spring-boot-devtools doesn't reload dependent modules in multi-module maven project - spring

Before I start, I'd like to say that I already tried the solution proposed in spring-boot-devtools reload of multi-module maven project changes, which didn't work for me.
Problem:
I have a multi-module Spring Boot project of this sort:
The module launcher has a Maven dependency on module GUI. I launch my Spring Boot application from the main method in launcher.
When I run the application and change any HTML file in GUI module, the spring-boot-devtools dependency doesn't do a live reload of these changes for my running application. Not even manual restart of launcher helps. I need to compile GUI manually and then run launcher again.
What I tried:
I tried defining the spring-boot-devtools dependency first in
parent pom.xml, then in GUI module only and then in both at the same time.
I tried adding spring.devtools.restart.additional-paths=../gui in my application.properties file as suggested in spring-boot-devtools reload of multi-module maven project changes. This does indeed trigger the reload (according to the log), but those changes just don't propagate to the jar file of GUI dependency. Also, before I even made this project into multi-module, there was no need for reloading just because of HTML files (nothing is being compiled) and I could see the changes right away.
I use Netbeans GUI if that's of any help. I also tried running the project from command line, with no success. The Maven packaging on all modules is set to jar.

The fact that this works when you configure absolute paths in devtools tells me that this is mainly a work directory issue.
So this means that:
configured paths should be relative to where you launch the CLI
you should configure the same location as a work directory in the run configuration of your IDE (whatever configuration your IDE is using to launch your application should have such an option)
In your case: everything should be relative to your launcher module; this should be as well your work directory in your IDE.

I have no idea how it happened, but upon one revisit it started working without me knowingly changing anything. It doesn't even require the spring.devtools.restart.additional-path property set.
Could've been a problem of Netbeans IDE perhaps? Then again, it didn't work from command line either. If anyone has any explanation for this, it'd still be grateful as it may prevent this problem from happening in future.

Related

Modules, Gradle Subprojects, and IntelliJ Woes?

I am trying to make use of modules and gradle subprojects and either receive compile time errors or complaints from IntelliJ.
My project structure is as follows:
Root
- settings.gradle
- core
- build.gradle
- desktop
- build.gradle
- src/main/java/module-info.java
The desktop build.gradle file as a requirement on core as:
dependencies {
implementation project(":core")
}
There is no reference to the "core" project in the module-info.java files.
In this configuration, IntelliJ doesn't like usage of classes from the "core" project in the "desktop" project (I see a lot of red), but running gradlew.bat desktop:run works with no issues. Bug with IntelliJ? I am using microsoft's openjdk, but hopefully that doesn't matter.
My best attempt to fix this, was to add a module-info.java file to the core project as well and reference the core project in the desktop project's module-info.java file. Unfortunately this configuration, while making IntelliJ happy, renders me unable to run the desktop from command line anymore. I get errors about the core project being unable to find required modules that are the exact same as the required modules I pull in for the desktop module. I think this might be an error on my part, but I'm not sure how or what to do to fix it.
Would appreciate any insight.
P.S. Of these issues, I think I would prefer to get IntelliJ working with the first setup, because I intend to have this core library be shared between the desktop project and an android project, and while I haven't looked into it yet, I am not sure Android supports new java modules?
I think terminal should be the first priority. If your original setup made it compiled successfully under terminal, then there is no problem in your project. Do not add extra files for just making the IDE happy.
There's still something you can do. The first step is compiling your project successfully under terminal. This step downloads all the necessary dependencies before IntelliJ, reducing the problem scope to IntelliJ's linking and indexing. Then there are some options:
In the Gradle tool window, click the top-left button Refresh all Gradle projects.
Delete all the .idea folders in your project. Then open the root folder of your project via UI or CLI.
Click the invalidate caches/restart in the main menu.
You can also also create a new Gradle multi-module project with command gradle init, and open it with IntelliJ. It should be analyzed by IntelliJ normally. Then you can compare its project structure with yours. Maybe there's something different.
Hope these steps could help you.

Why refresh of Maven repository is not enough for IntelliJ?

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.

Netbeans does not always update target/classes/*.class file on incremental compile on a Maven project

I use Netbeans 9.0 with a Java Maven project with SpringBoot 2.1M4.
The application is running in a terminal window with Spring DevTools enabled so that it reloads every time a .class in target/classes is touched.
This setup generally works fine. Problem is, that sometimes, I notice that Netbeans stopps actually updating the class files. I change the source, save, have of course "compile on save" activated but a find target/classes -name "Foo.class" continues to show the old timestamp so DevTools have no chance to notice the change.
A complete build on the other hand executes Maven and that, of course, regenerates the target/classes files as expected.
Is there any mechanism in Netbeans that I'm not aware of that controls how the Netbeans "incremental compile" affects the class files?
(I experienced similar problems before with Netbeans 8.2 and various application servers or DCEVM/HotSwap, which also monitor file changes)

Intellij Debugging picking up old version project files

I am debugging code in Intellij. I use maven to build the project and there are various versions of the project sitting in the local .m2 repository. Intellij keeps on picking the old version of the code from the previous snapshot of the project when I start debugging. How do I make IntelliJ debug the latest code from the local repository?
You can tell Intellij 2016 to ask you each time which source code to step through.
File->Settings->Debugger
Show alternative source switcher
Try removing .jar and .war files that contain your code from your ~/.m2/repository/
For me the issue is that I built something and it is now registered in Maven under what Maven considers a newer version, but isn't what I was currently working on. I compiled, say, version "2.1" to debug something and then went back to working on "sand-box-idea-SNAPSHOT". I keep thinking why isn't Intellij picking up my latest sand box change but it's because it's deferring to the Maven version 2.1 which Maven assumes is better than 'sand-box-SNAPSHOT'.
It may be that you have some plug-ins interfering with IntelliJ's build process. I know that the Google Protocol Buffers Plugin can cause my Intellij to be unable to detect dirty classes that need to be re-compiled.
I've met similar behavior, maybe it can help you :-)
I developed app (using maven) and during the time I change output packaging from jar to war. Maven repository than contained both versions, jar and war, because maven does not remove old jar when you change it. As project pointed to mvn repository, it still used old reference to jar but new version within war was updated.
I was really upset as maven compilation and tests worked fine but Idea used me old version. I've had rebuild idea project and it worked later fine.
I have seen this very recently after upgrading from IDEA 13 to IDEA 14. It seems like launching configurations created in IDEA 13 are no longer automatically triggering a mvn package prior to launch.
In order to fix this I manually added a mvn goal in the "Before Launch" dialog.

Update dependencies while in hosted mode in GWT

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.

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