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Maven connection to IDE

I am using Maven to use Postrgres SQL driver. Besides I am using InteliJ IDEA Ultimatre Edition, and, as I understood, Maven is included in Ultimate version initially. Correct me - all I need, is to set dependencies, and connect PostrgeSQL to Java. I am not oblige to Download Maven (except required Dependecie of course, I mean Maven as framework)? Thanks a lot!

When you are creating a new project, choose Maven. After the project is created, you will receive an empty Maven project structure with the pom.xml and a script mvnw of Maven Wrapper, which you can use (instead of mvn) to build your app.
Just add dependencies to the pom.xml and build.
The Maven Wrapper will do the work for you - download Maven into the project subdirectory and use it.

Add project repo for an edited jar in Eclipse Maven project

I have a legacy project that I'd like to convert to a Maven project for dependency management.
The problem is, that I have one jar (fop-1.1.jar) that I had to edit. It differs from the one that is publicly available and I only have it locally. But I need it this way.
What I tried to do, following several similar how-to's, it to create a fake Maven repo inside the project (local repo is no good, because several people work on that project and the solution has to be self-contained on Git) and reference this repo from the pom.xml. Sounds like the way to go for me, but it doesn't work. Eclipse show the project repo grayed-out :(
What am I missing?
BTW: this is what I tried to follow: https://devcenter.heroku.com/articles/local-maven-dependencies

Let me suggest another way: When we need to "edit" a jar, we give it a special version number like 1.1-edited instead of 1.1.. Then we can easily upload it to our normal Maven repository and use it. Maven even makes sure that you do not accidentally load both versions in the same project because the edit is only in the version number.

I guess what you need is a private maven server(I guess it exists), and then execute command to deploy jar( before deploy, check your account has privileges)
mvn deploy:deploy-file -Dfile=${jarFilePath} -DgroupId=${groupID} -DartifactId=${artifactId} -Dversion=${version} -Durl=${privateServerURL} -Dpackaging=jar -DrepositoryId=${privateServerURLInYourMavenSettings.xml}
,
after deploy successfully, add maven dependency
<dependency>
<groupId>${groupID}</groupId>
<artifactId>${artifactId}</artifactId>
<version>${version}</version>
</dependency>

Add Maven repo into class path

I have a Maven repo which contains all of the dependencies needed for a Java project.
How do I add the maven repo into the classpath environment variable so it can be access via the console?
Working with a project that has a bash script to setup the development environment. This also runs some Java code but is can not see any for the dependencies of the project.

You can configure either the setting.xml at user level (${user.home}/.m2/settings.xml) or the global level configuration (${maven.home}/conf/settings.xml) by specifying the localRepository element to define the local repository path. Setting the environment variable MY_M2_REPO, before running maven, will effectively define the local repository path.
<localRepository>${env.MY_M2_REPO}</localRepository>
Alternatively, you can use the argument maven.repo.local to specify the location of your local repository when running maven.
mvn clean package -Dmaven.repo.local=/home/user/maven_repo

maven- not downloading new added dependency in pom.xml file

I need new third party jar for reading csv in maven based project. So, I did entry in pom.xml for same as below.
<dependency>
<groupId>net.sf.opencsv</groupId>
<artifactId>opencsv</artifactId>
<version>2.0</version>
</dependency>
But when I run mvn install or mvn package command, It does not download newly added dependency and just build project and generate war.
I am trying to get the issue! Please share solution if anybody face this earlier!
Regards

Try running a forced update:
mvn clean install -U
The -U (uppercase U) forces maven to look at all dependencies and try to update them.

If the dependency is defined in a <dependencies> block that is within a <dependencyManagement> block, adding it without the version number to a <dependencies> block that is outside <dependencyManagement> may fix the problem.
This is because the purpose of <dependencyManagement> block is to manage dependency versions, and not to install the dependencies. See this other article: Differences between dependencyManagement and dependencies in Maven

I resolved this issue by following steps:
1). Remove concerned jar from local /m2 folder.
2). Run mvn eclipse:eclipse command
3). And last run: mvn clean install
Now I am looking for concerned jar in my project class path!

If you are using IntelliJ Idea as your editor then simply follow 3 simple steps:
Right click on your project
Select Maven (last option probably)
Select "Reload project"
And that's it, IntelliJ Idea will download the dependencies and now you can proceed further.

Try:
Menu -> Project -> Clean -> Select the project
Right Click on the project -> Maven -> Maven clean
Right Click on the project -> Maven -> Maven install
Happened to me and it has fixed my problem. Hope it helps you.

I deleted .m2 folder and then from eclipse ran maven install then took maven update project. It resolved my issue and jar file got downloaded.

You can usually resolve these errors by updating Maven dependencies as follows:
Right-click on your top-level project (not on the pom.xml file) in the Project Explorer view.
From the menu, choose Maven > Update project
Make sure ForceUpdate of Snapshots/Releases is checked, and click OK.
You'll see a progress indicator in the lower-right-hand corner of the application window. When the update completes, you should be able to generate code normally, and the error markers should disappear.

In IntelliJ
Right-click on your root folder of the project in the Project Explorer view. From the menu, choose Maven > Reload project.
After that, your new dependencies will be downloaded. Then you should be able to generate code normally, and all the error markers will disappear.

Error opening Maven POM file dependency hierarchy in Eclipse - "Project read error"

When I open a POM file and click on the "Dependency Hierarchy" tab at the bottom, it gives me the error, "Project read error". It works with other projects in the same workspace, just not with this one. Any ideas?
EDIT
In response to #Yhn's answer.
Running the compile and package phases outside of Eclipse from the command-line work as expected. It compiles the application and builds the final WAR file.
Eclipse is indeed pointing to the default location of the Maven settings.xml file, so it should be aware of the custom repositories that are defined in it (my company has its own Maven repository).
I can open and edit the POM file from Eclipse, so it must have read/write permissions to the file.
The project is not configured in Eclipse as a Maven project, so I cannot run the package phase from Eclipse (I can only run it from the command-line).
I wonder if it has anything to do with the fact that I was having trouble building the project with Maven 3 because apparently some of the transitive dependencies are configured for Maven 1, which Maven 3 does not support (this is my theory anyway, based on some of the error messages). I can build the project with Maven 2, but I still get messages such as the following:
Downloading: http://dist.codehaus.org/mule/dependencies/maven2/org/codehaus/xfie/bcprov-jdk14/133/bcprov-jdk14-133.pom
[INFO] Unable to find resource 'org.codehaus.xfire:bcprov-jdk14:pom:133' in repsitory mule (http://dist.codehaus.org/mule/dependencies/maven2)
It must be able to find these dependences however, because it downloaded the JARs just fine and can build the application. It seems like the problem is that the dependencies don't have POM files associated with them, which is maybe why they cannot be used with Maven 3. This might also be why I cannot view the Dependency Hierarchy in Eclipse.
EDIT 2
I converted the project to a Maven project by going to "Configure > Convert to Maven Project". When I open the POM file, I see the error:
ArtifactDescriptorException: Failed to read artifact descriptor for woodstox:wst (Click for 140 more)
(woodstox:wst is another transitive dependency of the project). An error appears in the "Markers" view for seemingly every depedency and transitive dependency in my project. However, I can successfully build the project by doing a "Run As > Maven build". (Edit: This might be because this project has no Java source code, but the JARs of the dependencies correctly appear in the final WAR.) The Dependency Hierarchy still gives the same error--"Project read error".
About the "Unable to find resource" messages--but this only appears for a handful of transitive dependencies. The project has many more transitive dependencies, but these messages do not appear for them. It seems like, because the dependencies do not have POM files, that Maven tries to search for them every time the project is built. Is this normal not to have POMs??
How might I go about getting a repo manager? Is this something that would have to be installed on the company's Maven repository or can you install it on your own workstation?

I had this problem with some non-maven jars that I needed to include in my maven project. I put the jars in my local repository using this maven command:
mvn install:install-file -Dfile=/test/gov.nist.xccdf-1.2.jar -DgroupId=gov.nist -DartifactId=xccdf -Dpackaging=jar -Dversion=1.2
Then I referred to them as dependencies in my pom.xml:
<dependency>
<groupId>gov.nist</groupId>
<artifactId>xccdf</artifactId>
<version>1.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
This worked fine for a while, but I must have upgraded something in eclipse, and I started getting the error you describe.
The fix is to take them out of the local repository, and redo the install-file asking maven to generate a pom for you:
mvn -DgeneratePom=true install:install-file -Dfile=/test/gov.nist.xccdf-1.2.jar -DgroupId=gov.nist -DartifactId=xccdf -Dpackaging=jar -Dversion=1.2
The command will cause a pom to be generated in the same directory (within your local repo) where the jar is placed.
In recent versions of eclipse maven support, the maven build is still done with maven 2 (if you right-click your pom.xml, choose run as mvn package for example). The dependency analysis is now done with an embedded maven 3 plugin, which doesn't like a dependency that has no pom.xml.

I had the same problem. If you made your project a maven project, you should run:
Right Mouse Click on project | Maven | Update Dependencies or
Right Mouse Click on project | Maven | Update Project Configuration
That worked for me.

Given the information through the comments:
mvn compile/mvn package work through console (I'm assuming outside of eclipse). Based on that, the POM file should be correct and dependencies can be resolved.
However; it could be that eclipse's settings aren't correct. For example, if eclipse has some own maven properties (instead of the default ~/.m2/settings.xml file); I can imagine it to fail resolving dependencies configured in the settings.xml used by maven itself. The settings for this should be in the Eclipse Preferences # Maven > User Settings.
Also make sure that Eclipse can actually read the file (not locked, correct rights, etc).
Should this seem to be correct; can you try to run the mvn goal compile from eclipse? You can do this by right-clicking the project and selecting run as > maven package. That way it should run maven with the same settings as eclipse is using, and might show any additional errors in it's configuration.
--
In response to additional information:
Basically it tells you - when using Maven 2 - that it can't find a dependency resource (in this case bcprov-jdk14) in the given repository (codehaus/mule). When I search that maven module (bcprov-jdk14) I find it in the Maven central repo (through our local nexus) # repo1.maven.org/maven2. Maybe that causes the error you're getting with Maven2?
And as the Maven 3 doc says; for Maven 1.x repo's; you should proxy them through a repo manager that can serve it to you as a maven 2 repository (I believe we do that here too for some repo's through Sonatype Nexus OSS)
ps.: Enabling maven dependency management in eclipse should be enough to be able to use maven run targets; if you would want to test it.
--
Sound like it can be multiple problems... given that the normal maven build works fine, one would think that maven can at least get the artifacts it depends upon and their dependencies... Yet, eclipse doesn't seem to be able to.
Double check if your Eclipse internet connection settings are correct? Since you were talking about a company repo, I'm assuming there will probably also be a proxy (I had to set up my Eclipse to use that one too; though for plugins (see next point)).
Another possibility, from experience, can be a rule-based proxy block on *.pom url requests (our proxy here blocks that to force usage of the local repo manager, how evil and annoying that is :(). You might want to try and open the .pom file it tries to download manually in your browser to see if this is the case (I can't, for example...).
To get the repo set up, you would probably have to ask the one responsible for the repository to add it as a maven2 proxy.
At the very least, it seems Eclipse is having issues getting the dependency poms (which are needed to build the dependency tree) from the internet. You could always try to ask some ICT crew (if they are capable enough...) about it at your company, maybe they have some useful hints.

right click on the project, Maven->Update Project->Tick "Force Update of Snapshots/Releases"

I had the same problem when I added a new dependency to pom.xml without network connection. After this, I had so many problems such as "Missing artifacts", "Missing Descriptor", or "Project Read error". I solved this
delete the bad dependency just added from local repository.
rebuild local index.
re-add the dependency

<properties>
<!-- ********************** -->
<!-- Plugin's properties -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.7</java.version>
</properties>
this pom setting worked for me

Usually this happens if there is a typo in the pom that Maven cannot understand and then it throws Project read error. Like in my case I copied a maven dependency snippet and I by passed the version. Instead of typing the actual version # it was getting it dynamically ${asciidoctorj.version} and my pom didn't have this in the properties section. So I got this error. Once I removed that and put a version number it started working.

I had this after copying a local repository folder from another machine. The fix was to go into the repository folder I copied and delete
_remote.repositories along with the 'LastUpdated' files then refresh the Maven dependencies in Eclipse (Alt+F5)

I faced same situation today. In my case it's caused by dependency name in wrong case. E.g.
Project A -> Project B -> Project C
In project B's pm file, I mistakenly specified the dependency artifacts name with "c" in stead of "C".
As in mac os, the files system is case insensitive. so I can build it in command line without detecting this mistake.
In Eclipse it breaks, but it provides very bad error message. In the error list, it says "dependency problem", but the name of dependency is empty. It also can't identify which line in the POM causes the problem.
When try to open "Effective POM" in POM viewer, it will show project read error. In the pop up error dialog box, it will show:
Could not read maven project
java.nio.channels.OverlappingFileLockException
All the messages are useless and misleading.
I finally detected this problem by submit to Jenkins CI after wasted hours of time.

I did maven clean install and the errors were gone

I faced the same issue of "Project read error" while clicking on "Dependency Hierarchy" tab. In my project I had a parent pom and child pom.
Parent pom had a property <appVersion>4.5<appVersion> that was being used in child pom
<version>${appVersion}<version>.
I selected the main project, right click and choose run as maven clean. The console display showed warning that version is using expression but should be a constant. Replacing ${appVersion} with constant value of 4.5 fixed the issue.