Maven javadoc plugin should be skipped by default but should able to execute when needed - maven

I want maven-javadoc-plugin to be skipped by default, during the
mvn clean install command, so I have added <skip>true<skip> in the pom.xml
But I want it to be executed whenever needed, so I am trying something like
mvn clean install -Dmaven.javadoc.skip=false But it seems that it is overriding this setting with that in pom.xml and not executing the javadoc plugin.
What can I do to resolve this problem?

You could create a profile for the plugin execution (move it from the normal build generation). Within the profile, simply state that the plugin should run when you want it. The idea is that when you do a run without the profile included in arguments, it won't run; if you include the profile argument, it'll be kicked off:
http://maven.apache.org/guides/introduction/introduction-to-profiles.html
Run arguments would look something like:
mvn groupId:artifactId:goal -P profile-1

Related

Generated code is not compiled

I wrote a Mojo that creates a new Java class and puts it in /target/generated-sources/annotations. in addition, I have configured build-helper-maven-plugin to declare that folder as source folder.
The problem is when I do: mvn clean install from CLI it generates the source file but it doesn't compile it.
Note, if I run Maven Install from within Eclipse (using the m2e connector) then it works fine.
What am I missing?
Without an actual plugin definition, we can only speculate.
I can't comment on m2e, I see one obvious difference that you state by yourself: mvn clean install vs mvn install, but from the "bare" maven's standpoint,
here is one possible reason:
Maven has a concept of phases that comprise the lifecycle. An information about phases of default lifecycle is available here
Plugins (more precisely the "goals" of plugins) are something that usually gets attached to a particular phase.
Maven compiler plugin is attached to the compile phase, for example.
So, maybe the plugin that you've developed runs later than the compiler plugin.
Usually, source generation plugins are attached to generate-resources phase.
Its possible to run a full lifecycle in maven, in fact its what people usually do, for example, running mvn test actually means, run all phases of the default lifecycle up-to (including) phase test.
It's also possible however to run a particular plugin goal "directly" without attaching it to the phase. Of course, in this case, its pre-conditions should be met.
For example, mvn surefire:test means that we should invoke the surefire plugin directly. Of course the source code and test code should be compiled beforehand (bytecode has to exist in the target directory)
So I suggest you to run the following series of commands (Adjust if you have tests):
Run mvn clean install on the plugin project to place it to local m2 repo
Run the plugin directly: mvn ::: and check
whether the source is generated in the target folder
Make sure in pom.xml of the project that the source folder are configured correctly
Run mvn compile (phase up-to, including, compile) on pom even without the plugin
After this phase, there will be compiled sources in the target directory. Don't run
clean because it will wipe out all the target directory
This will effectively help to make sure that plugin does the job right

Maven - Running mvn without arguments

Does running mvn with no arguments in the directory of the project result in the default lifecylce being executed for that project?
What if a profile is specified with the -P flag? does it execute the default lifecycle and binds any plugins in the profile to the phases they declare?
On your pom you can use the tag defaultGoal to specify the goal that should be executed by maven if you do not specify nothing on the command line.
See POM reference

Run mvn exec:exec without a pom.xml

I am trying to find a way just to fetch a library from maven repository and run it. I want to define everything by command line and ignore the pom. I am trying following:
mvn exec:exec -Dexec.mainClass="org.main.Class" -Dspring.profiles.active=test
When I try to run it with pom.xml, it starts to fetch all the dependencies described in the pom. Which I really don't want. When I run it without the pom.xml, it says Goal requires a project to execute but there is no POM in this directory. Please verify you invoked Maven from the correct directory. Is there a way to run it without the pom or at least ignore it?
My goal is just to start my application from anywhere without sources or jars.
One possible workaround would be to:
first get the jar
then execute it
For that, the maven plugin dependency:get is handy, and can be executed without any pom.xml/project (so from any folder you want)
mvn org.apache.maven.plugins:maven-dependency-plugin:2.1:get -DrepoUrl=https://dtp.intramundi.com/nexus/repository/maven-central/ -Dartifact=<group>:<artifact>:<version>
Once you have copied the artifact to the folder of your choice, a plugin like dependency:copy-dependencies could, reading the pom.xml of the artifact you just got, copy said dependencies to the same folder of your choice.
Finally, a java -cp . yourArtifact.jar can execute it.
I realize this is not as straightforward as just "exec:exec", and that it fetches dependencies from the pom.xml, but here at least:
the first step does not require any pom.xml,
the second step needs the pom.xml of the very artifact you want to execute, and those dependencies might be needed at runtime: you would need those anyway if you want to 'exec' your artifact.
Nope. It's impossible. Mvn Exec is, in fact, Maven Pluging dedicated to execute something as part of maven-nature project. If you need to execute Jar outcome why not use just java ***.jar ?

Why should run first mvn clean clover2:setup install clover2:clover, then: mvn sonar:sonar

Based on the question Sonar + Clover only runs on src-instrumented, it is suggested using first mvn clean clover2:setup install clover2:clover, then: mvn sonar:sonar.
Just wonder why we cannot use mvn clean clover2:setup install clover2:clover sonar:sonar?
In the past it was the recommended way to run goal sonar:sonar alone. This is no more the case since SonarQube Scanner for Maven stopped trying to run unit tests + collect coverage for you by forking a new Maven lifecycle.
General advice is now to run goals in a single command. For example mvn clean package sonar:sonar
In the case of Clover the clover:setup goal will alter the Maven Model to make all other plugins (like surefire) use instrumented classes instead of original source code. This is indeed a problem because it will prevent SonarQube to match class files. So in your case you should either stick with two separate goals, or manually configure sonar.sources to refer to original source code.
Compared the maven logs and found the possible reason:
The "mvn clean clover2:setup install clover2:clover sonar:sonar" seems having issue to find the Source dirs. The log shows it uses ${project}\target\clover\src-instrumented and ${project}\target\generated-sources\annotations as the source dirs.
If explicitly specify src/main/java, then this single command works well. The only tricky thing is why running the goals separately doesn't need to specify sonar.sources but the plugin can still find the right folder for source dirs.

Maven plugin execution change Maven properties or skip build lifecycle steps

When I build my application with maven, I run mvn clean install. As a part of the install lifecycle, I run appengine:devserver_start from Google's GAE Maven plugin. This appears to be already bound to a step in the lifecycle and therefore it reruns some build steps from the beginning, even though me running mvn install did those. For example, the resources step is rerun. I had my own Java script run to download the latest resources for my build. But because of appengine:devserver_stop, I need to uselessly run this cript again because the resources step is re-executed.
I can think of two ways I can avoid this, but I'm not sure how to configure both ways. The first would be to somehow skip re-running build steps that I've already run. The other way would be to change the Maven POM properties just for the plugin execution. I have a Maven property set, either to true or false, that I can use to set the skip setting for the Java script I use during resources (because I run this script using the exec-maven-plugin). Think of this as a Maven property that can be set with the -D flag. Can I have this property changed just for the plugin?
If you are having trouble thinking about my scenario, consider what happens when you run mvn compile install. All build lifecycle steps until compile will run, then all compile steps until install will run, including compile.
A common/easy way to solve this kind of problems is to use maven profile. Just create a new profile that includes the plugin with preferred phases.
You should probably don't fight with it and just run clean appengine:devserver_start instead of clean install. Read my answer here for a more detailed explanation:
https://stackoverflow.com/a/17638442/2464295

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