Spring Data MongoDB 1.2.0 silently introduced new feature: support for basic auditing. Because you will not find too much about it in official reference in this post I will show what benefits does it bring, how to configure Spring for auditing and how to annotate your documents to make them auditable.Auditing let you declaratively tell Spring to store:
- date when document has been created: @CreatedDate
- date when document has been updated last time: @LastModifiedDate
- user who has created document: @CreatedBy
- user who has done most recent update: @LastModifiedBy
- current document version: @Version
Configuration
First of all Maven dependencies to latest Spring Data MongoDB and Spring Data Commons. Additionally in order to use date-related audit annotations we need to add joda-time to classpath.
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-mongodb</artifactId>
<version>1.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-commons</artifactId>
<version>1.5.1.RELEASE</version>
</dependency>
<dependency>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
<version>2.2</version>
</dependency>In order to enable auditing we need to add <mongo:auditing/> to Spring configuration. Currently there is no way to configure it through Java Config.
<mongo:auditing />
<mongo:mongo id="mongo" />
<bean class="org.springframework.data.mongodb.core.MongoTemplate">
<constructor-arg name="mongo" ref="mongo" />
<constructor-arg name="databaseName" value="blog-tests" />
</bean>Usage
Configuration above provides us way for auditing that includes versioning and timestamps. Example document will look like:
@Document
public class Item {
@Id
private String id;
...
@Version
private Long version;
@CreatedDate
private DateTime createdAt;
@LastModifiedDate
private DateTime lastModified;
...
}Now you can save document using MongoTemplate or your repository and all annotated fields are automagically set.
As you have probably noticed I did not use here user related annotations @CreatedBy and @LastModifiedBy. In order to use them we need to tell Spring who is a current user.
First add user related fields to your audited class:
@CreatedBy private String createdBy; @LastModifiedBy private String lastModifiedBy;
Then create your implementation of AuditorAware that will obtain current user (probably from session or Spring Security context – depends on your application):
public class MyAppAuditor implements AuditorAware<String> {
@Override
public String getCurrentAuditor() {
// get your user name here
return "John Doe";
}
}Last thing is to tell Spring Data MongoDB about this auditor aware class by little modification in Mongo configuration:
<mongo:auditing auditor-aware-ref="auditor" /> <bean id="auditor" class="pl.maciejwalkowiak.blog.MyAppAuditor"/>
The created date is missing on update. Is there a way to keep persisting this on update?