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Build Maven project with local dependencies

I downloaded old project, which based on Eclipse, Ant or something else, I don't know this build system (I use Maven\Gradle). Project sources was converted to Maven manually, but project had more jar libraries. They were imported in project with help of IDEA (Project Structure -> Modules -> Dependencies), but libraries defined only in .iml file.
When I tried to build project in .jar with help of Maven — Maven show errors, that it cannot find classes from libraries (but in sources all good). I found in Internet example, like in this code sample:
<dependency>
<groupId>example</groupId>
<artifactId>example</artifactId>
<version>examle</version>
<scope>system</scope>
<systemPath>${project.basedir}/libs/example.jar</systemPath>
</dependency>
But this don't help. Libraries are old too, and they created by old build tools, which don't write artifact id, group id and etc., so I don't know this information.
How I can write dependencies on local .jar libraries in pom.xml if I don't know information (group, artifact ids) about they?
UPD_0:
When I try to set only system path to library, I take this:

All you need is set correct path in the
<systemPath>${project.basedir}/libs/example.jar</systemPath>
group, artifact ids and version are user defined information. So you can define it as you wish.

Try to install this jar in ur local repository from command line / terminal like this. Then add the dependency with the package and version given by you in the command without scope as system
mvn install:install-file -Dfile=<path>/example.jar
-DgroupId=com.something
-DartifactId=example
-Dversion=<give some version>
-Dpackaging=jar
-DgeneratePom=true

How to add jar file dependency in pom.xml

I have an application that depends on 2 jar file :
OperatorInterface.jar
Operator.jar
I want to build my project using Maven structure. I've followed the Maven site tutorial to create the structure like so:
mvn -B archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DgroupId=source.app -DartifactId=project
I've put my source file FileProcess.java in E:\project\src\main\java\source\app.
FileProcess has dependency in 2 external .jar files but I don't know how to define this dependency in pom.xml.
Here is the content of the pom.xml so far:
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>source.app</groupId>
<artifactId>my-app</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>my-app</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Can anyone help me?

First thing you need to install your jars in your maven local repository. You can follow the official tutorial here:
https://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
During the installation you will have to choose your own artifactId, groupId and version. You can choose whatever value you want but remember them because you will need those to include your jars in the pom.
After that you can include them in your pom.xml adding these lines under the tag dependencies for each library to include:
<dependency>
<groupId>your_group_id</groupId>
<artifactId>your_artifact_id</artifactId>
<version>your_version</version>
</dependency>

In the case when the JARs in question are your own code rather than third-party, the best approach is to "mavenize" the projects that build them as well. After you do that, running mvn install on those projects will place them in your Maven local repository where they will be available to other local Maven projects who declare them as dependencies.

Avoid adding them to yourpom.xml file straight. When you add .jars using this process, they will automatically reflect in your pom.xml
Steps are -
1. Right click on your project in the file explorer in your eclipse.
2. Go to build Path option.
3. Select configure build path
4. Chose the Libraries tab in the window that appears.
5. Add your .jar file externally.
6. Click ok and come back to your project interface
Update your maven project by pressing Alt+F5 and restart eclipse. Your problem should be solved.

I would take the following route since this is for corporate use. This is the hard and ultimately portable way that sets you up for future Maven usage as it is intended to be done.
1) make those dependent jars Maven projects (because then you can easily version-manage them too using Maven)
2) use a local repository manager and deploy your own projects to it using Maven release management through either the mvn:release plugin, or use a build server such as Hudson to automate the release process with a simple button press which I can highly recommend setting up.
https://maven.apache.org/repository-management.html
http://maven.apache.org/maven-release/maven-release-plugin/
3) mvn:release the dependency jars to your local repository manager so they will be available for other Maven projects
4) you're actually done, when you have a local repository where your deploy your own snapshot and release artifacts to, then your maven build can find your own maven modules and include them in the application dependencies - if you don't forget to configure the repository in the project's pom of course. And your build server if you have one can find them too.
The easy/lazy route is as suggested to manually install the jars in your local .m2 folder where Maven caches dependencies that it downloads, but it is absolutely not a portable solution that will stand the test of time. It won't work when somebody else needs to work on this project until they too install the jars locally. Or if its only you, you need to redo it every time you checkout the project on another computer / as another user. Also you need to update the jars each and every time you make changes to them, everywhere the project is checked out. You may need to do specific setup steps to get it working in an IDE, should you inevitably choose to start to use one.
However if you are having a time-pressure problem, then I would certainly go ahead and do that as a temporary workaround solution to be able to get going.

Unknown small library (ex. webhdfs-java-client) in maven not found

I am trying to implement a little service in Scala using Maven to manage dependencies and I would like to add webhdfs-java-client that I have found at https://github.com/wdavidw/webhdfs-java-client
I have added to pom.xml following code:
<dependency>
<groupId>org.zxs</groupId>
<artifactId>webhdfs-java-client</artifactId>
<version>0.0.0</version>
</dependency>
It does not work, as I have expected. Does anyone could give me an advice if there exists some catalog of maven repositories (something like pip for Python)? And what can I possibly do if I'll not find this library in the catalog? Is it possible to somehow add it to maven manually?

In maven world you can install this dependency locally and resolution will be done via local cache (the one that usually resides in ~/.m2). Steps are as simple as mvn clean install in that repo. Having said this, it wouldn't resolve problem for your users (transitive dependencies, you know), which is why you likely need to publish that dependency somewhere (or ask library author whether it's published somewhere).
SBT, which is scala's de-facto build tool allows you to depend on other sbt flavored projects simply by referencing their git repository, but sadly, maven has no such feature.

Embed local jar files in maven project

I have some local jar files from a non-maven project which I wish to include in my maven-based eclipse project.
These jar files are undergoing a lot of change as me and my project buddy attempt to 'fix' them, so I'd prefer not to upload them to a repository to avoid making a maven version of this non-maven project if this is possible.
Of course, the jar files need to be embedded in the resulting deployment jar. We did this before using Ant which let us specify that those jar files should be included.
How do you do the same thing in maven? Take into consideration that we do have maven dependencies too which all work fine and aren't required in the deployment. Some answers I've seen don't allow for this requirement.
Here's one of my attempts - the problem is that the jar does not get embedded:
<dependency>
<groupId>se.krka.kahlua</groupId>
<artifactId>kahlua-core</artifactId>
<version>5.1_2.1.0</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/kahlua-5.1_2.1.0-core.jar</systemPath>
</dependency>

System paths are a very bad idea. When anybody else checks out your projects, he cannot build it anymore. (I always see such crap in many companies). The right solution would be to install the jar into the local repository:
$ mvn install:install-file -Dfile=[JAR NAME] -DgroupId=[GROUPID OF
JAR] -DartifactId=[ARTIFACT OF JAR] -Dversion=[VERSION OF JAR]
-Dpackaging=jar
In your project, you just add the dependency as usual after you installed the jar into the local repository.
<dependency>
<groupId>[GROUPID OF JAR]</groupId>
<artifactId>[ARTIFACT OF JAR]</artifactId>
<version>[VERSION OF JAR]</version>
</dependency>

You can use maven-install-plugin to install kahlua-5.1_2.1.0-core.jar into the local repository then this dependency will behave as any other, see http://maven.apache.org/plugins/maven-install-plugin/usage.html. Or make a remote repository in a location shared with your buddy and let him upload his jar there with maven-deploy-plugin:deploy-file (http://maven.apache.org/guides/mini/guide-3rd-party-jars-remote.html) each time he changes it and add this repository to your pom. You can use SNAPSHOT version if this jar changes often

Add a dependency in Maven

How do I take a jar file that I have and add it to the dependency system in maven 2? I will be the maintainer of this dependency and my code needs this jar in the class path so that it will compile.

You'll have to do this in two steps:
1. Give your JAR a groupId, artifactId and version and add it to your repository.
If you don't have an internal repository, and you're just trying to add your JAR to your local repository, you can install it as follows, using any arbitrary groupId/artifactIds:
mvn install:install-file -DgroupId=com.stackoverflow... -DartifactId=yourartifactid... -Dversion=1.0 -Dpackaging=jar -Dfile=/path/to/jarfile
You can also deploy it to your internal repository if you have one, and want to make this available to other developers in your organization. I just use my repository's web based interface to add artifacts, but you should be able to accomplish the same thing using mvn deploy:deploy-file ....
2. Update dependent projects to reference this JAR.
Then update the dependency in the pom.xml of the projects that use the JAR by adding the following to the element:
<dependencies>
...
<dependency>
<groupId>com.stackoverflow...</groupId>
<artifactId>artifactId...</artifactId>
<version>1.0</version>
</dependency>
...
</dependencies>

You can also specify a dependency not in a maven repository. Could be usefull when no central maven repository for your team exist or if you have a CI server
<dependency>
<groupId>com.stackoverflow</groupId>
<artifactId>commons-utils</artifactId>
<version>1.3</version>
<scope>system</scope>
<systemPath>${basedir}/lib/commons-utils.jar</systemPath>
</dependency>

Actually, on investigating this, I think all these answers are incorrect. Your question is misleading because of our level of understanding of maven. And I say our because I'm just getting introduced to maven.
In Eclipse, when you want to add a jar file to your project, normally you download the jar manually and then drop it into the lib directory. With maven, you don't do it this way. Here's what you do:
Go to mvnrepository
Search for the library you want to add
Copy the dependency statement into your pom.xml
rebuild via mvn
Now, maven will connect and download the jar along with the list of dependencies, and automatically resolve any additional dependencies that jar may have had. So if the jar also needed commons-logging, that will be downloaded as well.

I'd do this:
add the dependency as you like in your pom:
<dependency>
<groupId>com.stackoverflow...</groupId>
<artifactId>artifactId...</artifactId>
<version>1.0</version>
</dependency>
run mvn install it will try to download the jar and fail. On the process, it
will give you the complete command of installing the jar with the error message. Copy that command and run it! easy huh?!

I'll assume that you're asking how to push a dependency out to a "well-known repository," and not simply asking how to update your POM.
If yes, then this is what you want to read.
And for anyone looking to set up an internal repository server, look here (half of the problem with using Maven 2 is finding the docs)