I have an environment variable called $MYCLASSPATH that contains a set of directories that contain JARS. An example of my environment variable could be the following:
/project1/jars/:/project2/jars:/project3/jars
I also have a maven project that contains some external dependencies that are defined in the pom.xml. However, I want to include all the directories listed in the above environment variable in Maven since some JARS are required for the compilation.
Without Maven I could do this:
javac -cp "$MYCLASSPATH" path/to/my/java_file
How can I add all these directories to Maven?
As an addition to crowne's answer, once you know the coordinates the external dependencies would have to be added to your local maven repository using mvn install:install-file
For example
mvn install:install-file -Dfile=path_to_your_jar -DgroupId=X -DartifactId=X -Dversion=X -Dpackaging=jar
Your POM can then contain these dependencies in the same way normal dependencies are declared eg.
<dependency>
<groupId>X</groupId>
<artifactId>X</artifactId>
<version>X</version>
</dependency>
Each jar should be identified by a specific set of maven coordinates
https://maven.apache.org/pom.html#Maven_Coordinates
This lets us know which version of the jar the project is dependent on and where to get it from in the maven repository.
It also allows the project to be built correctly from another computer with a different set of environment variables.
So you should define your dependencies in your pom using the correct maven coordinates.
Related
I have a maven project with some dependencies, and the resulting artifact contains the dependencies as .jar files inside.
I could check the effective pom, but that does not show the actual .jar filenames / classes for the dependencies.
Is there any way to print dependency .jar names?
Is the name always ${artifactId}-${version}.jar?
You can view the dependencies used in a Maven build with the Maven Dependency Plugin. To view the dependencies as a list, use:
mvn dependency:list
A better representation might be the dependency tree, though, as it clearly shows relationships between imported dependency POMs and transitive dependencies:
mvn dependency:tree
If you want to see a raw list of the JARs bundled together in your build, you can also use the dependency plugin's copy-dependencies goal:
$ mvn dependency:copy-dependencies -DoutputDirectory="\${project.builddir}/bundled-jars"
$ ls -1 target/bundled-jars
Note that the destination is in quotes with the $ escaped so that it can use the Maven property without invoking shell substitution. You could also just write -DoutputDirectory=target/bundled-jars.
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
I would need to execute a specific Maven plugin from command line. For example, in the following I execute a specific version of Maven Surefire Plugin to test Java projects:
mvn org.apache.maven.plugins:maven-surefire-plugin:2.19-SNAPSHOT:test
However, the above assumes to find the surefire plugin 2.19 in the default Maven repository path. Now, my question is, if I want to use the plugin with a specific path (not Maven default one), what should I do using the command line? I would expect something like the following, without modifying pom.xml:
mvn /path/to/some/jar/version/org.apache.maven.plugins:maven-surefire-plugin:2.19-SNAPSHOT:test
or more generally, for the following invocation
mvn groupId:artifactId:version:goal
I would need somewhere to specify a customized path to execute its goal
mvn /some/path/to/groupId:artifactId:version:goal
On the other hand, please let me know if this is not even supported by Maven.
This is not how it works. Maven will always look-up artifacts inside your local repository. And if it can't find it in your local repository, it will try to download it from configured remote repositories.
As such, you don't specify a path to a plugin. You specify a path to a local repository, where that plugin is installed. In this local repository will be installed all the dependencies of the plugin you're trying to invoke. This also means that you cannot have a JAR to a plugin "sitting around" anywhere; it needs to be located inside a correct repository tree directory. With a local repository of /my/local/repo, the artifacts of the plugin groupId:artifactId:version must be located in /my/local/repo/groupId/artifactId/version and be named artifactId-version.jar (and .pom). In the same say, the location of the dependencies of that plugin must follow that directory structure.
By default, the local repository is located inside ~/.m2/repository. But you can change that by:
Specifying the maven.repo.local system property on the command line, for example with mvn -Dmaven.repo.local=/path/to/local/repo groupId:artifactId:version:goal;
Use a custom settings.xml and tell Maven to use it with the -s command line option. It would contain:
<settings>
<localRepository>/path/to/local/repo</localRepository>
</settings>
and be used with mvn -s /path/to/settings.xml groupId:artifactId:version:goal
There is a jar file lets say "abc.jar" which maven dependency does not exist(ie created a jar by using java command of own classes). I want to add this jar as maven dependency so that at build time it will automatically copy that jar in lib folder as like other maven dependency. how i will do. please help .
Add it as a dependency with a system scope. See the docs here.
However, rather than adding it as a system dependency it might be better to mavenize the jar itself, then you can build and install it into your dependency management system.
Also, see this question: Can I add jars to maven 2 build classpath without installing them?
You can use the systemPath attribute in the dependency tag in the POM file of your project.
In your pom.xml, use the following snippet corresponding to abc.jar:
<dependencies>
<!-- Other dependencies -->
<dependency>
<groupId>abc</groupId>
<artifactId>x</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>{path_to_abc.jar}</systemPath>
</dependency>
</dependencies>
The scope parameter corresponding to this artifact must be set to system, for the artifact to be picked up from the specified systemPath.
Hope this helps!
A normal maven dependency is always resolved by looking into a repository. So you must put your JAR file into a repository.
You could install your JAR into your local repository. Have a look at the install plugin. The install-file goal is your friend.
If other developers also need this JAR (because they are working with the same project), they either need to install it locally too, or - better - you deploy the JAR to a remote repository. Have a look at the deploy plugin. Here the deploy-file goal is your friend. For deploying artifacts, you need a repository manager like Nexus or Artifactory.
However, a dependency could also have the system scope (look at the other answers).
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