I'm converting an ant backed Netbeans project into an Maven project. I've got most of the third party libraries set up in the POM, however now I've run into problems with setting up the local dependencies.
With the previous Netbeans way of doing things, it just added a project reference [with links to the source and jar location, rebuilt the dependency if the depedency's source had been changed and hadn't been compiled]. However I'm not sure how to setup up Maven to emulate this behavior. Is it possible?
Example:
Projects/SharedLibrariesResource [Ant based project]
Projects/WebSite [this is a maven based project]
Projects/Client
In this example the website and client projects don't connect to each other, but they do share the SharedLibrariesResource. Website should compile to produce a War with links to the SharedLibrariesResource
The way I understand the question, the Website maven project depends on the ant SharedLibrariesResource project. When Website is built, it should include the SharedLibrariesResource artifacts. The assumption is SharedLibrariesResources produces a jar artifact.
One way to achieve this is to
install SharedLibrariesResource to your local maven repository each time ant builds it
specify this as a dependency in Website pom.
We can use maven ant tasks to achieve the first.
Related
Background
My Eclipse RCP application is built using Tycho. It consists of multiple components (in the form of OSGi bundles/Eclipse plug-ins). One of these component contains the product file and materializes the product.
There is a reactor POM at the application root, which builds all components in order, but I also want to build other components independently (using mvn deploy) .
Building such a single component works as follows:
Retrieve the latest versions of all the component's dependencies from our company (p2) repository.
Build the component.
Deploy the component to our company repository to be used as a dependency for other components itself.
Note: Our repository is a normal maven2 repository hosted on a Nexus, whose RCP artifacts are automatically mapped to a p2 repository format as well. This way, Tycho can use the p2 repository format to find dependencies, while the standard Maven deployment can be used. This works fine.
Note: My parent POM makes sure that we look for dependencies at the p2 repository URL. The deployment URL is the default maven2 format location of the repository. This works fine.
Problem
When building such a single component through the command-line (mvn deploy), Maven looks for intra-project dependencies in the p2 repository and they are correctly resolved (i.e. latest version is automatically downloaded and used in build).
However, when developing in Eclipse, the IDE cannot resolve them. The manifest files gives an error at each of my intra-project dependencies that they cannot be resolved.
Question
My question is: How can I make the Eclipse IDE look for dependencies (and new versions of dependencies) in either:
My local p2 repository (~/.m2/repository/p2/osgi/bundles)
My company p2 repository (nexus.mycompany.com/myproduct-snapshots/.meta/p2)
Ideally, it would look for them every time and fetch the latest version if a newer version is available.
If it does not use the p2 repository URLs in the POM, how should I configure Eclipse?
Example
Consider an eclipse plug-in com.mycompany.myproduct.fancy, which depends on another eclipse plug-in com.mycompany.myproduct.core.
Both also have a POM (configured for Tycho use), which (through their parent POM) have my Nexus repositories configured correctly: maven2 repository URL for deployment and p2 repository URL to look for dependencies.
First I deploy the core plug-in to my maven repository (using the default mvn deploy). The Nexus repository will provide this deployed plug-in in both maven and p2 format.
When I build the fancy component through the command line (using mvn install), the (earlier deployed) core component is found and downloaded automatically.
project/com.mycompany.myproduct.fancy$ mvn clean install
<searches in p2 repository, download core>
<builds fancy>
<SUCCESS>
When I open a new Eclipse workspace and open the fancy component, its Manifest (which contains its dependencies) gives the following error:
Bundle 'com.mycompany.myproduct.core' cannot be resolved.
My question is: how can I develop the fancy component in the Eclipse IDE without the need to open core as project in Eclipse.
Speculation
This is some speculation from my side. Please correct me if I'm wrong and any other solution to the actual problem is also welcome!
I know the m2e plug-in of the Eclipse IDE currently maps Maven POMs to Eclipse concepts (using m2e connectors). I have installed the dedicated Tycho connectors. For example, the mvn compile step is actually performed by the Eclipse JDT compiler.
I also know that when a complete Tycho product is started in Eclipse, it is run in the Eclipse PDE environment. For example, I need to a specify a target platform in my Run configuration.
I know I can open all components in my Eclipse workspace. This would solve the problem, but is not feasible as I have many components and this would break independent component development.
I assume the Eclipse m2e mapping and/or the PDE build environment is not smart enough to fetch (latest) dependencies automatically at build time. Please correct me if I'm wrong. :)
Therefore, I assume I need to specify the target platform at build time too. I have taken a look at Window > Preferences > Plug-in Development > Target Platform. I can add our p2 repository to the Target Platform, which solves the problem. However this gives many problems:
I need a feature containing all components for this to work. Only features can be added.
Every time I deploy a new build of a single component, I would have to rebuild the complete feature (to create a new feature version on our p2 repository).
Every time I update a component and build the feature, I would have to manually change the Target Platform.
If the above is all correct, I speculate I need an m2e connector (or a different one from the current one) that actually checks the p2 repositories specified in the POM when resolving the OSGi dependencies and automatically adds those to the target platform.
As indicated by Nick Wilson, you will need to install the m2e Tycho Configurator, which basically "links up" Eclipse and Tycho (i.e., makes Tycho available in Eclipse).
You should've been pointed towards it after having installed m2e, but you can also install it manually:
Go to Window > Preferences > Maven > Discovery.
Click the "Open Catalog" button. This will open the "m2e Marketplace" window.
Search for "tycho", this should give you the "Tycho Configurator" as sole search result.
Click "Finish", you're done.
I've had this issue as well, and it isn't simple to find the solution, so I hope this helps!
The "most automated" way to configure your target platform in Eclipse is to use a target file. That file can be checked in with your sources, so every developer only needs to open the file and click on "Set as Target Platform" to activate it. AFAIK there is no m2e connector or Eclipse plug-in which does that automatically.
Given your development process, setting up this target file is a little more tricky. Since you don't have a feature which contains the latest version of all your bundles, you need to include the bundles directly in the target file. This is not possible via the rich editor, but can be done with a text editor:
Create a target definition file, add your p2 repository, and select any feature from that p2 repository. Save the file.
Open the target file in a text editor, remove the <unit> entry for the feature you added.
Instead, add an entry for each of your bundles:
<unit id="a.bundle.symbolic.name" version="0.0.0"/>
This target file then contains the latest version of each of the listed bundles. To see the content, open the file with the "Target Editor" again and switch to the "Content" tab. This file can now be used by all developers.
Note: When a new version of one of the bundles is deployed to Nexus, the developers will only see that new version if they open the target file and choose "Set as Target Platform" again.
I thought I understood Maven as I've worked on a few projects using it, but I seem to be having trouble creating my own project with it, so can someone correct me wherever I may be wrong?
Assuming I create a new Maven project (we'll say I did it through Eclipse or IntelliJ):
If I add a dependency to my POM file, assuming I add a public repository where that dependency can be found, shouldn't the IDE download the specified JAR and make it so that it is recognized when I use it in my code? Currently, my projects do not recognize any classes that should be found in JARs via my POM dependencies.
Assuming #1 does work, how can I determine via maven which transient dependencies I have? For example, I'm using classes from Pentaho Data Integration, and some of the plugins for it reference things like org.mozilla.javascript.*. Could maven automatically tell me that without me having to run the code, see it fail, and manually fix the dependency? There will be hundreds of those instances here, so manual fixing really isn't viable.
Here are my IntelliJ two cents:
1 - Adding a dependency in pom.xml of your project
Should indeed download the depended jar(s). You may need to approve "Import Changes" dialog if it pops in, or enable auto import.
2 - Seeing transitive dependencies
It can be achieved via Maven Dependencies Diagram - unfortunately only in IntelliJ Ultimate edition. You can use Maven Dependencies Plugin to see the dependencies tree in your favorite CLI.
Question 1: Adding a dependency
In Eclipse, depending on how you created the project, you should be able to add dependencies that are automatically recognized using the maven context menu.
Note that you should have created the project using the eclipse maven plugin so that it has maven nature.
To add dependencies/plugins from a remote repository, you can search in the resulting UI for a dependency if you know the artifactId or groupId. The plugin will pull up the deps whether the repo url is specified in the pom.xml or not.
After adding a dependency to the POM, the IDE will start downloading it and all transient dependencies as soon as you save the file.
If something goes wrong, you can try to "Update Project" from the context menu.
Question 2: Determining transitive dependencies
Transient dependencies are visible in the "Dependency Hierarchy" tab of the POM editor.
I usually default to the command line because it allows much more flexibility and functionality when tracking the dependency graph.
I am sorry but I have not worked with IntelliJ
I made a Hello word example in springMVC.Following are my steps.
1.Installed maven-eclipse integeration in eclipse.
2.Download maven and set environment variables,JAVA_HOME etc.
3.Check to see if maven is running via cmd and it is.
4.Create new maven project and in pom.xml,set spring core,web,web-mvc dependencies.
5.Create new Dynamic web project and under its properties->Deployment assembly I have added maven project.
6.Added spring jars core,mvc,web,context etc in dynamic web project lib folder.
It's all working now but I am not able to understand the working.
Before,I was trying to make it work without maven by copy and paste jars into lib,classpath,by makiing user library and adding jars to it and then add it to current project but every time it was giving some error.Sometimes it was classnotfound,sometimes it was context related.
Finally i tried this maven thing by searching some online tutorials and it works now.
But I am not able get it.Can anybody explain me in detail that how those spring jars getting picked during development and deployment.What exactly is maven doing that I was not doing before.I am in the state of total confusion.I know the flow of my mvc project(controllers,views etc.).
Maven searches the libraries (they are also called artifacts in the Maven language) in repositories. In the Maven Central Repository many libraries are hosted - http://search.maven.org/. After Maven finds the libraries in a repository, it caches them in your local repository. It is in ${userDir}/.m2 The next time, Maven will look in your local repository, instead of downloading again from the Central Repository.
P.S You can specify many other repositories different than the Central Repository. This is done in the <repositories> tag in your pom.xml. The Central Repository is always searched by default.
if you don't want use maven you have change your project setup. remove the pom.xml and copy all needed jar into the webapp/WEB-INF/libs folder.
Copy the jar from the a maven build(target folder). in this case you have all together without grabbing them one by one over then.
I have moved to Maven recently, and since it works fine for resources up to date in some repositories, it's not obvious for non-maven ones.
I have something very simple to achieve (in the idea), but that I am unable to express so far:
I need to compile my code with a jar that can be found here:
https://hudson.eclipse.org/hudson/view/WTP/job/cbi-wtp-wst.xsl.psychopath/ws/sourceediting/plugins/org.eclipse.wst.xml.xpath2.processor/target/
What do I have to put in my pom.xml to make Maven downloading the .jar + the java source + the javadoc, and eventually the other dependencies (actually IBM ICU, Xerces, JavaCup) that are mentionned in the supplied MANIFEST ?
I have read lots of documents, including those with a plugin called Tycho, but nothing helpfull for that simple task.
Thanks for your help.
Maven only works well if all artifacts needed for a build are contained in the local or a configured remote repository. So you have to do the following jobs:
Find out if eclipse plugins are deployed in a Maven2-style repository, and what the URL of that repository is.
Then find out which version of that plugin (artifact) you need.
Maven allows you to configure what will be copied locally: jar file, sources and api doc if you want to.
Maven should then be responsible to download as well all needed artifacts for the plugin you want to use.
After looking at the contents of the URL you gave us (especially the file p2content.xml), it looks like there should be a repository. I searched for the maven repository for org.eclipse.wst.xml.xpath2 and found the URL http://maven.eclipse.org/nexus/content/repositories/testing/org/eclipse/wst/org.eclipse.wst.xml.xpath2/1.1.0/org.eclipse.wst.xml.xpath2-1.1.0.pom
So the repository you are searching for is located at http://maven.eclipse.org/nexus. Just open it, search for example for xpath2, and Nexus, the repository software used there will you show the available artifacts. Depending on what was deployed to that repository, it may contain only the library, or have even sources and JavaDoc bundled with it. For the example above (xpath2), there seems to be only the POM itself and the library (the jar). If you take as example junit, you will find all versions and variants, even with sources.jar and javadoc.jar.
After you have found the needed artifact, you can include it in the dependency section of your POM. And you have to add http://maven.eclipse.org/nexus as a remote repository in the configuration of your Maven installation.
The question and its answer Get source JARs from Maven repository explain how to fetch sources and JavaDoc (if they are available).
You need a maven repository which contains this artifacts (i don't know, if Eclipse hosts a repository for their projects). You can also deploy manually the artifacts to a local repository on your computer.
I have a list of Eclipse projects that I would like to compile based on the existing project configuration.
As far as I can tell, if an ant script could read the .classpath files, it would pretty much be able to infer the project dependencies and perform a "javac" compilation in the right order. This would save time in describing the same dependencies again in the ant script or a Makefile.
The dependencies I am interested in are JAR Dependencies, JRE dependencies, and inter-project dependencies. These are -- as far as I can tell -- part of the .classpath XML file.
Any ideas on how Eclipse project dependencies could used in an ant script?
Right click on your Project -> Export
"General/Ant Buildfiles".
Choose the projects and there you go.
Otherwise...
I have some experience with ant4eclipse and it is a hassle to get it stable.
Go check Buckminster or Maven Tycho for a good solution.
I'm currently using Ivy along with Ant, Eclipse and Maven.
I just love the way Ivy works.
Currently, we have a workspace with many projects using Liferay (with Tomcat) for the front-end and Glassfish for the back-end.
We were looking for a way to manage our dependencies a lot better than how we were doing it.
So I took Ivy, replaced all of the classpaths and deployment dependencies in eclipse and was able to build my application using 1 ivy file per project using either Eclipse or Ant.
Ivy integrates like a charm in ant and builds are done either from the workspace or by command line.
I strongly suggest you look at this avenue. Additionnaly, by adding Artifactory, we have a local repository in which the ivy files look for dependencies. This helps us maintain and rule which jars are to be used by developpers. Once everything is setup, we will build our application nightly using Jenkins and these builds will be using our Artifactory repository to resolve dependencies since our build servers do not have access to the internet.
Hope this helped
If you are running the Ant script only from eclipse using the "External Tools Configurations", you can add the variable ${project_classpath} to the Classpath.
Depending on if you are in a plugin project and dependencies you might need to add the
${eclipse_home}.
In case you get an error launching Variable references empty selection: ${project_classpath}, make sure the ant xml file or at least the project is selected. This is important.
I believe the ant4eclipse project provides support for executing Ant builds based on Eclipse metadata files.
However, in my opinion that is doing things back to front. You shouldn't have your build (Ant) depending on your IDE (Eclipse) environment. But it is useful if you can derive your Eclipse environment from your Ant build.
This is an approach used successfully in a team I worked in. We had a helper Ant target which applied XLST to project build.xml files to transform these into Eclipse .classpath files. Thus the Ant build.xml files were the single configuration point for our projects.