My company starts a new project next week. We have planned to develop the application with eclipse rcp. The build process should be fully automated, so we're prepared to set up a continuous integration environment (e.g. Continuum). For the build-automation-part I intended to use maven2, because I want use its dependency management.
I have used maven2 for a small old-style java project, but have never set up maven for using it with eclipse rcp.
What's the best way to do this? Basic concepts? Common traps? Are any tutorials or book's around there? The tutorials and informations I found, seemed outdated or incomplete.
PS: The main project will be divided into sub-project's (plug-in's). But I think this is typical for eclipse rcp projects.
You should take a look at Tycho:
the-future-of-maven-osgi-join-the-tycho-users-mailing-list
the-next-generation-of-build-tools-for-eclipse-plugins-and-rcp-applications
Like most Maven questions, this is solved by a link to a plug-in:
"pde-maven-plugin"
Other advice:
use the assembly plug-in to build
the update site
consider using hudson rather than
Continuum
I've been battling maven2/Eclipse RCP integration for some time. The key is not so much getting your setup right: You can get it to work - eventually - by reverse-engineering Eclipse's build process in maven.
In my experience, the hard part is keeping everything up to date. Every time Eclipse revs their libs, you'll find yourself re-writing a bunch of pom files for that newest RCP widget or SWT lib. Naturally, CI helps with this somewhat. The problem is that Eclipse and maven are very particular about the way they do the business of building, and their approaches are quite different. To make matters worse, PDE dev (and Eclipse dev, more generally) is powered by a lot of wizard code, which is sometimes quite opaque as to what's happening behind the scenes.
The question you really need to ask yourself is if it's worth the effort. In my particular case, I believe it has been. (CI is too good to live without.) But the trade-off is that you may find yourself being the "build guy", which can take valuable time away from actual development, which is probably what you enjoy most.
I've got recently the same problem : build eclipse RCP application through continuous integration.
I haven't applied them yet but I've found some interesting articles :
Here's the documentation for Tycho
Building Eclipse Plugins with Maven 2 on eclipse.org
Build Eclipse RCP products using Maven 2 - how hard can it be? from Immo Hüneke's blog
Here's an article about PDE build automation
Here's a shell script to automate JUnit test launch
Related
another completely beginner question. I just went through two introductory courses in Java, and I noticed that Eclipse can also support development in other languages (which I didn't know). Does anyone know how to add other languages to Eclipse so that I can switch between IDE's, or do I have to have a completely separate installation of Eclipse per language?
In Eclipse, use the menu Help -> Install new software. Choose "All available sites" in the combo box, wait a moment and then you can explore some other available plugins and languages.
Depending on your version of Eclipse, you might also have a menu item Help -> Eclipse Marketplace. That one is even more comfortable, as it allows you to easily browse all plugins listed in the Eclipse Marketplace. You can also browse the marketplace in your browser and afterwards drag and drop interesting plugins from the browser to your running eclipse (if your version of eclipse is new enough).
Eclipse is a plugin framework......
You have two choices - fortunately the eclipse community saw fit to produce Eclipse in a range of products that will do 99% of what 99% of people want. These distros are good to go. You install them and start work. You can then extend them if you want, but they do all of the basics very well, reliably, out of the box. Installing more than one with eclipse is easy, they do not interfere with each other, and if one turns out to be broken, the rest are not affected.
The other option, is to extend the framework by adding the plugins you want. So you start with an Eclipse distro, and download and install plugins till the cows come home. In the perfect world, this would be the perfect solution. Its not a perfect world..... you have not installed all you plugins and Eclipse suddenly crashes........
Problems occur because sometimes
Plugins are buggy
Plugins are incompatible with each other.
Different plugins rely on different versions of another one
(indirectly incompatible).
Plugins don't work the way the rest of the tool does
There are just too many plugins to choose from - you don't need most, and the ones you need can be hard to find.
Adding more than a few (probably 1) plugin to Eclipse exposes you to these problems. This is not something for the novice or people who have job not involved in fixing Eclipse. if you have a real reason for it, like your a sadist, or it's your job, or you want it to be your job, to make a team of 100 Devs productive, then plugins are great, otherwise, download a pre-canned, tested, reliable distro and take advantage of the great work by the contributors.
I requested Maven training at work, and the bosses want to hire someone who knows Maven to come work with us as a consultant so that we'll learn Maven from a real-world perspective instead of a training perspective.
I've been tasked with coming up with questions of various difficulty to ask potential hires in order to ascertain their Maven ability. The problem is that I don't fully understand Maven yet (hence the training request).
What questions would you ask someone to determine their Maven ability, and what level of knowledge would someone have to have of Maven to answer them?
In my opinion, a "Maven consultant" should:
Have a good understanding of how Maven differs from other build tools like Ant (Maven provides a "lingua franca" for project management).
Have a good understanding of Maven principles: Conventions over Configuration, the default layout, the naming conventions, the philosophy of the tool (one primary output per project).
Have a good understanding of how Maven works: from where the conventions are coming from (the super POM), the lifecycles (main, clean, site), the phases, how plugins are bound to phases, the influence of packaging, etc
Know what profiles are and how they can be used to deal with different environments, how to trigger them.
Know how to use plugins, how to configure them, how to plug them in a maven build.
Know how repositories work, the difference between local and remote repositories, what SNAPSHOT dependencies are.
Know how dependencies are resolved, what transitive dependencies are, how to control them, what dependencies scope are, how to use dependencyManagement.
Know how to implement code health checks, the essential plugins (Checkstyle, PMD and Findbugs plugins), how to implement various kind of tests (unit, integration, functional), how to measure coverage, when to fail the build, when to report.
Know how to setup maven in a corporate environment (using a shared repository, setting up CI, a company POM).
Know how to handle advanced packaging scenarii (with the assembly plugin)
Know how to handle deployment, the various protocols, the deploy plugin, the release plugin, the SNAPSHOT resolution.
Know how to setup a Maven build for a Java EE project, how to setup a multi-modules build, what modules are required, how to test in the development environment, how to handle the production environment.
Someone with these skills should put you on the right path (and has very likely a decent experience of Maven).
A lot of good questions here, especially the ones proposed by Pascal Thivent. However, I would ask another question:
Q: What is the difference between the aggregation and inheritence in Maven?
A: You can have a short explanation here.
I would suggest that you think about what you wanna do with Maven, or why you wanna introduce it into your projects. Maybe ask your boss for his reasons/goals in introducing Maven.
After you have named your main goals why to introduce Maven. Ask potential consultants how they would use Maven to achieve those goals.
Examples 1
Goal: Improve overall code quality in project.
Question: How may we use Maven to improve our overall code quality in projects.
Possible answer: Maven has several plug-ins to force/meassure code quality in projects, we could integrate those into our buildscripts in almost no time. (e.g. checkstlye, pmd, cobertura, xradar...)
Examples 2
Goal: Creating automated deployment scripts for several destination environments.
Question: How may we use Maven to automatically deploy artifacts to several destination environments.
Possible answer: We could use Maven plug-ins for deployment (e.g. Cargo) and use maven's profiles to handle several configurations.
a.s.o.
I would ask:
Describe what is the practice of SCM?
Describe your ideal Maven infrastructure (server, repositories, CI, plug-ins, conventions, etc.)?
Both are very open questions, but they should give your a feeling of his skills and what you can learn from him and what he could bring to your company.
EDIT
Maven is just one piece in the overall software configuration management (SCM) strategy. A good consultant should know the details of maven in and out but also know how it fit in the big picture. Just like you expect a Java EE consultant to be expert in a Java but to know what it means to deliver enterprise application to a customer.
In the company I worked, we had a guy responsible of the SCM who had been a Maven contributor. And his view was way broader than "just" maven. He was in charge to have a productive build, configuration and release process. Two examples:
We were hard-coding the release number in java code to be able to display it into the "about" dialog of our desktop applications. Most of the time we forgot to change it after the release resulting in a mismatch between the actual release number and the about dialog -- big problem for integrators on-site. This was a bad practice. He then set up something so that the release number in Maven would be correct in the manifest file and educated us to read the manifest file from Java to ensure both match.
When you would release a module, he wrote a script to not only build the application, but also close the corresponding version in the ticket system (JIRA) and push the release notes in the wiki.
All that to say that knowing how to "mavenize" a project is important, but more important, the guy must understand how you currently work, what is in place and help you set up something reasonable to improve your productivity.
Here are the questions I would ask:
How would you enforce the use of JDK6
for a group of projects?
How would you enforce the use of a
particular version of a plugins?
What are some of the reasons why you
would use an assembly to build a jar
rather than the jar plugin?
Describe the process of releasing a
Java EE project made up of an EJB, a WAR
file and two utility jars.
How many repositories should an
internal company repository server have and why?
How would you structure a POM project made up of N child projects so they it can easily be used in Eclipse?
All of these questions have at least two answers. I would be looking for someone who can provide at least two answers and point out the pros and cons of each approach. Ideally, this person should be tweaking the set up to be less disruptive to the way your environment already works.
If you have the luxury, I suggest having the consultant come onsite for a day, give him/her an existing java project that you're working on and have him/her "mavenize" it for you. The next day, sit with him/her and have them explain how to compile, and build a jar (or war).
Or maybe have them come to the interview with a maven project to demonstrate. The should be able to compile, and build a jar/war at the very least, imo. If they can run unit tests, deploy to tomcat, integrate with any of the various frameworks like gwt, hibernate, spring, etc, then even better.
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I am really tired of struggling with Maven 2 all the time. Build tools should not be in the way. Recently I have been looking at Buildr and Gradle. Maven 3 seems to fix some of the struggles. So, what should I go for now? Buildr? Gradle? Or wait a year for Maven 3?
I wouldn't expect too much from Maven 3. The people behind the Maven pedigree of build tools have always held the assumption that project builds are homogeneous, that is: all build problems fundamentally boil down to the same problem. This view of the world can be held fairly consistently in the face of opposing views but comes at a cost. The absence of scripting logic in Maven ("when you want to script you know you're doing something wrong"), the cumbersome plugin API ("no ordinary Maven user should want to write a plugin") and the central repository ("we all have the same dependencies") are all testaments of this overarching assumption.
In the real world build problems are heterogeneous because people build software for a wide variety of reasons. They all 'develop' like we all 'drill holes' once in a while for solving unique problems. Regardless of your level of abstraction you'll always find similarities when comparing arbitrary build problems. It is the reveration of these similarities and the condemnation of differences that is the downfall for Maven's design and the reason why it draws so much flak. Basically, Maven is authoritarian and utopian in its outlook.
PS: Maven has good features, like convention-over-configuration and the idea of using repositories (the Maven implementation of this idea is troublesome).
No build system is a magic bullet. I find Maven solves more problems than it causes for me, but I'm quite comfortable writing plugins to get round its shortcomings, I also deal with hundreds of projects, so Maven's inheritance and dependency processing is quite helpful for me.
Browse SO a bit and you'll see Buildr and Gradle both have issues too (same for Ant and Ivy), generally you're trading one set of problems for another and its a case of finding the least painful.
Is there anything in particular that is bothering you about Maven or is it a general itch? If it is a particular problem it is worth looking at the Maven 3 issues on Jira, if the problem isn't addressed, you can raise it, or else there may be little point in you waiting
We use Maven here, but I find that once you get outside of a simple project, the pom.xml starts to get more and more complex. You start spending a lot of time working out how in the heck to configure your pom to do what you want, and how to work around the various issues.
The thing that really got me was the ear we're building. We have multiple wars in that ear file, and Maven normally sticks the libraries in the wars. However, to reduce the size of the wars, and to keep the jars all the same, we wanted to put the jars shared between the wars in the ear's lib directory.
Unfortunately, Maven doesn't handle this very well. We needed to manually configure this for each of the wars' poms, and then add all of these dependencies into the ear's pom.
In another project we have HTML based help files. The people who write the help write them in Microsoft Word then use a program to translate them into HTML. A single character change can reverberate throughout hundreds of files.
To get around this issue, our help system is stored in our source repository as a single zipped file. When our documentation team creates a new set of help files, they zip it up and replace what is in the repository.
So, part of my build is unzipping this file and placing it in the war. Easy to do in Ant, can't do it in Maven unless you use the Antrun plugin which allows you to write Ant code to handle issues that Maven cannot handle without a full blown plugin.
I can see what Maven is doing, but theory got ahead of reality. What I found is that Ivy and Ant can do most of the dependency checking that Maven does without all the issues of writing and maintaining the poms.
If you're not already using Maven, try Ant with Ivy first. Then when, Maven 3 comes out, try that. I remember the transition from Maven 1 to Maven 2. They were entirely incompatible with each other and anything you learned using Maven 1 was obsolete. It would be silly to learn and redo your projects in Maven 2 to suddenly find yourself redoing everything for Maven 3.
maven 3.x is already embedded in IDEs (at least on netbeans, check this link for more infomration). You can play today with maven 3.x simply building a Maven project with netbeans.
Another nice news is that maven got more 'enterprise' support with integrating EJB/WS in IDE projects (again, at least on netbeans).
So I would stick to maven 2.x for production builds and play with maven 3.x for development.
Maven 2 and 3 have both been working perfectly for me on a variety of projects. I am currently using Maven 3 alpha 7 which works very well, especially in conjunction with the Eclipse Maven plugin.
Maven integrates seamlessly with Ant - in both directions. In my current project, we invoke Maven from Ant multiple times in order to perform complex integration test. Likewise, we use Ant via Maven's AntRun plugin, and we also wrote our own Maven plugins. This, by the way, is a matter of minutes and boils down to writing an annotated Pojo.
Maven gets a lot of flak because many developers don't like rules or conventions. Quite simply, nobody forces you to use Maven. If you want ultimate freedom - by any means - re-write your own build process for every project you join. However, if you like to create software rather than re-inventing the wheel with a custom-made build process on every project, go for Maven.
Keep your code well maintained and broken into well defined modules and porting between build systems becomes a minor problem.
As for now, maven-2 is a good choice for the middle 2/3rd of projects. For the really simple, ant is still ok. For the really complex, a hybrid of maven-2 and other tools (like antrun) becomes inevitable.
Not sure why you are having problems with maven-2.
It differs from ant and buildr in that it is a tool for describing your build process, not scripting it. Complex builds, the ones with multiple dynamic parts and nested and/or transient dependencies are hard to build because they are hard to describe.
Give Lattice https://github.com/hackingspirit/Lattice a try. I am the author. Here is the scoop:
In Lattice build files are written not in XML, but in the Python language. The ben- efits are much better readability and powerful imperative build scripting supported by Python.
For multi-module projects. Lattice uses topological sorting to decide the correct order to build each module. It’s also planned that Lattice will analyze the module dependency to determine how the module compilation can be parallelized.
Lattice’s source code is extremely lean, currently it consists of about 500 lines of Python source code.
I think people complaining about Maven should spend a little extra time investigating available plugins. In response to comments complaining that Maven is rigid and makes it hard to use custom build logic / provide fine-grained control over the build process - I would recommend looking into Ant plug-in for Maven (there are actually several, but here is one: http://maven.apache.org/plugins/maven-antrun-plugin). I have had great success customizing Maven builds with it over the years. Basically, it allows you to run any Ant command as part of the Maven build, and you can do pretty much anything with Ant ;)
Ant with Ivy does the same dependency management Maven does (in fact, it uses Maven's whole dependency management infrastructure including the same URL repositories), but without all the POM configuration mess.
Ant with Ivy might be a way of handling the dependency issues for people who really don't want to use Maven. It solves 90% of the stuff that Maven was suppose to solve.
I am experimenting with Groovy Griffon development and I am wondering what IDE to use.
I am trying to use NetBeans 6.5, and I found this post
https://blogs.oracle.com/geertjan/entry/notes_on_converting_netbeans_grails
essentially it describes forking the NetBeans trunk and hacking the Grails support; I was hoping for something more lightweight.
Are there any simple tools to create eclipse, netbeans or pom.xml's from Griffin Apps?
Or is it best to use a simple text editor?
There is a NetBeans Griffon plugin already available at http://plugins.netbeans.org/PluginPortal/faces/PluginDetailPage.jsp?pluginid=18664
Griffon apps have some rudimentry hooks already for IDE integration.
First, a .classpath and .project file are generated that mark the expected source and test directories for Eclipse. Both IntelliJ and NetBeans have importers for these eclipse files (and they work, I use them regularly).
Second, Griffon 0.1.1 adds more targets to the parallel build.xml so that more of the common scripts can be used as though they were ant tasks (run-app, compile, debug-app, etc.)
Third, there is some better IDE support in the works form some of the IDE vendors. As mentioned in the article you linked because Griffon is grails derived it is fairly easy to re-purpose existing Grails support. IntelliJ has the only specific tracked feature request I am aware of.
IntelliJ Idea has very good Griffon support.
This question usually comes with a next question:
How to debug Griffon?
Just in case someone still requires a helping hand trying to figure out how to debug Griffon in Eclipse/STS I've written a simple step by step guide to get it done:
http://ivo43.blogspot.com/2012/02/debugging-griffon-in-eclipsests.html
Hope it helps someone someday, :D
PD: I've tried Netbeans and even though it looks great am still with STS, call me a maniac!
I was wondering about the best way to manage projects dependencies from ant. What are the pros and cons of the Maven Ant task and of Ivy?
Since what you're wanting to do is add dependency management to an existing Ant project, that's precisely what Ivy's designed to do. Dependency management is a big part of Maven, but far from all of it. Maven is more of a project-oriented tool that does several other things in addition to dependencies. It would be worth considering if you were planning to migrate to Maven and use additional Maven features as well, but it's a bit much if all you'd use it for is to spin off Ant.
Your type of dependencies and your expectations for how they behave will also make a difference. Pulling third-party dependencies is almost trivial in Maven, while Ivy excels in rebuilding your own dependent components. In either case, the tools won't provide decent build, versioning, and repository policies, those are still up to you and needed to get the configuration right.
Ant + Ivy == A campground, where people use the facilities as needed.
Maven == A resort, where you rely on someone else to provide services.
Maven is easier for a team lacking build/integration experience, but when the team needs to diverge from Maven standards they will find themselves reaching for groovy, gradle, and the lack of solid documentation will become frustrating.
Ant + Ivy will take longer to startup a project, but if the team has build/integration experience they can tailor the build system around they way they develop and release code.
In engineering... technology companies I always push for the campsite solution versus the resort.
It is amazing though that both Ant and Maven choose XML as their langauge to express build recipes with. The Java community is stuck on that XML...
I think this blog post covers exactly what the OP is looking for:
Why you should use the Maven Ant Tasks instead of Maven or Ivy
Ivy+Ant is far, far more flexible. Ivy does dependency management, period, and it does that extremely well, better than Maven. And with Ant you can pretty much put together any build system that you want.
Maven tries to control everything - the "lifecycle" (compile, test, package, etc.), where files should live, and so on. Have fun customizing plugins and the like if you don't like the "Maven way".
Maven is the answer to a question no one asked. Writing an Ant script is not hard, and Ivy gives you better dependency management than Maven. I am confused by some of the previous comments stating they couldn't get Ivy working. Ivy is quite a bit simpler than Maven to get up and running.
The Spring Framework uses Ivy in its build process. I think that can be seen as quite a vote of confidence for Ivy.
If your long term goal is to migrate to using Maven to manage the entire build process (which one might intend to do for new greenfield projects), then I heartily recommend using Maven pom.xml files to manage dependencies on behalf of Ant build.xml files. The end result is that both your greenfield projects and your legacy projects are then all using the same mechanism to manage dependencies. And it turns out Maven really does a better job of managing dependencies for Ant build.xml files than does Ivy.
Prior to adopting Maven as our flagship build tool, I had a developer attempt to use Ivy in combination to existing Ant build.xml files. This was most frustrating experience that very soon lead us to reject Ivy. We went ahead with an adoption of Maven. Our greenfield projects began to be built with the stock Maven approach, etc.
However, I went back to the Ant legacy projects and started using the Maven Ant task to define classpath definitions (and occasionally other Ant property definitions pulled in from the pom.xml). This turned out to be a most superlative experience. The existing Ant build.xml files need only be modified slightly to use Maven ant integration to define any classpath that were in use in the build.xml file. All dependencies required by the project became defined in an accompanying pom.xml file that gets processed by Maven via the Ant task incorporated into the build.xml files.
Maven scopes can be used to fine tune classpath definitions such that one suitable for compiling, or running unit test, or for packaging, et al, can be established. Also, pretty much any element of something defined in the pom.xml file can be referenced as an Ant property within the build.xml file.
Really with the Ant task for Maven there is no viable reason for Ivy to even exist.
Comparing Maven with ivy/ant is to compare a smartphone to telegraphy.
If you want to leverage a real enduring effect in your build infrastructure, it's better to use Maven because it anticipates and abstracts all processes and tasks every software project or other software-like project is faced with. I took part in many projects and if your projects get more complex and more diverse and more heterogeneous, you will praise even more the simplicity of a Maven project configuration. Indeed, it will become complex but not complicated compared to ivy/ant-driven projects.
The main advantage of Maven is "convention over configuration" (http://en.wikipedia.org/wiki/Convention_over_configuration) a very important paradigm. In short, this means that you don't need to know/configure things that are obvious/trivial/commonplace. Although Maven and all its plugins ship with many default-settings, you always have the option to configure your projects for your special needs. With Maven, on the one hand you can setup a project very easy and quickly; on the other hand, you can customize a growing project up to your needs with minimum effort. If you have understood the key concepts behind Maven you will leverage every project and also projects that are not typical software development projects as well.
In the past, I wrote many ant scripts and with upcoming Maven I began to hate ant. One disadvantage is that you always copy scripts and repeat yourself, develop ant tasks that don't repeat tasks that don't repeat tasks that don't repeat... And the main disadvantage is that growing ant scripts tend to get unmaintainable, especially if a dozen ant geeks want to pimp up each others ant scripts.
Many ant-enthusiasts suffer from getting overall control over trivial things like copying of artifacts and printing buildmessages. But because Maven's key concept is to hide these trivial things the legend will forever keep alive that Maven restricts customization needs. But don't worry, that’s a legend! And so you finally understand my initial statement: don't bother with trivial things that are already solved.
Maybe ivy/ant is an option for simple projects but for complex growing projects you need simplicity and conventions. Otherwise you will be overwhelmed with more and more maintaining problems. Especially if you have many dependent projects, technologies and heterogeneous product parts in a global project you don't have time and money for developing and testing ant scripts or solving dependency problems.
Another advice should be mentioned: Ant offers the integration of Maven. This integration is often used to test and play with maven in projects that are grown up with ant. Avoid this stupid approach because it generates more problems. Instead stay with ant and its pain or migrate fully to maven.
If you are in doubt about the migration costs I suggest you to use the contrary way of integrating that different worlds by the Maven-Ant-Plugin. With this standard plugin you can run every ant-script without any effort. Sure it’s a legacy solution for a while, but it gives you as much time you need to understand mega-lines of monstrous distorted uncommented ant scripts of your predecessor.
And now you will praise the next advantage of maven: You need very less documentation of your configuration, because documentation is part of every maven-plugin you want to use.
So I confess I was a Maven-Antagonist.
I know that one advantage of Ivy is that it can use different kinds of repositories. Maven is typically very rigid in the format of the repository it will use. That's all I know.
I've just spent 2 days reading through the Ivy documentation and I have to say, USE MAVEN if you have any kind of choice. Ivy is complete and utter garbage as far as I can tell. I just wasted 2 days trying to incorporate it into my build and am cutting my losses now. Why?
Ivy is a half-assed attempt at dependency management
Ivy documentation is a total joke
Ivy examples and tutorial are useless
As soon as I introduced 'configurations' (read as maven profiles), Ivy started going bezerk downloading all sorts of junk I don't need then failing. The documentation for Ivy is an utter joke. Maven documentation in comparison reads like a dream. If you want an example of how impenetrable and badly written the Ivy documentation is, take a look at the reference page for configurations. These are an essential part of any build, but in Ivy they seem to be a badly designed after thought.