Including the Jar of a Maven Project in another Maven Project does not work but including the Project in another Maven Project works

Question

I have 2 Projects namely Project_1 and Project_2. Both projects are Maven and I am using Netbeans.

I want to include the jar of Project_1 in Project_2 which I am doing like this.

The problem is when I include the jar I do not get any compile time error, however I get a NoClassDefFoundError exception at runtime.

When I include the Project_1 in Project_2 by performing the steps mentioned here. (The Open Project example). I do not get any errors. Neither runtime nor compile time.

Can you please explain me what am I missing here?

Update

Project_2 is deployed on a Server which is not in my local machine however Project_1 is in my local machine.

Inclusion of Project_1 into Project_2 as a project was done for testing in my local machine.

After doing the second option, it will also add an entry in pom.xml. Please look into it what it has added in tag — rizzz86, Jun 05 '12 at 20:50
@rizzz86 the scope and systemPath are missing if i include the project. — JHS, Jun 05 '12 at 20:57
So that means if you add the tag manually without scope and systemPath then it will also work ? — rizzz86, Jun 05 '12 at 21:00
See http://stackoverflow.com/questions/9201195/share-jar-of-the-module-with-another-team/9202409#9202409 — Mark O'Connor, Jun 05 '12 at 21:51

score 0 · Accepted Answer · edited May 23 '17 at 12:18

First of all, a good rule of thumb to adopt is never use the system scope and system path to pull in dependencies. In my experience there's always a better way :-)

If Project_2 depends on Project_1, then first install it's jar into the local repository:

   cd Project_1
   mvn clean install

Watch the output you'll discover the jar is placed somewhere under the following directory:

   $HOME/.m2/repository

Once this is done the jar will be available as a normal dependency to the second build

  cd Project_2
  mvn clean compile

The local repository ensures the projects are now decoupled from each other. Assuming you're using snapshot revisions of Project_1, the Project_2 build will always retrieve the latest revision built and tested.

Update

You should use a Maven repository manager to share jars between machines/teams. Recommendations are contained in the following answer:

Share jar of the module with another team

How to configure Maven to use a repository like Nexus is described in it's documentation.

As described in the deploy plugin documentation you'll need to add a distributionManagement section to your POM (detailing the repository URL) and then upload the project's jar to your repository as follows:

   cd Project_1
   mvn clean deploy

Thank you however there is issue. The `Project_1` is a project in my local computer and `Project_2` is a project deployed in a server. To include `Project_1`'s jar in `Project_2` i have to place the `Project_1`'s jar somewhere in the server and include it in `Project_2`. — JHS, Jun 05 '12 at 21:19
@Juniad Then you need to install a Maven repository manager and use this to deploy build output and pull dependencies. Highly recommended when you're sharing jars and will also improve the performance of your builds. See http://stackoverflow.com/questions/9201195/share-jar-of-the-module-with-another-team/9202409#9202409 — Mark O'Connor, Jun 05 '12 at 21:47

Including the Jar of a Maven Project in another Maven Project does not work but including the Project in another Maven Project works

1 Answers1

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