spring boot modules via Maven do not interact

Question

I’m using Spring Boot to create a Restful web service and a SOAP, each in a module but both in a single project.  So I decided to separate my domain layer into a third module since it’s the same for both types of web services and so could reuse. Even with the dependency between packages in Maven, when I run the application, it questions that, for example, PessoaRepository, which is the domain module and is being injected via @Autowired in Resource PessoaResource restful module, could not be injected by not being a Bean recognized by Spring:

Field pessoaRepository in br.com.tassioauad.restful.resource.PessoaResource required a bean of type 'br.com.tassioauad.domain.repository.PessoaRepository' that could not be found.

My breakup was like this:

Domain Module

pom.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>

        <groupId>br.com.tassioauad</groupId>
        <artifactId>domain</artifactId>
        <version>0.5</version>
        <packaging>jar</packaging>
        <name>domain</name>
        <description>Camada de Domínio</description>

        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>

        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.10.RELEASE</version>
            <relativePath/>
        </parent>

        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-annotations</artifactId>
                <version>RELEASE</version>
            </dependency>
            <dependency>
                <groupId>javax.validation</groupId>
                <artifactId>validation-api</artifactId>
            </dependency>
        </dependencies>

    </project>

Pessoarepository.java

public interface PessoaRepository extends CrudRepository<Pessoa, Integer>{

    //....

}

Módulo Restful

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>br.com.tassioauad</groupId>
    <artifactId>restful</artifactId>
    <version>0.5</version>
    <packaging>jar</packaging>

    <name>restful</name>
    <description>RESTFul API</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-hateoas</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-undertow</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>br.com.tassioauad</groupId>
            <artifactId>domain</artifactId>
            <version>0.5</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Pessoaresource.java

import br.com.tassioauad.domain.repository.PessoaRepository;

@RestController
@RequestMapping("/pessoa")
public class PessoaResource {

    @Autowired
    PessoaRepository pessoaRepository;

    //...
}

What is missing so that the Repository of one module is recognized in another module?

Answer 1

This usually happens when you separate the project into several modules. It turns out that Spring cannot perform the scan of components, entities, positions and services from one module to another in certain situations. Therefore, it is important to inform the basic path from where they are to carry out the scan. In this case, we are dealing with JPA repositories, so let’s put Annotation @EnableJpaRepositories in the class containing the main method:

@EnableJpaRepositories("br.com.tassioauad.domain")
@SpringBootApplication
public class RestfulApplication {

    public static void main(String[] args) {
        SpringApplication.run(RestfulApplication.class, args);
    }
}

This will not solve everything, there will be an error stating about not having found the entity Pessoa. That’s because he only became able to do scan in JPA repositories, but not in @Entity. To this we will add another anottation and now everything will be OK:

@EnableJpaRepositories("br.com.tassioauad.domain")
@EntityScan("br.com.tassioauad.domain")
@SpringBootApplication
public class RestfulApplication {

    public static void main(String[] args) {
        SpringApplication.run(RestfulApplication.class, args);
    }
}