Can I add jars to Maven 2 build classpath without installing them?

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Maven 2 is driving me crazy during the experimentation / quick and dirty mock-up phase of development.

I have a pom.xml file that defines the dependencies for the web-app framework I want to use, and I can quickly generate starter projects from that file. However, sometimes I want to link to a 3rd party library that doesn't already have a pom.xml file defined, so rather than create the pom.xml file for the 3rd party lib by hand and install it, and add the dependency to my pom.xml, I would just like to tell Maven: "In addition to my defined dependencies, include any jars that are in /lib too."

It seems like this ought to be simple, but if it is, I am missing something.

Any pointers on how to do this are greatly appreciated. Short of that, if there is a simple way to point maven to a /lib directory and easily create a pom.xml with all the enclosed jars mapped to a single dependency which I could then name / install and link to in one fell swoop would also suffice.

24 Answers

For throw away code only

set scope == system and just make up a groupId, artifactId, and version

<dependency>
    <groupId>org.swinglabs</groupId>
    <artifactId>swingx</artifactId>
    <version>0.9.2</version>
    <scope>system</scope>
    <systemPath>${project.basedir}/lib/swingx-0.9.3.jar</systemPath>
</dependency>

Note: system dependencies are not copied into resulted jar/war
(see How to include system dependencies in war built using maven)

Note: When using the System scope (as mentioned on this page), Maven needs absolute paths.

If your jars are under your project's root, you'll want to prefix your systemPath values with ${basedir}.

This is how we add or install a local jar

    <dependency>
        <groupId>org.example</groupId>
        <artifactId>iamajar</artifactId>
        <version>1.0</version>
        <scope>system</scope>
        <systemPath>${project.basedir}/lib/iamajar.jar</systemPath>
    </dependency>

i gave some default groupId and artifactId because they are mandatory :)

You really ought to get a framework in place via a repository and identifying your dependencies up front. Using the system scope is a common mistake people use, because they "don't care about the dependency management." The trouble is that doing this you end up with a perverted maven build that will not show maven in a normal condition. You would be better off following an approach like this.

Maven install plugin has command line usage to install a jar into the local repository, POM is optional but you will have to specify the GroupId, ArtifactId, Version and Packaging (all the POM stuff).

To install the 3rd party jar which is not in maven repository use maven-install-plugin.

Below are steps:

  1. Download the jar file manually from the source (website)
  2. Create a folder and place your jar file in it
  3. Run the below command to install the 3rd party jar in your local maven repository

mvn install:install-file -Dfile= -DgroupId= -DartifactId= -Dversion= -Dpackaging=

Below is the e.g one I used it for simonsite log4j

mvn install:install-file -Dfile=/Users/athanka/git/MyProject/repo/log4j-rolling-appender.jar -DgroupId=uk.org.simonsite -DartifactId=log4j-rolling-appender -Dversion=20150607-2059 -Dpackaging=jar

  1. In the pom.xml include the dependency as below

      <dependency> 
            <groupId>uk.org.simonsite</groupId>
            <artifactId>log4j-rolling-appender</artifactId>
            <version>20150607-2059</version> 
      </dependency>
    
  2. Run the mvn clean install command to create your packaging

Below is the reference link:

https://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html

For those that didn't find a good answer here, this is what we are doing to get a jar with all the necessary dependencies in it. This answer (https://stackoverflow.com/a/7623805/1084306) mentions to use the Maven Assembly plugin but doesn't actually give an example in the answer. And if you don't read all the way to the end of the answer (it's pretty lengthy), you may miss it. Adding the below to your pom.xml will generate target/${PROJECT_NAME}-${VERSION}-jar-with-dependencies.jar

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.4.1</version>
            <configuration>
                <!-- get all project dependencies -->
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
                <!-- MainClass in mainfest make a executable jar -->
                <archive>
                  <manifest>
                    <mainClass>my.package.mainclass</mainClass>
                  </manifest>
                </archive>

            </configuration>
            <executions>
              <execution>
                <id>make-assembly</id>
                <!-- bind to the packaging phase -->
                <phase>package</phase> 
                <goals>
                    <goal>single</goal>
                </goals>
              </execution>
            </executions>
        </plugin>

This doesn't answer how to add them to your POM, and may be a no brainer, but would just adding the lib dir to your classpath work? I know that is what I do when I need an external jar that I don't want to add to my Maven repos.

Hope this helps.

The solution for scope='system' approach in Java:

public static void main(String[] args) {
        String filepath = "/Users/Downloads/lib/";
        try (Stream<Path> walk = Files.walk(Paths.get(filepath))) {

        List<String> result = walk.filter(Files::isRegularFile)
                .map(x -> x.toString()).collect(Collectors.toList());

                String indentation = "    ";
                for (String s : result) {
                    System.out.println(indentation + indentation + "<dependency>");
                    System.out.println(indentation + indentation + indentation + "<groupId>"
                            + s.replace(filepath, "").replace(".jar", "")
                            + "</groupId>");
                    System.out.println(indentation + indentation + indentation + "<artifactId>"
                            + s.replace(filepath, "").replace(".jar", "")
                            + "</artifactId>");
                    System.out.println(indentation + indentation + indentation + "<version>"
                            + s.replace(filepath, "").replace(".jar", "")
                            + "</version>");
                    System.out.println(indentation + indentation + indentation + "<scope>system</scope>");
                    System.out.println(indentation + indentation + indentation + "<systemPath>" + s + "</systemPath>");
                    System.out.println(indentation + indentation + "</dependency>");
                }

    } catch (IOException e) {
        e.printStackTrace();
    }
}
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