仅使用Maven依赖项类构建jar文件

Question

I have 2 projects, project A and project B. Project A is dependent on project B.

pom.xml of project A:

<dependencies>
    <dependency>
        <groupId>nft.dcs</groupId>
        <artifactId>B</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
</dependencies>

<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>3.1.1</version>
    <configuration>
        <appendAssemblyId>true</appendAssemblyId>

        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
    </configuration>

    <executions>
        <execution>
            <id>make-vision-plugin</id>
            <phase>package</phase>
            <goals>
                <goal>single</goal>
            </goals>
            <configuration>
                <descriptors>
                    <descriptor>src/assembly/dep.xml</descriptor>
                </descriptors>
            </configuration>
        </execution>
    </executions>
</plugin>

Next, I compile my project and it creates a jar with all the dependencies that I don't need. Created extra folders that do not have to be included in the jar file. I think these dependencies drag along with the dependency from project B. Using the dep.xml file, I indicate which folders you do not need to include in the jar file.

dep.xml :

<id>with-spec</id>
    <formats>
        <format>jar</format>
    </formats>
<includeBaseDirectory>false</includeBaseDirectory>
<dependencySets>
    <dependencySet>
        <outputDirectory>/</outputDirectory>
        <useProjectArtifact>false</useProjectArtifact>
        <unpack>true</unpack>
        <unpackOptions>
            <excludes>
                <exclude>nft/**</exclude>
                <exclude>com/**</exclude>
                <exclude>impl/**</exclude>
                <exclude>javax/**</exclude>
                <exclude>junit/**</exclude>
                <exclude>org/**</exclude>
                <exclude>oshi/**</exclude>
                <exclude>sound/**</exclude>
            </excludes>
        </unpackOptions>
        <scope>runtime</scope>
    </dependencySet>
</dependencySets>
<fileSets>
    <fileSet>
        <directory>${project.build.outputDirectory}</directory>
        <outputDirectory>/</outputDirectory>
    </fileSet>
</fileSets>

This method is just awful. Please tell me whether it is possible to add only classes from the dependency to the jar file and not to pull all these other folders.

Answer 1

You can try using scope provided:

<dependencies>
    <dependency>
        <groupId>nft.dcs</groupId>
        <artifactId>B</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

You should take into account that, as maven documentation states:

indicates you expect the JDK or a container to provide the dependency at runtime

Answer 2

You are creating a jar with dependencies, probably to run it standalone.

So if A needs B, and B has dependencies on its own, A probably needs those as well to run. It is therefore sensible to pack all the dependencies of B into the runnable jar.

If B has unnecessary dependencies, these should be removed from B.

If B has dependencies, that for some reason are not required when A uses B, you should add a proper exclusion to the dependency in the POM.