This document describes how to modularize a Spring Boot application using the Moduliths framework. It shows how to configure Moduliths dependencies and annotations, run module tests, and handle module dependencies and exposed/private types between modules. It demonstrates generating module diagrams from the application code using the Moduliths documenter tool.

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Spring I/O 2019
Spring I/O 2018
Spring I/O 2017

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11. <dependency>
<groupId>de.olivergierke.moduliths</groupId>
<artifactId>moduliths-test</artifactId>
<version>${moduliths.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>de.olivergierke.moduliths</groupId>
<artifactId>moduliths-docs</artifactId>
<version>${moduliths.version}</version>
<scope>test</scope>
</dependency>
<repositories>
<repository>
<id>spring-snapshots</id>
<url>https://repo.spring.io/libs-snapshot</url>
</repository>
</repositories>
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12. @Modulith // Instead of @SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
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17. @ModuleTest // Instead of @SpringBootTest
class CatalogTests {
}
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18. ...SKIP...
Bootstrapping @ModuleTest for in mode
DIRECT_DEPENDENCIES (class
com.example.demo.DemoApplication)…
=======================================================
==========
## ##
> Logical name: order
> Base package: com.example.demo.order
> Direct module dependencies: inventory
> Spring beans:
+ ….OrderRepository
o ….internal.OrderServiceImpl
o ….web.OrderController
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==========================================================
Included dependencies:
==========================================================
## ##
> Logical name: inventory
> Base package: com.example.demo.inventory
> Direct module dependencies: none
> Spring beans:
+ ….StockRepository
+ ….internal.InventoryServiceImpl
==========================================================

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22. . ____ _ __ _ _
/ / ___'_ __ _ _(_)_ __ __ _
( ( )___ | '_ | '_| | '_ / _` |
/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |___, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.2.0.BUILD-SNAPSHOT)
…Skip…
java.lang.IllegalStateException: Module 'order' depends on non-exposed type
com.example.demo.catalog.internal.PrivateSample within module 'catalog'!
Method
<com.example.demo.order.internal.OrderServiceImpl.completeOrder(com.example.demo.order.Order)
> calls constructor <com.example.demo.catalog.internal.PrivateSample.<init>()> in
(OrderServiceImpl.java:25)
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@EventLisetner

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public abstract class AbstractAggregateRoot<PK extends Serializable> extends AbstractPersistable<PK> {
@JsonIgnore
private final transient List<Object> domainEvents = new ArrayList<>();
@DomainEvents
public List<Object> getDomainEvents() {
return this.domainEvents;
}
protected <T> T registerEvent(T event) {
Assert.notNull(event, "Domain event must not be null!");
this.domainEvents.add(event);
return event;
}
}
@Component
@RequiredArgsConstructor
class InventoryServiceImpl implements InventoryService {
private final ProductRepository productRepository;
@EventListener
public void on(Order.OrderCompleted event) {
// do something...
}
}

27. @MockBean
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@MockBean

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public class DemoApplicationTests {
@Test
void verifyModularity() throws IOException {
// Generate documentation
Documenter documenter = new Documenter(modules);
Documenter.Options options = Documenter.Options.defaults() //
.withExclusions(module -> module.getName().matches(".*core|.*support"));
// Write overall diagram
documenter.writeModulesAsPlantUml(options);
// Write diagrams for each module
modules.stream().forEach(it -> documenter.writeModuleAsPlantUml(it, options));
}
}

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• = Spring I/O 2019 - Moduliths
OGAWA, Takeshi;
:generated-docs: ../../../target/generated-docs
:toc:
:revnumber: {version}
:revdate: {localdate}
:imagesdir: ./images
plantuml::{generated-docs}/moduliths/components.uml[…]
plantuml::{generated-docs}/moduliths/module-catalog.uml[…]
plantuml::{generated-docs}/moduliths/module-order.uml[…]
plantuml::{generated-docs}/moduliths/module-inventory.uml[…]

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