[maven] Errors in pom.xml with dependencies (Missing artifact...)

A friend has passed me a Maven project that I'm trying to run locally in my computer. All that I have done in Eclipse, I selected:

File -> Import -> Existing Maven Projects

After that, the project showed me 4 errors in my pom.xml (Missing artifact..):

I tried removing the content of .m2 folder and then in Eclipse I clicked on my project and chose "Run as" -> "Maven clean" and then "Run as" -> "Maven install". But I still have the same errors. I'm new with Spring so I dont know what else to do.

EDIT:

When I try to do: run as/ maven install, this is what my console says:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building DataLayer 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for javax.persistence:javax.persistence:jar:1.0.0 is missing, no     dependency information available
[WARNING] The POM for hibernate-core:hibernate-core:jar:4.2.1.Final is missing, no     dependency information available
[WARNING] The POM for hibernate-commons-annotations:hibernate-commons-annotations:jar:4.0.1.Final is missing, no dependency information available
[WARNING] The POM for jboss-logging:jboss-logging:jar:3.1.0.CR2 is missing, no dependency information available
[WARNING] The POM for jta:jta:jar:1.1 is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.065s
[INFO] Finished at: Wed Aug 07 11:41:45 VET 2013
[INFO] Final Memory: 4M/90M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project DataLayer: Could not resolve dependencies for     project SocialManager:DataLayer:jar:0.0.1-SNAPSHOT: The following artifacts could not be resolved: javax.persistence:javax.persistence:jar:1.0.0, hibernate-core:hibernate-core:jar:4.2.1.Final, hibernate-commons-annotations:hibernate-commons-annotations:jar:4.0.1.Final, jboss-logging:jboss-logging:jar:3.1.0.CR2, jta:jta:jar:1.1: Failure to find javax.persistence:javax.persistence:jar:1.0.0 in http://repository.jboss.org/nexus/content/groups/public/ was cached in the local repository, resolution will not be reattempted until the update interval of JBoss repository has elapsed or updates are forced -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.

EDIT2: This is my complete pom.xml: https://dl.dropboxusercontent.com/u/31349296/pom.xml It looks pretty awful when I try to paste the code here.

I somehow had this issue after I lost internet connection. I was able to fix it by updating the Maven indexes in Eclipse and then selecting my project and updating the Snapshots/releases.

SIMPLE..

First check with the closing tag of project. It should be placed after all the dependency tags are closed.This way I solved my error. --Sush happy coding :)

This is a very late answer,but this might help.I went to this link and searched for ojdbc8(I was trying to add jdbc oracle driver) When clicked on the result , a note was displayed like this:

I clicked the link in the note and the correct dependency was mentioned like below

I know it is an old question. But I hope my answer will help somebody. I had the same issue and I think the problem is that it cannot find those .jar files in your local repository. So what I did is I added the following code to my pom.xml and it worked.

<repositories>
  <repository>
      <id>spring-milestones</id>
      <name>Spring Milestones</name>
      <url>https://repo.spring.io/libs-milestone</url>
      <snapshots>
          <enabled>false</enabled>
      </snapshots>
  </repository>
</repositories>

It means maven is not able to download artifacts from repository. Following steps will help you:

1. Go to repository browser and check if artifact exist.
2. Check settings.xml to see if proper respository is specified.
3. Check proxy settings.