Maven dependecny is not available in eclipse java build path - java

I checked out an existing eclipse project from SVN. Then I converted it to Maven project.
The project is compile with Maven target clean install perfectly no problem. But the eclipse doesn't identify any dependency jar file. Basically it does not know the Maven repo path. It knows only JDK path. So all my java classes are with full of red lines.
Everything in this site and google I checked all fine. But why eclipse can not find the mvn repo?
eclipse version = JUNO Version: 4.2.2. ( I think this has inbuilt maven plugin)
Maven plugin detail = M2E - Maven Integration for Eclipse version - 1.4.0, Provider - Eclipse.org -m2e
UPDATE ======================
If I checkout the source code separately and import it as a maven project that way its working. But I want to know why if I checkout the code through Subclipse and convert it to maven project is not working?

Run
# use maven to control your eclipse .project and .classpath files, that is
mvn eclipse:clean
mvn eclipse:eclipse
and then restart your eclipse (or switch your workspace and then back).
Make sure you have the m2e plugin, - from here, you should read the Release Notes and add this to your update sites - "http://download.eclipse.org/releases/juno" and "http://download.eclipse.org/technology/m2e/releases".

In Eclipse, you can actually create an external tool Run> External Tools> External Tools Configurations. After this you can select your project that you want to setup and run this external tool.
or if you have maven plugin installed in eclipse, select your project right click Run As > Maven Build... (see below image). In Goals put "eclipse:eclipse" and click Run

Related

Eclipse and Maven-Wrapper

I try to build a project, which is using the Maven Wrapper. The build works fine on command line. There is also a plug-in for IntelliJ Idea. However, I haven't found any article, how to build such project with Eclipse.
Do you have an experience with project build by ./mvnw command instead of mvn in Eclipse, please?
As implied by the comment from LMC, the Java edition of Eclipse will come with the "m2e" plugin, which will automatically recognize a project with a pom.xml file as a Maven project, and it will automatically note the dependencies, download them, and compile your source code with those artifacts as dependencies.
That deals with dependencies and compilation. If your build is running unit tests with Surefire, or generating code with particular plugins, unless there is a specialized m2e connector for that plugin, Eclipse will not know to do that.
Inside Eclipse, if you need to run a Maven build, you don't need to care about "mvn" vs. "mvnw". Eclipse will have an embedded Maven installation.

Eclipse Maven Export Missing

I'm using Eclipse Kepler 64 bit. It already has m2e (maven plugin) pre-installed by default.
The import wizard has a Maven option but the export one doesn't:
I tried installing m2e from the Marketplace but it said that there was nothing to install.
How do I get it as export option as well?
As far as the M2E plugin is concerned, using Maven with Eclipse involve importing existing project, and making sure the pom.xml is complete (with the right "nature" added in it, in order to generate the right .project, as in this example)
See "Importing Maven Projects" in the Sonatype book.
But once the project is imported, it becomes a regular project (with additional maven capabilities), without any maven-specific export options.
All you need to "export" a maven project are the sources and the pom.xml: anyone can then run maven to get all the dependencies (from the pom.xml specifications).

How can I make eclipse make use of packages downloaded by maven?

When I use Maven compile, it will automatically download the depended java packages for me. Now, to debug the project, I import the project into Eclipse, but in Eclipse, the depended package is still missing. How can I get the packages? Or, can Eclipse use packages downloaded by Maven?
You don't really need to manually add all the dependencies downloaded by maven to the classpath in Eclipse. There is a maven-2-eclipse plugin which integrates maven with Eclipse. Using that plugin you can
import/create a project as Maven project or
convert an existing project into a maven project
Your Eclipse will automatically add all the downloaded dependencies on the class path everytime.
An alternative to the m2e eclipse maven plugin suggested by rocketboy is to use the maven eclipse plugin. This works from the command line (mvn eclipse:eclipse), and generates Eclipse settings for your project by downloading dependencies and putting them onto the Eclipse build path.

How to build and run Maven projects after importing into Eclipse IDE

I am learning building a Java project in Eclipse using Maven. I created a Java project HelloWorld from
“maven-archetype-quickstart” template in a folder D:/maven_projects. Then to convert the Maven project to support Eclipse IDE, I navigated into the project folder and issued the commands:
mvn eclipse:eclipse and mvn package .
Then I imported the project in Eclipse and did the necessary Eclipse configurations like setting the Maven local repository in Eclipse classpath. Now the project in D:/EclipseWorkspace folder. I ran the project successfully in Eclipse printing "helloworld".
Now if I want to go on develop the project and for that reason want to add new dependencies in pom.xml in Eclipse, then the new jars are not added in classpath when I run the project.
So my question is after importing a Maven project into Eclipse how can I add more and more dependencies in pom.xml, then build and run the project? What is the recommended and efficient way to do this?
I would recommend you don't use the m2eclipse command line tools (i.e. mvn eclipse:eclipse) and instead use the built-in Maven support, known as m2e.
Delete your project from Eclipse, then run mvn eclipse:clean on your project to remove the m2eclipse project data. Finally, with a modern version of Eclipse, just do "Import > Maven > Existing project into workspace..." and select your pom.xml.
M2e will automatically manage your dependencies and download them as required. It also supports Maven builds through a new "Run as Maven build..." interface. It's rather nifty.
1.Update project
Right Click on your project maven > update project
2.Build project
Right Click on your project again. run as > Maven build
If you have not created a “Run configuration” yet, it will open a new configuration with some auto filled values.
You can change the name. "Base directory" will be a auto filled value for you. Keep it as it is. Give maven command to ”Goals” fields.
i.e, “clean install” for building purpose
Click apply
Click run.
3.Run project on tomcat
Right Click on your project again. run as > Run-Configuration.
It will open Run-Configuration window for you.
Right Click on “Maven Build” from the right side column and Select “New”.
It will open a blank configuration for you.
Change the name as you want. For the base directory field you can choose values using 3 buttons(workspace,FileSystem,Variables). You can also copy and paste the auto generated value from previously created Run-configuration. Give the Goals as “tomcat:run”. Click apply. Click run.
If you want to get more clear idea with snapshots use the following link.
Build and Run Maven project in Eclipse
(I hope this answer will help someone come after the topic of the question)
Dependencies can be updated by using "Maven --> Update Project.." in Eclipse using m2e plugin, after pom.xml file modification.
Just install the m2e plugin for Eclipse. Then a new command in Eclipse's Import statement will be added called "Import existing maven projects".
answer 1
Right click on your project in eclipse
go to maven -> Update Project
answer 2
simply press Alt+F5
after updating your pom.xml. This will build your project again and download all jar files
Right Click on your project
Go to Maven>Update Project
Check the Force Update of Snapshots/Releases Checkbox
Click Ok
That's all. You can see progression of build in left below corner.
When you add dependency in pom.xml , do a maven clean , and then maven build , it will add the jars into you project.
You can search dependency artifacts at http://mvnrepository.com/
And if it doesn't add jars it should give you errors which will mean that it is not able to fetch the jar, that could be due to broken repository or connection problems.
Well sometimes if it is one or two jars, better download them and add to build path , but with a lot of dependencies use maven.
If you are getting this error :in cucumber Exception
Cucumber Exception: java.lang.ClassNotFoundException:
cucumber.io.ResourceLoader :
then add following jar file to your pom.xml
<dependency>
<groupId>info.cukes</groupId>
<artifactId>cucumber-core</artifactId>
<version>1.1.8</version>
</dependency>
Run the maven build once and should be gone

Errors after importing Maven project into Eclipse

I imported a Maven project into Eclipse. I was able to deploy it from the command line. In Eclipse it is full of red Xs. I have cleaned the project, updated the configuration and I ran the following command:
mvn -Declipse.workspace=<pathtoworksapce> eclipse:add-maven-repo
and I still have the same problem. The project is dependent on another project.
What I ended up doing was removing all of the projects in Eclipse, but not deleting the source files. Then instead of directly importing the code as Maven->Check out as Maven Projects with SCM, I selected Existing Maven Project and imported the code from my local machine. This got rid of the errors, but when I would right click on code and select "Open Declaration", I would get Error: Could not open the editor: The file does not exist" So I removed all projects again and this time I deleted all the ".project" files and repeated the import Existing Maven Project. So now there are no red Xs (dependency problems) and the lookup functionality within the code works.
Go to your master project and type the following :
mvn install
mvn eclipse:eclipse
After that, import your project. You can also install m2eclipse for better support. If you use gwt or any other framework which has a custom maven execution, you should also install plugins for those in Eclipse.

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