How to Use EntityListener for Effective Audit Trails in Spring

1. Overview

An audit trail is important in persisting entities using JPA because it helps maintain data integrity and ensure compliance with regulatory requirements. An audit trail records a history of changes made to data over time, including who made the changes and when. By implementing an audit trail, you can track and verify any changes made to data, and identify any unauthorized or unexpected modifications. This can help detect and prevent data tampering, and provide transparency into data changes made by different users over time.

In the context of JPA, audit trails can be implemented using various techniques, including adding auditable columns to database tables or using interceptors to capture changes made to entities before they are persisted in the database. By including an audit trail in your JPA application, you can maintain a comprehensive history of changes made to data, which can be useful for various purposes such as auditing, compliance, and troubleshooting.

Overall, implementing an audit trail can provide greater transparency and accountability for data changes in your JPA application, which can help ensure data integrity and protect against unauthorized access or data tampering.

2. Hands-on Coding

Spring-data-jpa provides a convenient solution for implementing audit trails in your Java applications, and in this tutorial, we'll show you how to use it to quickly get started with auditing your classes.

2.1 Auditable Entity

An abstract class where we will store the audit information such as date and user. It should be annotated with AuditingEntityListener from spring-data-jpa. I'm using Lombok dependency for getter and setter here.

@Data
@SuperBuilder
@MappedSuperclass
@NoArgsConstructor
@EntityListeners(AuditingEntityListener.class)
public abstract class AuditableEntity extends BaseEntity {

  @Column(name = "created_at", nullable = false, updatable = false)
  @CreatedDate
  private LocalDateTime createdAt;

  @Column(name = "updated_at", nullable = false)
  @LastModifiedDate
  private LocalDateTime updatedAt;

  @Column(name = "created_by", nullable = false, updatable = false)
  @CreatedBy
  private String createdBy;

  @Column(name = "updated_by", nullable = false)
  @LastModifiedBy
  private String updatedBy;
}

2.2 Auditor Information

A class where we can get the currently logged user using SecurityContextHolder or a constant for system user.

public class AuditorAwareImpl implements AuditorAware<String> {

  @Override
  public Optional<String> getCurrentAuditor() {
    return Optional.of("SYSTEM");
  }
}

2.3 Jpa Configuration

We need to tell Spring context where to pull the auditor information as such we need to add this configuration.

@Configuration
@EnableJpaAuditing(auditorAwareRef = "auditorProvider")
@EnableTransactionManagement
public class JpaConfig {

  @Bean
  public AuditorAware<String> auditorProvider() {
    return new AuditorAwareImpl();
  }

}