Daily Archives: December 29, 2021

dependencyManagement as jar

Without specifying <packaging>xxx</packaging> in pom, the default is jar.

For project1, it is deployed to nexus. Then project2 can uses it as normal dependency rather than parent. project2 can still uses the version, scope inside dependencyManagement in project1. See below.

project1/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.test.pengli</groupId>
    <artifactId>project1</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>sts</artifactId>
                <version>2.17.74</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.6</version>
        </dependency>
    </dependencies>

</project>

 

project2/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.test.pengli</groupId>
    <artifactId>project2</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>sts</artifactId>
                <version>2.17.74</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>com.test.pengli</groupId>
            <artifactId>project1</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>sts</artifactId>
        </dependency>
    </dependencies>


    <pluginRepositories>
        <pluginRepository>
            <id>xxx</id>
            <name>Nexus</name>
            <url>http://nexus.xxx.com</url>
        </pluginRepository>
    </pluginRepositories>
</project>

When running mvn dependency:tree, it shows below. It actually same as result in dependencyManagement vs dependencies

dependency_tree2

 

dependencyManagement vs dependencies

dependencies uses the dependencies.

dependencyManagement doesn’t include dependencies in project. It is mainly defines dependencies and its version, scope. Sub project specifies parent to it. When sub project defines dependencies, it won’t need to specify version, scope.

pro1_2

project1/pom.xml

This pom.xml has <packaging>pom</packaging> property. In this case, it can be used as parent in sub project.

<?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.test.pengli</groupId>
    <artifactId>project1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging> // This is needed if we want this pom.xml to be a parent

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>sts</artifactId>
                <version>2.17.74</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.6</version>
        </dependency>
    </dependencies>

</project>

project2/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>

    <parent>
        <groupId>com.test.pengli</groupId>
        <artifactId>project1</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath>../project1</relativePath>
    </parent>

    <groupId>com.test.pengli</groupId>
    <artifactId>project2</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>sts</artifactId>  // No need to specify version. Parent pom did for us.
        </dependency>
    </dependencies>

</project>

In project2, when run mvn dependency:tree, it shows below:

dependency_tree