I was going through the maven documentation. I saw maven works using plugins, for each phase there is one or more plugin and for each plugin there is one or more goals. there are plugin for compile, install, deploy, clean etc. I saw in my project they used maven-clean-plugin. Then how maven clean install command is working if we did not put the maven-install-plugin? Question might be bit silly but i am new the this world and appreciate your help.
That would follow up with some default configuration of each plugin inherited with Maven's BOM. Executing
mvn dependency:resolve-plugins
shall help you identify these versions of the plugins inherited.
So primarily to ensure you work with a specific(or updated) version of the plugin with the desired configuration of your project, you can explicitly define them in the pom.xml, otherwise, just let be.
The Maven lifecycle has standard bindings for plugins to the different phases.
If you run mvn clean install you run the plugins that a attached to the phases by default.
Related
The solution which needs bootstrapping is supplied as java code. Absolutely sure that this is necessary.
Receivers of the solution are guaranteed to have a suitable JDK
However, receivers of the solution are unable to install Maven (they don't know how to and cannot be taught)
My idea is to include some sort of Maven with the project, such that can be set up in a script like so:
set up maven repo as a folder under the solution folder (using relative reference)
set up anything else maven needs (don't know what, exactly)
call /path/to/maven/mvn compile -f /path/to/oneAndOnly/pom.xml
java /target/MySolutionClas
I am aware of: https://dzone.com/articles/embedding-maven but it gets confusing when he talks about configuring the portable maven into the pom.xml - wait, how is that pom.xml going to mean anything if maven is not configured yet?
(PS: I mean no disrespect to the author. I probably got it all wrong)
One could include a shell script that would setup maven if it is not already present.
The same for building and packaging encapsulating the complexities of the setup to just runing a couple of scripts.
Maven Wrapper aims to do just that, similar to the gradle wrapper seen in many gradle projects.
Running the wrapper goal of the maven wrapper plugin will generate a mvnw script in your project that can be run in place of a globally installed mvn command.
It's part of the maven 3.7.0 release, and documented more fully here: https://maven.apache.org/plugins/maven-wrapper-plugin/index.html
See https://github.com/takari/maven-wrapper for maven < 3.7.0
From what I read, maven cycles through the lifecycle phases and goals invoked through the command line and it simply cycles through the mentioned phases and goals. The defaults in pom.xml make sure that maven runs sensible defaults by always running a series of plugin goals according to packaging using default bindings.
Also, if I only and only want to download dependencies and do nothing else, I can call mvn dependency:generate-sources.
So my question is:
If we run mvn install, it also downloads the dependencies mentioned in the pom.xml? Does this happen because calling install calls all the phases up till install including generates-sources which is bound to dependency plugin by default?
If not, who is responsible for fetching all the dependencies? Maven core or some other plugin?
If yes, the list of plugins invoked by default does not seem to be exhaustive. What other plugin bindings exist in pom.xml?
Yes
N/A
All maven projects have, at their base the "Super POM" which lists all of the defaults for maven. You can look there for everything. This "Super POM" is placed as the parent for any POM that doesn't list a parent explicitly.
I am new to Maven and I faced a problem when I tried to convert my current project from using Ant -> using Maven.
That project requires many Jars, and I look up those jars on mvnrepository and add all to POM.xml.
I don't know if some dependency is redundant.
Do you guy know any way to check if which dependency which I really need?
The Maven dependency analyzer plugin is just what you're looking for.
Just run
mvn install dependency:analyze
(on some platforms, for some reason, the full notation is required:)
mvn install org.apache.maven.plugins:maven-dependency-plugin:2.9:analyze
And review the report it produces.
I have the same problem like on the below link , and solution from there works
but i have a little of hard time in understanding what it cause this and how it affects the project.
Plugin execution not covered by lifecycle configuration (JBossas 7 EAR archetype)
I start reading about m2e
http://wiki.eclipse.org/M2E_plugin_execution_not_covered
What is the difference between the 'eclipse build' and maven one ?
Still not clear what is meant by "interesting" and "not-interesting" mojo executions:
https://docs.sonatype.org/display/M2ECLIPSE/Project+build+lifecycle+mapping
So there is the solution but , not the understanding of the problem.
Thanks for helping me understand the problem ...:)
Generally speaking, The way m2e used for resolving/mapping plugins' goal execution into Eclipse build life cycle has been reinvented after version 0.12. Now m2e requires explicit instructions what to do with all Maven plugins bound to "interesting" phases of a project build lifecycle. By either configure the lifecycle mapping in your project's pom, or use specific m2e configurator Eclipse plugin if somebody has kindly created it for the community.
By "interesting" they mean phases which normally occur during writing and debuging of code inside the IDE, mostly excluding packaging and deployment steps.
Also note (from this blog post):
M2E allows you to run Maven manually. You can invoke a goal like "mvn install" from within Eclipse just as you would do it from the command line. That works (and always worked) just fine. Unfortunately, Maven is also invoked automagically from M2E whenever Eclipse builds the project, for example after a clean. In such cases M2E acts as an "Eclipse Builder". It is these latter invocations that people have always had problems with and that the connectors should handle better.
When Hudson goes to build my project, it executes Maven as follows:
Executing Maven: -B -f /path/to/root/pom.xml clean install
This works fine on most projects. (The -B is for "batch" or "non-interactive mode", BTW).
But for this one project that uses AndroMDA (which I can't recommend for future projects, it's really a pain-in-the-butt; slows down the build by 1000% with code generation for things that could be trivially done with inheritance and annotation-based config).
For some reason unbeknown to me, when Maven is given the -B flag the generated classes are no put on the classpath causing compilation errors for references to the generated classes. I've tested building manually with -B and without it and the result is that it builds fine without -B (outside of Hudson) and it doesn't build with -B (again, outside of Hudson).
Using Hudson version 1.369 and an external Maven 2.2.1 install.
Any advice greatly appreciated!!!
P.S. Hudson is AWESOME!!!!
The simplest version would be to have a free style project, and call maven yourself.