In the maven repository, there is a pom.xml corresponding to every jar. What is the use of that pom.xml.
How important is that pom.xml and will the execution work without that pom.xml ? Thanks in advance.
Each of those jars is a project (somewhere) that was built using Maven - hence the need for a pom. Also, the pom describes all the transitive dependencies for any jar that your project needs. Those files are important, and your project cannot build without them.
Related
I a maven rookie and am wondering how to get a binary jar file if it is not already in the repo. Specifically i'm in need of: jackson-dataformats-text-2.13.0.jar. Do I need to build it myself? I'm used to creating a project and marking a library as a dependency and seeing the jar downloaded into my .m2 cache but all i see in my cache is:
jchan#jchan-Z170N:~/.m2/repository/com/fasterxml/jackson/dataformat/jackson-dataformats-text/2.13.0$ ls
jackson-dataformats-text-2.13.0.jar.lastUpdated jackson-dataformats-text-2.13.0.pom.sha1
jackson-dataformats-text-2.13.0.pom _remote.repositories
Can someone advise how I am to get a built version of the jar from maven central?
We are still maintaining our ant build and I need the jar file for this. (i know i know, ancient stuff but team is not ready to port just yet).
parent pom don't contain jar file
This is the reason why no bundle link is present on the official public maven repository https://mvnrepository.com
The maven dependency is not a jar, is a parent. So the extension is: .pom which is just a plain pom.xml
Parent dependencies don't contain compiled class like .jar.
In your specific case, there are another dependencies who contains jars:
https://repo1.maven.org/maven2/com/fasterxml/jackson/dataformat/jackson-dataformat-yaml/2.13.0/
https://repo1.maven.org/maven2/com/fasterxml/jackson/dataformat/jackson-dataformat-xml/2.13.0/
advice
Check what classes do you need on your ant project and search if exist a jar (with the classes you need) on https://mvnrepository.com
Another option is to get all the dependencies from pom :
https://repo1.maven.org/maven2/com/fasterxml/jackson/dataformat/jackson-dataformats-text/2.9.0/jackson-dataformats-text-2.9.0.pom and download them into your ant project. In theory is the same of add the parent pom in a maven project
This question is about Maven. My project has spring-boot-starter-parent as its parent. Mvn Repository's link, shows that through all parent hierarchies, spring-boot-starter-parent has 273 dependencies in total.
However, when I run the goal dependency:copy-dependencies, I get only a handful of jars, and in particular, I notice that javassist is not one of the jars. Why aren't the jars for all 273 dependencies copied by dependency:copy-dependencies? Can Maven somehow tell if some of these dependencies are not needed by my project?
There are 273 managed dependencies in spring-boot-starter-parent. Managed dependencies are just there to give maven details about libraries your project uses when it needs it. They are not actually included in your project when it gets built. The dependencies included are those in your project's <dependencies> section and their transitive dependencies. Hence the difference you see.
I have a Java Maven project where I have some dependencies defined in the pom.xml file. Recently I decided to move from Junit to TestNG so I deleted the Junit dependency from my pom.xml and added the TestNG one.
I was expecting to see the Junit jar library disappear from the Maven Dependencies folder as a part of the process but that didn't happen. I can still see the jar file in the dependencies folder and it is still being used by my test cases.
I can see TestNG jar is there as well but it's not being used. I can change it manually of course but that wasn't my intention.
Am I doing something wrong are there any additional steps that I missed that will allow me to remove the old dependency?
The following applies for the global .m2 folder where maven dependencies can be downloaded and is common to your maven projects.
the .m2 folder will not clean by itself as those dependencies could be used in another project so its wrong assumption that replacing a dependency in a a pom file will automatically remove from your repo.
you can look at the depedency plugin and run the following
mvn dependency:purge-local-repository
or
mvn dependency:purge-local-repository -DreResolve=false
I have a web application which needs to be converted to Maven for building and deploying.
I was able to find dependency to add in pom for most of the jars but was not able to find dependency tag for few jar files.
How do I add these jars to my application so that my application compiles ?
Can I add these jars for Maven from web-inf/lib or some other location ?
You can install jars manually to your maven repository using the maven-install-plugin:
http://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
I've spent a lot of time and my head is blowing up already so I'll be very thankful for any help.
I'm migrating Netbeans Platform application from ant to maven, and so I'm changing all the jars in my version control repo to maven dependencies. I've found needed artifact in main maven repo and I've added it as a dependency with a help of Netbeans, but it's of type POM and was placed in Non-classpath Dependencies and I have no idea how to use it as it wasn't added to classpath etc…
Can someone explain what are these POM dependencies and how to use them?
Thank you in advance!!
EDIT
here is dependency definition in pom.xml
<dependency>
<groupId>com.kitfox.svg</groupId>
<artifactId>svg-salamander</artifactId>
<version>1.0</version>
<type>pom</type>
</dependency>
Adding a pom dependency only pulls down transitive dependencies, that is jar dependencies defined as dependencies in the pom. The pom does not get added on the classpath for obvious reasons, but the transitive dependencies reachable from pom will be added to classpath.
What you ideally need to do is have dependencies of type jar Default dependency type is jar and you can simply define dependencies without any type element in the dependency section.
If you have located the jar files you need in Maven Cental, then you simply need to provide groupId artifactId and version for each one of those in dependencies section.
Personally I cannot think of any case when one would need to add pom type dependency. I usually use pom packaging for parent module in a project (specify common project configuration like plugin versions, common dependencies, like log4j for example, repositories, properties etc.) and for utility package module (the one that assembles the project and does some other necessary things).
Judging from my experience (I did it several times), when migrating project from ant to maven you should take all the jar files that your project used to depend on and convert them into maven dependencies (groupId:artifactId:version). Most probably all of these dependencies will not have any <type> (e.g. be jars).