How to move all the common dependencies from maven module into parent module in spring boot

Question

I have two simple Spring Boot applications, one is a eureka-server and another is an eureka-client . Both of them reside in a maven aggregator module eureka-sample .

I have some common dependencies in both the eureka-server and eureka-client applications that I would like to move up to the parent pom so that I do not have to include them in each of the child modules every now and then.

I tried moving the dependency spring-boot-starter-test from the child modules into the parent pom under <dependencyManagement> section but then the tests in the child module were not able to compile as those classes were not able to find the jar . May be I misconfigured or placed it under wrong section.

How can I achieve this?

eureka-sample (parent 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>com.study.spring</groupId>
    <artifactId>eureka-sample</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>
    <name>eureka-sample</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Dalston.SR4</spring-cloud.version>
    </properties>

    <modules>
        <module>eureka-server</module>
        <module>eureka-client</module>
    </modules>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.8.RELEASE</version>
        <relativePath />
    </parent>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

</project>

eureka-server/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>
    <artifactId>eureka-server</artifactId>
    <packaging>jar</packaging>
    <name>eureka-server</name>
    <description>Demo project for Spring Boot</description>
    <parent>
        <groupId>com.study.spring</groupId>
        <artifactId>eureka-sample</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>

        **<!-- ALL THE FOLLOWING 3 DEPENDENCIES SHOULD GO TO PARENT POM SO THAT I DO NOT HAVE TO PUT THEM IN EVERY CHILD MODULE -->**
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

eureka-client/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>
    <artifactId>eureka-client</artifactId>
    <packaging>jar</packaging>
    <name>eureka-client</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>com.study.spring</groupId>
        <artifactId>eureka-sample</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        **<!-- ALL THE FOLLOWING 3 DEPENDENCIES SHOULD GO TO PARENT POM SO THAT I DO NOT HAVE TO PUT THEM IN EVERY CHILD MODULE -->**
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

Answer 1

Try putting the common dependencies inside the <dependencies> section of the parent .pom instead of the <dependencyManagement> section.

With <dependencyManagement> you only prepare and configure the dependencies for all children modules, but in order to actually use them, you'll still need to reference them from within the child module.

The difference is subtle, but important - see https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html for details.