Spring Data JPA Auditing: Saving CreatedBy, CreatedDate, LastModifiedBy, LastModifiedDate automatically

In any business application auditing simply means tracking and logging every change we do in the persisted records which simply means tracking every insert, update and delete operation and storing it.

Auditing helps us in maintaining history records which can later help us in tracking user activities. If implemented properly auditing can also provide us similar functionality like version control systems.

I have seen projects storing these things manually and doing so become very complex because you will need to write it completely by your own which will definitely require lots of code and lots of code means less maintainability and less focus on writing business logic.

But why should someone need to go to this path when both JPA and Hibernate provides Automatic Auditing which we can be easily configured in your project.

And here in this article, I will discuss how we can configure JPA to persist CreatedBy, CreatedDate, LastModifiedBy, LastModifiedDate columns automatically for any entity.




I will walk you through to the necessary steps and code portions you will need to include in your project to automatically update these properties. We will use Spring Boot, Spring Data JPA, MySql to demonstrate this. We will need to add below parent and dependencies to our pom file

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.1.RELEASE</version>
    <relativePath/>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>

Spring Data Annotations @CreatedBy, @CreatedDate, @LastModifiedBy and @LastModifiedDate

Let’s suppose we have a File entity and a single record in file table stores name and content of the file and we also want to store who created and modified any file at what time. So we can keep track like when the file was created by whom and when it was last modified by whom.

So we will need to add name, content, createdBy, createdDate, lastModifiedBy, lastModifiedDate properties to our File entity and to make it more appropriate we can move createdBy, createdDate, lastModifiedBy, lastModifiedDate properties to a base class Auditable and annotate this base class by @MappedSuperClass and later we can use the Auditable class in other audited entities.

You will also need to write getters, setters, constructors, toString, equals along with these fields. However, you should take a look at Project Lombok: The Boilerplate Code Extractor, if you want to auto-generate these things.

Both classes will look like

@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
public abstract class Auditable<U> {

    @CreatedBy
    protected U createdBy;

    @CreatedDate
    @Temporal(TIMESTAMP)
    protected Date creationDate;

    @LastModifiedBy
    protected U lastModifiedBy;

    @LastModifiedDate
    @Temporal(TIMESTAMP)
    protected Date lastModifiedDate;

    // Getters and Setters

}

@Entity
public class File extends Auditable<String> {
    @Id
    @GeneratedValue
    private int id;
    private String name;
    private String content;

    // Getters and Setters
}

As you can see above I have used @CreatedBy, @CreatedDate, @LastModifiedBy and @LastModifiedDate annotation on respective fields.

Spring Data JPA approach abstracts working with JPA callbacks and provides us these fancy annotations to automatically save and update auditing entities.

Using AuditingEntityListener class with @EntityListeners

Spring Data JPA provides a JPA entity listener class AuditingEntityListener which contains the callback methods (annotated with @PrePersist and @PreUpdate annotation) which will be used to persist and update these properties when we will persist or update our entity.

JPA provides the @EntityListeners annotation to specify callback listener classes which we use to register our AuditingEntityListener class.

However, We can also define our own callback listener classes if we want to and specify them using @EntityListeners annotation. In my next article, I will demonstrate how we can use @EntityListeners to store audit logs.

Auditing Author using AuditorAware and Spring Security

JPA can analyze createdDate and lastModifiedDate using current system time but what about the createdBy and lastModifiedBy fields, how JPA will recognize what to store in these fields?

To tell JPA about currently logged in user we will need to provide an implementation of AuditorAware and override getCurrentAuditor() method. And inside getCurrentAuditor() we will need to fetch currently logged in user.

As of now, I have provided a hard-coded user but you are using Spring security then you use it find currently logged in user same as I have mentioned in the comment. 

public class AuditorAwareImpl implements AuditorAware<String> {

    @Override
    public String getCurrentAuditor() {
        return "Naresh";
        // Can use Spring Security to return currently logged in user
        // return ((User) SecurityContextHolder.getContext().getAuthentication().getPrincipal()).getUsername()
    }
}

Enable JPA Auditing by using @EnableJpaAuditing

We will need to create a bean of type AuditorAware and will also need to enable JPA auditing by specifying @EnableJpaAuditing on one of our configuration class. @EnableJpaAuditing accepts one argument auditorAwareRef where we need to pass the name of the AuditorAware bean.

@Configuration
@EnableJpaAuditing(auditorAwareRef = "auditorAware")
public class JpaConfig {
    @Bean
    public AuditorAware<String> auditorAware() {
        return new AuditorAwareImpl();
    }
}

And now if we will try to persist or update and file object CreatedBy, CreatedDate, LastModifiedBy, LastModifiedDate properties will automatically get saved.

In the next article JPA Auditing: Persisting Audit Logs Automatically using EntityListeners, I have discussed how we can use JPA EntityListeners to create audit logs and generate history records for every insert, update and delete operation.

You can find complete code on this Github Repository and please feel free to give your valuable feedback.