Spring provides a very useful interface called Repository.

It is very useful. It is defined as follows

public interface CrudRepository<T, ID extends Serializable>
    extends Repository<T, ID> {

 

    T save(T entity);    //Saves the given entity.

 

    T findOne(ID primaryKey);  //Returns the entity identified by the given id.

Iterable<T> findAll();  //Returns all entities.

    Long count();   //Returns the number of entities.

 

    void delete(T entity);  //Deletes the given entity.

boolean exists(ID primaryKey);  //Returns whether an entity with the given id exists.


// … more functionality omitted.

}

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