I have a GWT webapp split into two Maven projects where one is a dependency to the other. Each time I change something in the dependency and I'm running webapp in hosted mode I have to rebuild the subproject and restart hosted mode for changes to apply. It takes a lot of time so I'd like to ask you if there is any way to make GWT using "live" version of the dependency?
There are 2 cases:
for server-side code, assuming you use the DevMode's embedded server, rebuilding the app and then refreshing the server should be enough
for client-side code, AFAICT, you have to use the source and output directories of the dependency module rather than the JAR containing them (GWT will load the source from the classpath, but apparently it'll only see the modified sources if it comes from a folder rather than a JAR; at least that's what I found in my tests). This goes against The Maven Way™ but the only solution so far is to use a special profile that will import the sources of the dependency project as sources of the project you're running. You can see examples of that in my archetypes.
There's actually a bug opened for the gwt-maven-plugin, MGWT-332, to do that automatically when running a reactor build. I also mused about what's really needed, for the forthcoming official gwt-maven-plugin (rewritten from scratch, independent from the CodeHaus Mojo plugin).
If your dependency does not come from a reactor build, then you're out on your own: you chose to make it totally distinct, so that's how it'll behave: you'll have to release it (even a snapshot) each time you make a change to it, and use the new version in your app (which means re-launching the DevMode).
This can be circumvented by running DevMode on your own, without the help of the gwt-maven-plugin. You're left on your own managing the classpath though (using the Google Plugin for Eclipse, I suppose you could simply edit the launch configuration to add the source folders of your dependency project to the classpath, before the classpath provided by Maven, that would reference the JAR).
Remove the dependent other application jar file from the primary application lib folder under webapp.
Eclipse should then resolve the dependency using the other project in the workspace if you have added it to your primary application classpath.
As GWT build takes ages, we invested some money in a JRebel license. We have two separate Eclipse projects for our back-end and our GWT front-end. JRebel reloads the classes automatically and I never need to restart my local server while writing code. It proved to be a wonderful time saver. Definitely worth the investment.
Related
I had a NoClassDefFoundError problem with some test, launched from IntelliJ. In order to repair the situation, I had to make several changes in many poms of the project - adding new packages and excluding some old ones for to escape the overlapping of them. Also, I reapired the situation with different versions. But the situation did not improve. Again, some package, declared in pom, was not found where it should be.
I refreshed the maven repository by
mvn -e clean install -U
, as is advised in https://stackoverflow.com/a/9697970/715269 - so old and upvoted answer, that it surely looks as Santa.
The problem remained unchanged.
I output the maven map. It was correct and it contained all needed.
I looked at the list of the External Libraries of the project. It was the old uncorrected list of overlapping jars with same names and different versions, and without good packages I added just now, and well seen in maven tree output!
Already hapless,
I reimported packages in IntelliJ
by:
Ctrl+Shift+A, Reimport All Maven Projects.
Ho! The list of libraries got repaired. And the problem, mentioned in subj, disappeared.
The question is: How it could happen, that the same project has that very pom for everything, but gets packages differently being launched in maven and in IntelliJ?
I know about that feature "delegate IDE build to Maven". And I keep it turned off. But I am NOT talking about the different SW for building. Whether they are different or not, they should be up to the actual pom's. And whereas maven, if turned off from the automatic building won't know about changes in poms, IntelliJ KNOWS about them. It could have jars up to pom, or up to maven - it has sense, but it simply has some old rubbish. Was there some deep thought under that construction?
Every time you manually change the pom.xml file, including the dependencies you need to load these changes into IDE. IDE does it on Reload from Maven action. See also Import Maven dependencies.
Intellij doesn't use maven to bulid and run a project except you are delegating build and run action to maven:
Since, IDEA doen't really use maven to run and build, it uses the pom.xml to import the project structure and "tries" to build the project the same way was maven does.
Actually, there are quite a few differences between these to build processes.
Generating sources or filtering resources (don't know if this is still an issue) aren't done during building the project with Intellij IDEA.
In case you are using code generation you have to build the project via maven first and then - when all the resouces are filtered and additional sources are generated - you are able to run, debug aso. the project with Inellij IDEA.
That's an important thing to be aware of and that's the reason why maven and IntelliJ IDEA project structures might get out of sync.
You can enable the "Reload project after changes in build scripts" feature and select the Any changes checkbox to keep your project structure updated:
Why should you disable this feature anyway
If you are working on a build file (gradle or maven is not important) reloading the structure on any change can be very anoying. It's cpu intense, dependcies are fetched aso.
Therefore, I prefer to reload project structure only in case of an external change. This happens when pulling an updated version of the build file for example.
I am a total beginner at maven, I have read about it online but I am still confused how it can be used. I have eclipse Oxygen version installed and when I open projects I can see maven project option is already there. I was even able to create a maven project using YouTube tutorial. But now then I saw popular plugin called m2eclipse but I am not able to comprehend why is it actually used; when my application ran without it.
I am learning maven to get started with spring boot but I am finding it really overwhelming where to begin with, and many of the tutorial sites state to download maven (But maven already comes along with eclipse?)
Please explain.
Apache Maven is a build tool - a tool for compiling the source code of a project into a program that you can run (for example a jar file, or a war file that can be deployed on a Java EE application server). Besides automating all the tasks for building a project, it also gives you a standard way to organize your project and to keep track of dependencies (libraries that your project needs).
Why do you need such a tool?
When you write a small program that consists of one, or maybe a few source files, it's easy enough to compile it by hand on the command line, by directly using the Java compiler javac that comes with the JDK.
But when your project becomes more complex, and you have hundreds or even thousands of source files in multiple modules, it becomes really hard to keep track of everything and cumbersome to compile the files using javac. If your program needs libraries, it becomes even more complex, because you have to make sure that all the libraries are on the classpath, and some libraries need other libraries, which also have to be on the classpath.
A tool such as Maven helps you to compile all the source files in the right order and to keep track of all the libraries. Maven can automatically download libraries from the web and add them to your project, and downloading everything and building the whole project can be done with one simple command such as mvn clean package.
Spring Boot is part of the Spring Framework, which is a huge framework with tons of useful functionality for developing projects in Java. A Spring Boot project typically needs dozens of libraries, and it would be very hard to use if you'd have to keep track of all those libraries by hand - so that's why it uses Maven to manage all of this for you.
A Maven project is configured using a file named pom.xml - in that file, you describe your project and you put a list of libraries that your project needs. When you build your project, Maven will read the pom.xml file and figure out automatically what source files need to be compiled, and what libraries need to be downloaded.
m2eclipse comes preinstalled in Eclipse (at least when selecting "Eclipse for Java developers" or "Eclipse for Java EE developer"), thats why you were able to use Maven by default.
Still you probably want a command line Maven, because that's most likely how it will eventually run on the CI server, sometimes Eclipse Maven installation can produce different result than the command line install.
I am in the processing of integrating Maven into my my projects. While maven has plenty of pros i'm finding it difficult to figure out how to maintain my current development process, which is as follows:
For creating SDKs I will create a sample app, which will depend on and directly reference the SDK source code, all from within the same code project. This means that I can make easily change/debug the SDK code with one click run/debugging.
I fear this won't really be possible with Maven. Can I create some type of Hybrid approach, where I continue my normal development approach and then push builds to Maven when it is appropriate.
Update - For Clarity
My problem is that when everything is done through maven, the dependencies are built and published to Maven. Then, the dependent project pulls down compiled references and uses them. My issues is that I don't want to go through this whole process every time I make a small change to a dependency.Thanks.
You should try creating parent level pom.xml with two modules - your library and simple app to test it. In simple app's pom.xml provide a dependency on library module.
Then open in your IDE parent pom as maven project. This should be sufficient for normal debug.
Other possible approach - install you library artifact into maven repo with sources. In this case you will be able to debug it, but test app still have to load use jars from repo.
Hello all !
In my team we currently use Eclipse but I am not satisfied and I wanted to discover netbeans (8 version). It seems very nice. There is a good management of webprojects( angularJS, requirejs). There is a full integration of maven project and Java EE project, it's free ( not like intelliJ) and it seems more intuitive than eclipse et less strange/magic , more compréhensible (because full integration of maven)
There is a lot of points who could push my team to adopt this IDE but there is a problem,a need that I can not satisfy.
I have maven modules projects with dependency mangement. A parent project (called 'webParent' that contains a reference of a big parent project of the team. 'webParent' also contains a sub project 'WebProject' that is a java Webproject that contains web resources( html, js, css) and a java rest webservice management.
'WebProject' use service by injection dependency of an other project called 'business'. 'business' is a part of an other parent project called 'core'. 'core' contains modules that are 'business' (business services of application), 'dataAccess' (gather all DAO), 'External' (gather all external webservice) and 'Authent' (authentication ..).
All these core modules are linked.
'business' need => 'dataAccess' , 'External', 'Authent'
'External' need => 'dataAccess'
'Authent' need => 'dataAccess'
Netbeans has perfectly integrated my project, no problem with that.
I could perfectly use my previous jboss install. Netbeans and jboss work perfectly together. but my problem is that my modifications are not take in account by jboss on redeploy.
I have installed this plugin in my webproject https://docs.jboss.org/jbossas/7/plugins/maven/latest/
Indeed it work fine. When I need to redeploy my project I launch jboss-as:redeploy and a war is regenerated and sent to jboss. Jboss restart speedly and it's cool. But if I modify the java code
in my sub-modules (ex: business) I am forced to click on build button (the hammer) on each sub project I modified. Wait that build say "nothing to compile (indeed the compile on save is checked for all project), regeneration of the jar module"
And I stop on this detail. The "jar". Indeed when I verify my local repository my module jar is not changed with compile on save, it's just the target folder of the project that is modified.
So when I launch the redeploy, the plugin launch the build of my webproject who search my modules jars on my local repository. And take a version not modified ..
This problem slowed a lot the developpement and because of it my team will never use netbeans in the future..
The other problem is that I am forced to lauch jboss-as:redeploy to redeploy web ressource (html, css, js) . For me its should be automatically repercuted on my server. But the problem is that jboss use a war that is generated on install.. What's the solution ? With eclipse it's not based entirely on maven (not cool) but the repercution of modification is very speed ( cool)
Help me to stay on netbeans ! ;)
Why there's a difference in Default Source Lookup Path between GWT and java launch configurations?
In multi-module projects instead of containing projects, the Default folder contains the class folders of those projects!
It causes "Source not found" errors when the debugger steps into a dependency project.
I know I can add projects manually. Just want to know why this difference is needed.
The only project in the list is the associated with the .launch.
GWT needs '.java' source files of dependencies to be able to compile (translate to js) while the Java launcher needs only '.class' compiled files.
I suppose you know GWT has a different way to manage dependencies (through modules within the same project), which is good for some advanced GWT practices like loading a module's js lazily (this feature doesn't work with "foreign" libs/projects).
So this could also be an answer for why eclipse GWT doesn't suppose you will have more projects (but more modules instead)
Finally if you really have an independent GWT lib that you're maintaining this is an issue as you said.