I'm using m2e (1.0.100), Eclipse (Indigo SR1) and hibernate-jpamodelgen (1.1.1.Final).
I want to have hibernate generate the Canonical metamodel from my entities when I compile the projects.
I was able to do this previously when I was working on a non-maven project and I followed the numerous tutorials there are on how to configure the eclipse project to use this jar.
However, to the best of my understanding, when using m2e it is best (mandatory?) to let it do the eclipse configuration for you and so I'm not sure how this should be done.
This hibernate tutorial explains how to use the generator with maven and eclipse but separately.
I think what I'm missing is gluing my pom, which was generated as a simple no archetype pom, and my eclipse project configuration so that they enable me to do some JPA magic.
BTW, following the above tutorial for maven caused my maven-generated jars to contain the _ classes but these are not seen by eclipse since they are only in the jars and not in the actual projects.
Thanks in advance
I've asked the same question on the m2e-users mailing list and got the following answer (link for those wanting the full thread):
Basically one should manually configure (for example using the above mentioned hibernate tutorial) eclipse to use the generator and configure the same directory maven uses (for me it was target/generated-sources/annotations) as the output directory.
According to the committers of m2e, the project currently does not change these eclipse files and so this won't be overriden from them.
The problem I did face was that this information is lost (and so the manual change is needed again) when using GIT and switching between branches as I don't want to commit any eclipse related files to the SCM.
Currently this is an acceptable solution and I hope m2e will be able to add this missing feature.
Update
The information that is lost, at least according to my experience, is the definition of the target/generated-sources/annotations folder as a source folder. Just as an FYI.
Related
I am trying to generate jaxb2 classes on an Intellij Build.
I mean this button :
You can use this project as a template : https://github.com/spring-guides/gs-consuming-web-service/tree/master/complete. If you checkout the project and try to build it, you'll see it does not compile. You have to run a mvn:compile, which is, to me, not really obvious if you a working in a team and you don't know there are supposed to be generated classes.
It would be better if it could work with this build.
I've seen it is possible with mapstruct so I guess it could with jaxb2 as well. Do you know how to do that? Maybe some configuration in the pom...
Thanks.
If you include the generated sources folder in your project definition then this will be picked up by the IntelliJ build process as detailed here...
Unable to use Intellij with a generated sources folder
Depending on your exact requirements, however, you may also want to get IntelliJ to generate the sources which is detailed here
IntelliJ Jaxb code generation
I am new to using github and have been trying to figure out this question by looking at other people's repositories, but I cannot figure it out. When people fork/clone repositories in github to their local computers to develop on the project, is it expected that the cloned project is complete (ie. it has all of the files that it needs to run properly). For example, if I were to use a third-party library in the form of a .jar file, should I include that .jar file in the repository so that my code is ready to run when someone clones it, or is it better to just make a note that you are using such-and-such third-party libraries and the user will need to download those libraries elsewhere before they begin work. I am just trying to figure at the best practices for my code commits.
Thanks!
Basically it is as Chris said.
You should use a build system that has a package manager. This way you specify which dependencies you need and it downloads them automatically. Personally I have worked with maven and ant. So, here is my experience:
Apache Maven:
First word about maven, it is not a package manager. It is a build system. It just includes a package manager, because for java folks downloading the dependencies is part of the build process.
Maven comes with a nice set of defaults. This means you just use the archtype plugin to create a project ("mvn archetype:create" on the cli). Think of an archetype as a template for your project. You can choose what ever archetype suits your needs best. In case you use some framework, there is probably an archetype for it. Otherwise the simple-project archetype will be your choice. Afterwards your code goes to src/main/java, your test cases go to src/test/java and "mvn install" will build everything. Dependencies can be added to the pom in maven's dependency format. http://search.maven.org/ is the place to look for dependencies. If you find it there, you can simply copy the xml snippet to your pom.xml (which has been created by maven's archetype system for you).
In my experience, maven is the fastest way to get a project with dependencies and test execution set up. Also I never experienced that a maven build which worked on my machine failed somewhere else (except for computers which had year-old java versions). The charm is that maven's default lifecycle (or build cycle) covers all your needs. Also there are a lot of plugins for almost everything. However, you have a big problem if you want to do something that is not covered by maven's lifecycle. However, I only ever encountered that in mixed-language projects. As soon as you need anything but java, you're screwed.
Apache Ivy:
I've only ever used it together with Apache Ant. However, Ivy is a package manager, ant provides a build system. Ivy is integrated into ant as a plugin. While maven usually works out of the box, Ant requires you to write your build file manually. This allows for greater flexibility than maven, but comes with the prize of yet another file to write and maintain. Basically Ant files are as complicated as any source code, which means you should comment and document them. Otherwise you will not be able to maintain your build process later on.
Ivy itself is as easy as maven's dependency system. You have an xml file which defines your dependencies. As for maven, you can find the appropriate xml snippets on maven central http://search.maven.org/.
As a summary, I recommend Maven in case you have a simple Java Project. Ant is for cases where you need to do something special in your build.
I am sorry i don't know maven good enough for the complex environment i am currently working in (1k+ applications, most of them are Java EE). I still give it a try to describe what i want to archive:
0.) There is a company framework that abstracts the Java EE World a bit and is used in all the Java EE components
1.) I checked out the maven project of the Java EE component i am working with
during the build it downloads the dependencys of other components out of the companys repository and stores it inside my local repo for compilation. So i can see the jar-files of the companys framework inside my local repo.
2.) I now want to change some of the frameworks functionality for a local test so i checked out their sources from another SVN repository. I made the changes and build that framework component with maven "clean install".
3.) I rebuild the component i am working with as well.
Inside eclipse i can now click on one of a frameworks classes method and it opens the according source. But this only happens because the local repo is meant to contain source-jars for any dependency as well. So in my editor i can see this source is from the jar of the framework in my local repo and i cant change anything.
Could someone please give me a hint how i can archive the following:
I can make changes to the framework (and build the frameworks jars with "clean install")
I can build my component and it uses the above compiled framework jars rather than the "old" ones from the local repo.
I will right now start to read the entire maven documentation and each and every section (i try to understand that dependency management since 1 year and still don't get it) but i would really appreciate if you could help me out a bit here.
I don't know how Eclipse manages maven dependencies, but
In IntelliJ IDEA this is simple - if maven dependency is in project then IDEA uses it instead of dependency from local repo.
So if u want to edit framework source code and use this changes immidiately - i think that framework should be in your Eclipse Workspace. And your module in Eclipse should reference framework artifacts directly - not over Maven dependency mechanism.
I think that this is a Eclipse Maven plugin responsibility. Do u have any installed Maven plugin for Eclipse? (M2Eclipse for example)
I'm new to Maven, using the m2e plugin for Eclipse. I'm still wrapping my head around Maven, but it seems like whenever I need to import a new library, like java.util.List, now I have to manually go through the hassle of finding the right repository for the jar and adding it to the dependencies in the POM. This seems like a major hassle, especially since some jars can't be found in public repositories, so they have to be uploaded into the local repository.
Am I missing something about Maven in Eclipse? Is there a way to automatically update the POM when Eclipse automatically imports a new library?
I'm trying to understand how using Maven saves time/effort...
You picked a bad example. Portions of the actual Java Library that come with the Java Standard Runtime are there regardless of Maven configuration.
With that in mind, if you wanted to add something external, say Log4j, then you would need to add a project dependency on Log4j. Maven would then take the dependency information and create a "signature" to search for, first in the local cache, and then in the external repositories.
Such a signature might look like
groupId:artifactId:version
or perhaps
groupId:artifactId:version:classifier
This identifies a maven "module" which will then be downloaded and configured into your system. Once in place it adds all of the classes within the module to your configured project.
Maven principally saves time in downloading and organizing JAR files in your build. By defining a "standard" project layout and a "standard" build order, Maven eliminates a lot of the guesswork in the "why isn't my project building" sweepstakes. Also, you can use neat commands like "mvn dependency:tree" to print out a list of all the JARs your project depends on, recursively.
Warning note: If you are using the M2E plugin and Eclipse, you may also run into problems with the plugin itself. The 1.0 version (hosted at eclipse.org) was much less friendly than the previous 0.12 version (hosted at Sonatype). You can get around this to some extent by downloading and installing the "standalone" version of Maven from apache (maven.apache.org) and running Maven from the command line. This is actually much more stable than trying to run Maven inside Eclipse (in my personal experience) and may save you some pain as you try to learn about Maven.
I'm having some issues making the maven google app engine plugin work properly.
First of all, I'm not even sure if the archetype I'm using is the correct one, their examples show version 0.7.0 but it seems like never versions exist (i tried 0.9.1 and that works), where can I find a overview of what versions of the plugin is available?
Secondly, the archetype seems.. messy, I don't like the package structure and it doesn't seem to actually include the GAE and GWT dependencies. I have to manually add them to my project in Eclipse, which kind of defeats the purpose of using maven. And how come they are breaking the gwt maven plugin? I know that one includes the actual gwt jars as maven dependencies?
I'm fairly new to Maven, but I have been using the gwt maven plugin for a while, and I'm very happy with everything about it. Is there any way I could just their archetype to do the base project and add the gae plugin to it?
UPDATE
I suspect the problem I'm seeing with the GAE maven plug-in is in regards to undefined properties in the POM. I have no idea if its due to error these aren't set-up or if its due to me actually have to manually set them up. The documentation on this plugin is sparse.
Thanks for the answer below, but I really don't want to add another archetype into play. I think the best solution for me is to try and adapt a GWT maven project manually, to include support for GAE.
I've used the archetype like so :
http://code.google.com/p/gae-mvn-archetype/
to generate a GAE project template.Then manually added my other dependencies. This got me a usable project which I can deploy to GAE and everything.
Also, for Eclipse importing, once the template project was done, I've imported it into eclipse using the m2_eclipse plugin :
http://m2eclipse.sonatype.org/installing-m2eclipse.html
(note that i've imported it into Eclipse as a Maven project, NOT as an Eclipse whatever project)
This imported the thing into eclipse with all the necessary dependencies and without errors.