Develop Reference

How to add custom jar files into pom.xml

I am creating a maven project, in which I've two jar's for say x and y for now,which contains some helper classes for my project. I want to added these x and y jars to my project's pom.xml as dependency. As these two jar files are not available in maven repository. So I try to use these jar in my pom.xml with in repository tag.How to achieve this. I've searched in google and found one project , which is similar to my project.
when I build this it able to build application, I saw the jar file it created.But I couldn't create the same with new project. If I copy the entire pom.xml I'm able to build.What is dependency-reduced-pox.xml and how it will create. and in moven-local folder how it creates another pom.xml, which command is used to create these auto generated xml files Can any one help me to do this. Here are the screen shots of my maven project I got it .
here are other screen shot.

There are 3 ways:
A) Install your JARs to your local Maven repository and then use them in your project with provided groupId, artifactId and version: How to add local jar files to a Maven project? (this is quick & easy & pretty clean until you remove your local repository and delete your JARs accidentally).
B) Install Nexus or Artifactory (will will be then your remote Maven repository), set it up in your settings.xml, add those JARs to remove Maven repository and download them from there (this is much less error-prone, but in longer run it's worth it).
C) not recommended: Other response (btw. currently with most upvotes) from previously suggested resource: How to add local jar files to a Maven project? which contains systemPath tag. You shouldn't use it, because it will cause lots of headaches in the future (for example if you want to package your application to WAR), it's not the correct way, but it's possible.

Maven dependency for self placed jars in project level

I created the java class and converted into jar files. So, I want to use those jar files which I have placed in project level in some folder like "External Jar".
So I need to write a dependency in maven that when someone imports my project they should be able to run the program.

Basically you created your own jar and you want to publish this jar, so that when somebody else clone/use your project, this jar comes with (assuming that you have a maven project and dependency of your jar is included in pom.xml).
To achieve this, you need to publish your jar to maven , you can follow many of the online docs like http://kirang89.github.io/blog/2013/01/20/uploading-your-jar-to-maven-central/ on how to publish jar to maven central.
Edit:- As suggested by khmarbaise, please use official reference http://central.sonatype.org/ for central repository.

Add library into jar of project

My problem is with a project where I use the POI library. It's from apache and allows you to work with excel,word, ... .
I had to add some jar files to my library and it runs perfect.
The problem is when I put my JAR file somewhere else.
It gives me the errors it can't find the librarys.
Is there a way I can put my librarys into the 1 jar?
I already tried to add my lib folder as source package but that didn't help.

there is a Maven plugin for Eclipse called M2Eclipse, which will read a POM and construct a classpath out of jars it finds in the local repository and any remote repositories you've configured. It behaves largely like Maven does in terms of finding the latest version for a given jar (if you've specified a version range in your POM).
You can also have a look on this
http://fredpuls.com/site/softwaredevelopment/java/deploy/five_strategies_for_managing_j.htm

You want to make a 'shaded' or 'uber' jar, which has all of its dependencies included
There is a maven plugin for building a shaded jar.
https://maven.apache.org/plugins/maven-shade-plugin/

For me the fastest/ easiest solution was to just open my project in eclips and export is a runable JAR then it adds the librarys to the JAR.

NetBeans builds your application into the project's dist folder. There is also a readme file in it, that tells you, you should distribute the contents of that folder...
Edit
Remove the lib folder, that is shown on the second image, from your sources.

How to download Maven jars

I would like to have all the JAR files of Maven in my hard-drive to do some experiments. Is there any way to download all the jar files from Maven repository?
My operating system that i used is Windows 7.

It is not clear what you mean by "all the JAR files of Maven", the Maven central repository contains gigs of jar files. If you can explain further what you are trying to do then it will be easier to help.
If you have a maven project then you can run:
mvn clean install
from the directory where the pom.xml file is located. Maven will download all of the dependencies required by the project to your computer, the default location is the .m2 directory under your user directory.
Another option is to use the maven dependency plugin to download all of the dependencies of a given project to a location.

Use a repository manager like Nexus. http://nexus.sonatype.org/

or Apache Archiva too http://archiva.apache.org/ :-)
See http://docs.codehaus.org/display/MAVENUSER/Maven+Repository+Manager+Feature+Matrix

How to build project from maven pom file

I have a maven pom file for an open source project. This pom file has all the info like what other jars it depends on etc. I installed maven. Created a dir samprj and copied the pom file into that dir. Cd into that dir and ran mvn command without any arguments but I got bunch of errors. I am absolutely new to maven so I think I am missing something. I tried also from Eclipse ( Import project -- exisitng maven project) but that also does not work except eclipse creates a project that has just that file pom.xml. I expect something that first it will download the jar for the project and then download all dependent jars and config files but nothing there.
So given a pom file how do I build the project from it?

mvn install should get you going

I have a maven pom file for an open source project. This pom file has all the info like what other jars it depends on etc. I installed maven. Created a dir samprj and copied the pom file into that dir ...
It sounds like you only have the project's POM file. This is not sufficient. You need to checkout the complete source tree for the project. Having done that, change directory to the directory containing the POM file and run mvn install.
Also, don't copy the POM to a different directory. Maven expects to find all of the source files relative to the POM file location.
FOLLOW UP
Thanks for advice. I was not able to use the command mvn install as it gave errors.
Probably because you hadn't checked out the source.
I don't know how to check the source tree of the project ...
Use a subversion client (the svn command for example), or one of the Eclipse subversion plugins.
If this was a properly documented project, there would be clear instructions on what version control and build tools you needed, how to checkout the source code and how to build it.
... as I thought POM itself should have this information to automatically checkout if the source is not check out.
It doesn't necessarily, though in this particular case it does.
Anyway I was able use Eclipse to build the project without errors.
(Other readers can read #icyrock.com's answer for links to the m2eclipse plugin and documentation.)
The only problem is the dependent jars were downloaded but hidden deep paths in .m2 repository folder on my linux box.
But I would like these dependent jars to be relative to dir where POM file is.
Sorry, but that is not the way Maven works.
The ~/.m2/repository directory is a fundamental part of Maven. It is not a problem. It is a feature. (Don't fight it!)

If you want to open this within Eclipse, you need to install m2eclipse:
http://www.eclipse.org/m2e/
and then import the project as a Maven project as described here:
http://books.sonatype.com/m2eclipse-book/reference/creating-sect-importing-projects.html

Try out their getting started guide. It has a lot of good examples:
http://maven.apache.org/guides/getting-started/