Introducción
¿Qué es Spring Data?
Crear proyecto con Spring Initializr
Primeros pasos
Conectar el proyecto a la base de datos
Crear entidades con JPA
Crear relaciones entre entidades
Usar jdbcTemplate para consultas
Spring Data Repositories
Spring Data Repositories
Crear un nuevo registro con CrudRepository
Borrando registros
Usar Lazy y Eager al cargar relaciones
Query Methods: And, Or, True, IgnoreCase, OrderBy
Query Methods: Contains, Not
Query Methods: After, Before, Between, Count, In
Query Methods: First, Top, Optional, LessThan, GreaterThan
Paginación en las consultas
Ordenando la información paginada
Personalización de queries
Usar la anotación @Query con JPQL
Usar @Query con SQL nativos
Resultado personalizado con @Query
Usar @Modifying en un @Query
ACID: @Transactional para asegurar la atomicidad
Características avanzadas
Auditoría con Spring Data
Crear listener personalizado para auditoría
Ejecutar un stored procedure
Próximos pasos
Toma el Curso de Spring Security
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Auditing a database is fundamental to maintain the integrity and control of the modifications in our entities. Today we are going to learn how to audit all the operations in our "PIXA" entity using a custom listener. This mechanism will not only monitor the creation or modification dates, but also any change in your data.
A listener is a class with methods that react to entity lifecycle events. By creating a listener specific to our PIXA entity, we will be able to track events such as the creation, update or deletion of records.
Create the audit package: Start by creating a new package called audit inside the persistence folder, where you can group all the necessary listeners.
Define the AuditPIXAListener class: This class will manage the auditable events. It implements specific methods using annotations such as @PostPersist, @PostUpdate, and @PreRemove.
Use of annotations for methods:
public void onPostPersist(PIXAEntity entity) { System.out.println("Entity: " + entity.toString());}public void onPreRemove(PIXAEntity entity) { System.out.println("Preparing to remove: " + entity.toString());}Implement toString for PIXAEntity: Make sure that the PIXAEntity class has a toString method that includes all relevant data to facilitate visual auditing of previous and current data.
The postLoad method allows you to audit the values before a modification by loading the current state of the entity. For this:
SerializationUtils to clone the entity and avoid overwriting in memory.@PostLoadpublic void postLoad(PIXAEntity entity) { this.currentValue = SerializationUtils.clone(entity); System.out.println("Current state loaded.");}When we modify a field, when we make a request, you will notice in the console how the system prints both the previous state and the new one:
postLoad, update, and finally postPersist."oldValue: motherboard, newValue: holymotherherd".It is important to always commit changes by verifying that the ID is consistent, especially in update operations. The results obtained can be sent to databases for historical records or even to log files.
Finally, remember that this type of auditing is effective when using Spring Data Repositories lifecycle methods such as save. For native queries, these processes will not be transparent.
Continue exploring ways to improve your entity management with Spring Data JPA, and don't forget to join me in the next class to discover how to execute stored procedures using this powerful tool. Keep learning and expanding your skills!
Contributions 5
Questions 4
También se puede usar la anotación @ToString de lombok para no sobrescribir el método toString() en la clase, adicionalmente se pueden excluir campos de la salida:
import lombok.ToString;
@ToString
public class ToStringExample {
private static final int STATIC_VAR = 10;
private String name;
private Shape shape = new Square(5, 10);
private String[] tags;
@ToString.Exclude private int id;
...
}
Luego de implementar el metodo toString() en la clase PizzaEntity, ya luego en la clase AuditPizzaListener no es necesario para las instancias de objeto entidad invocar explicitamente el metodo toString(), solo con imprimir el objeto directamente ya por default invoca el metodo toString(), entonces tando para insert, update o delete funciona.
Las anotaciones @PrePersist, @PreUpdate, @PreRemove, @PostPersist, @PostUpdate y @PostRemove que llevan los métodos se podrían asemejar a los Triggers de base de datos relaciones.
Aquí sería mejor cargar el valor anterior en el @PreUpdate, con eso se garantizaría que el valor en currentValue sea el correcto.
sorry, código Kotlin:
@PreUpdate
fun onPreUpdate(entity: PizzaEntity) {
currentValue = entity.copy()
}
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