Unable to locate the jar in Maven Dependency Management

Question

I have 2 projects testing.parent and testing.child. The project structure is as below:

Their individual poms are as below:

testing.parent

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>testing.group</groupId>
    <artifactId>testing.parent</artifactId>
    <version>1.0</version>
    <packaging>pom</packaging>
    <name>testing.parent</name>
    <url>http://maven.apache.org</url>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>1.2.17</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

testing.child

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>testing.group</groupId>
    <artifactId>testing.child</artifactId>
    <version>1.1</version>
    <packaging>jar</packaging>
    <name>testing.child</name>
    <url>http://maven.apache.org</url>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>testing.group</groupId>
                <artifactId>testing.parent</artifactId>
                <version>1.0</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

In order to test the dependency management I tried to import the log4j jar to child project but still the jar is not available in the child project. Is this the correct way to import the jars?

Have you taken a look at this link? https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html — vs97, Nov 25 '18 at 03:30

score 1 · Accepted Answer · answered Nov 25 '18 at 04:25

1

Is this the correct way to import the jars?

Yes, include the log4j in the dependency section of the child pom.xml.

<dependencies>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version> <!-- version is optional when using dependency management -->
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
</dependencies>

Also, make sure to refer the parent from the child as well, include the following in child pom.xml for that:

<parent>
    <artifactId>testing.parent</artifactId>
    <groupId>testing.group</groupId>
    <version>1.0</version>
</parent>

ensuring the similar reference in the parent pom.xml as

<modules>
    <module>testing.child</module>
</modules>

answered Nov 25 '18 at 04:25

Naman

27,789
26
218
353

If I specifically need to include the log4j seperately in the dependency section then whats the use of having the dependency management section? I could have done the same thing without having all the additional sections of parent, dependency management etc and directly including the log4j. – ghostrider Nov 25 '18 at 04:33
1

*dependency management section* is mostly to control the version of the dependencies in a centralised way. you can read more about it in the docs https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Dependency_Management – Naman Nov 25 '18 at 04:38
So just to conclude, in my case only importing the parent dependencies in dependency management wont make the log4j jar available in child. I have to additionally include it in the dependency section as well right? – ghostrider Nov 25 '18 at 05:48
1

@ghostrider Yes, unless it's anyway *available via some transitive dependencies* – Naman Nov 25 '18 at 05:59

score 0 · Answer 2 · answered Nov 25 '18 at 06:18

0

If you add below part to child pom.xml file, you don't need to import lof4j dependency separately though child pom.xml.

<parent>
    <artifactId>testing.parent</artifactId>
    <groupId>testing.group</groupId>
    <version>1.0</version>
</parent>

answered Nov 25 '18 at 06:18

WGSSAMINTHA

180
1
11

I am aware of this. I wanted to check the benefits of dependency management. For dependency management its a 2 step process right? – ghostrider Nov 25 '18 at 07:19

Unable to locate the jar in Maven Dependency Management

2 Answers2