Still need in-memory DB or datasource setting when use MongoDB as JobRepository

[weiz-cn]

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Bug description
Still need in-memory DB or datasource setting when use MongoDB as JobRepository.
Environment
Spring batch 5.2, Java 17

Steps to reproduce
Create a spring-boot application, use MongoDB as JobRepository following https://github.com/spring-projects/spring-batch/blob/main/spring-batch-core/src/test/java/org/springframework/batch/core/repository/support/MongoDBJobRepositoryIntegrationTests.java

Do not setup any datasource or in-memory DB, start the springboot application. Got following error:

2024-12-03T09:46:46.892+08:00  WARN 65662 --- [spring-batch-demo] [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'jobLauncherController': Unsatisfied dependency expressed through field 'jobLauncher': Error creating bean with name 'jobLauncher': Cannot resolve reference to bean 'jobRepository' while setting bean property 'jobRepository'
2024-12-03T09:46:46.894+08:00  INFO 65662 --- [spring-batch-demo] [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2024-12-03T09:46:46.899+08:00  INFO 65662 --- [spring-batch-demo] [           main] .s.b.a.l.ConditionEvaluationReportLogger : 

Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
2024-12-03T09:46:46.907+08:00 ERROR 65662 --- [spring-batch-demo] [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
	If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
	If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

Process finished with exit code 1

If I add hsqldb dependency to pom.xml. The application can start successfully. I tried to start the job, and I can see MongoDB is used as JobRepository.

Expected behavior
A clear and concise description of what you expected to happen.

Minimal Complete Reproducible example
https://github.com/weiz-cn/spring-batch-demo
You need a MongoDB as JobRepository to start the application

[fmbenhassine]

Thank you for reporting this. Indeed, this is a design issue with the Java configuration style that was inherited from the early version of EnableBatchProcessing (from which DefaultBatchConfiguration was designed similarly for consistency).

That said, there should be no issue with the XML configuration style where you can define the mongo job repository without the need for a datasource:

<bean id="jobRepository"
 class="org.springframework.batch.core.repository.support.MongoJobRepositoryFactoryBean"
 p:mongoOperations-ref="mongoOperations" p:transactionManager-ref="mongoTransactionManager" />

Have you tried that?

[weiz-cn]

p:transactionManager-ref

I got this, even I set spring.main.allow-bean-definition-overriding=true

***************************
APPLICATION FAILED TO START
***************************

Description:

The bean 'jobRepository', defined in class path resource [beans.xml], could not be registered. A bean with that name has already been defined and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true