in Java, we’d write something like:

//Java code only for comparison purpose
package com.agiledeveloper.todo;

import org.springframework.data.repository.CrudRepository;

interface TaskRepository extends CrudRepository<Task, Long> {
}

The Kotlin code isn’t too different from that: there’s no need for ; or {}, and we replaced extends with :. Let’s write the Kotlin equivalent ...