Does maven-release-plugin also do what maven-compiler-plugin does? - maven

In project pom.xml is it required to include both maven-release-plugin and maven-compiler-plugin? The reason I want the release plugin is because I want to release the project at the end of a sprint/release. I understand that the compiler plugin will compile the source code, however I am not sure if the release plugin will also compile the source code, apart from updating the pom and checking out/in to scm.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.2.2</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
Any help with this is much appreciated.

If unspecified, Maven will know what to do when it needs to compile the code. However, in order to be able to control things like source and target versions, you will need to have a declaration of the maven-compiler-plugin.
It is generally good practice, to explicitly define the plugins you are using, along with their configurations and above all their versions, so that you have a guarantee of what was working.

What the Maven Release Plugin does is described here.
Your question is about the bullet "Run the project tests against the modified POMs to confirm everything is in working order". There is not that much magic here. What happens is that the maven-release-plugin will start a new Maven session. It will execute "mvn verify" in the same folder where you ran "mvn release:prepare".
All the steps done by the maven-release-plugin could also be done by hand, but that's asking for mistakes.

Related

Pomless Tycho build + maven release plugin

I have a pomless tycho build which I want to release with the maven release plugin. The issue I have is that I get errors from the git plugins for the generated .polyglot.build.properties even though it is not included in the configuration of the git-add goal.
Parent pom.xml:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.5.3</version>
<configuration>
<autoVersionSubmodules>true</autoVersionSubmodules>
<localCheckout>true</localCheckout>
<preparationGoals>
org.eclipse.tycho:tycho-versions-plugin:${tycho.version}:update-eclipse-metadata
build-helper:parse-version
org.apache.maven.plugins:maven-scm-plugin:1.9.5:add
org.apache.maven.plugins:maven-scm-plugin:1.9.5:checkin
</preparationGoals>
<completionGoals>
org.eclipse.tycho:tycho-versions-plugin:${tycho.version}:update-eclipse-metadata
build-helper:parse-version
org.apache.maven.plugins:maven-scm-plugin:1.9.5:add
org.apache.maven.plugins:maven-scm-plugin:1.9.5:checkin
</completionGoals>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-scm-plugin</artifactId>
<version>1.9.5</version>
<executions>
<execution>
<id>default-cli</id>
<goals>
<goal>add</goal>
<goal>checkin</goal>
</goals>
<configuration>
<includes>**/META-INF/MANIFEST.MF,**/feature.xml,**/*.product,**/category.xml,release.properties</includes>
<excludes>**/target/**</excludes>
<message>Changing the version to reflect the pom versions for the release</message>
<pushChanges>false</pushChanges>
</configuration>
</execution>
</executions>
</plugin>
The error I get:
fatal: pathspec 'my.plugin/.polyglot.build.properties'
did not match any files
After looking at the source code of tycho-pomless, polyglot, and maven-release, I conclude pomless build can't work with maven release. I need to add pom.xml
The reason is:
tycho-pomless uses polyglot, which creates an temporary pom from the build.properties, which is deleted when the JVM exits
maven release:prepare spawns a child maven process to execute the preparation goals. When the child process finishes, this deletes the temporary files. The available mavenExecutorId values are "invoker" which invokes a new process, and "forked", which forks the process. Which means both spawn a new JVM.
So in conclusion, it looks like tycho-pomless (or any polyglot build, really) and maven-release are incompatible in the presence of preparation goals, and there seems to be no workaround. The possible workaround of executin the preparation goals in the same JVM seems to be unavailable. So the solution is adding a pom.xml
Check first is this is similar to this question, where the plugin does finds the files it should add, but, when creating the command line, it does not respect the correct root directory.
See if the path mentioned in pathspec 'my.plugin/.polyglot.build.properties' the correct one.
Double-check if your POM and folder hierarchy is at the right place, meaning in the project root folder.
The OP kutschkem refers in the comments to:
the .polyglot.build.properties is a temporary file, deleted by the release:prepare child process exit.
But release plugin picks it up as the pom of the project to checkin.
That might be why I see in Tycho/Reproducible Version Qualifiers
<jgit.ignore>
pom.xml
.polyglot.build.properties
</jgit.ignore>

Confusion on maven compiler plugin

I am quite confused about maven compiler plugin and what it does. I have a project that has several modules. In my top pom.xml I have a section
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<inherited>true</inherited>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
My understanding is this specifies the JDK compiler version used to compile the code, and this section get inherited by all the modules. What I don't get is in my IntelliJ IDEA I can still specify project JDK in the settings and it seems like that setting overrides this. When I run maven install in the IDE I can confirm that it is using javac from JDK 8 to compile. So what does this section do exactly?
You are correct; maven-compiler settings should be inherited by child modules.
I don't know about IntelliJ, but I can tell you that Eclipse picks&chooses whatever it wants from maven config, and for all the rest it uses its own settings.
Therefore, I'd expect IntelliJ may do something similar?
The simplest way to test this is to run a mvn clean install via command line, and see which "wins". If you get artifact compiled with 1.8 then it means you're missing something in Maven config which causes those settings not to propagate to children. If you get artifact compiled with 1.7 then it is IntelliJ who does it and not maven-compiler-plugin.

Maven + AspectJ/SpringAOP + Lombok + Surefire = test broken in a specific scenario

I have an interesting problem in a project where all of the technologies mentioned in the title are used. I've been able to track it down up to the diagnosis (the test classpath prepared by Surefire), but I don't understand whether it can be fixed and how. It's not a showstopper, indeed it's a minor issue for me, but I'd like to solve it anyway.
First a rough description.
The problem is related to executing tests in a specific module of the project, and only in a specific way.
Everything works (tests pass) when I run from the master pom level:
cd ${projHome}
mvn install
Everything works (tests pass) when I run:
cd ${projHome}/modules/CoreImplementation/
mvn test
That means that I can build and test with no problems, the same for my Jenkins, and NetBeans can run tests from the IDE when I need them.
But that module fails testing when I run from the master pom level:
cd ${projHome}
mvn test
with this error:
java.lang.NoSuchMethodError: it.tidalwave.northernwind.profiling.RequestProfilerAspect.aspectOf()Lit/tidalwave/northernwind/profiling/RequestProfilerAspect;
at it.tidalwave.northernwind.frontend.ui.spi.DefaultSiteViewController.processRequest(DefaultSiteViewController.java:82) ~[classes/:na]
at it.tidalwave.northernwind.frontend.ui.spi.DefaultSiteViewControllerTest.must_call_some_RequestProcessors_when_one_breaks(DefaultSiteViewControllerTest.java:161) ~[test-classes/:na]
Running mvn test as a second pass (after a mvn install -DskipTests) happens to be the way Drone.io and Travis do their job. While I could change their configuration, I'd like to stay with the standard configuration and fix the problem if possible.
The diagnosis in short and my question.
Now, the question in short (details are further below). I was able to track down the problem to different ways in which Surefire prepares the classpath to execute the tests.
When I run mvn install the classpath is:
${repo}/org/apache/maven/surefire/surefire-booter/2.16/surefire-booter-2.16.jar
${repo}/org/apache/maven/surefire/surefire-api/2.16/surefire-api-2.16.jar
${projHome}/modules/CoreImplementation/target/test-classes
${projHome}/modules/CoreImplementation/target/classes
${projHome}/modules/Core/target/it-tidalwave-northernwind-core-1.1-ALPHA-37-SNAPSHOT.952b0c8bdc77.jar
${repo}/it/tidalwave/thesefoolishthings/it-tidalwave-role/3.0-ALPHA-1/it-tidalwave-role-3.0-ALPHA-1.jar
${projHome}/modules/Profiling/target/it-tidalwave-northernwind-core-profiling-1.1-ALPHA-37-SNAPSHOT.952b0c8bdc77.jar
${repo}/org/apache/commons/commons-math3/3.0/commons-math3-3.0.jar
…
When I run mvn test (from the project home) the classpath is:
${repo}/org/apache/maven/surefire/surefire-booter/2.16/surefire-booter-2.16.jar
${repo}/org/apache/maven/surefire/surefire-api/2.16/surefire-api-2.16.jar
${projHome}/modules/CoreImplementation/target/test-classes
${projHome}/modules/CoreImplementation/target/classes
${projHome}/modules/Core/target/unwoven-classes
${repo}/it/tidalwave/thesefoolishthings/it-tidalwave-role/3.0-ALPHA-1/it-tidalwave-role-3.0-ALPHA-1.jar
${projHome}/modules/Profiling/target/unwoven-classes
${repo}/org/apache/commons/commons-math3/3.0/commons-math3-3.0.jar
…
The different portions are the indented ones. In the former case, SureFire uses the classes directory (forget for a moment that in my case they are named unwoven-classes) only for the module under test, and the installed jar files for every dependency. In the latter case, it seems to be using classes for all dependencies in the reactor.
The reason for which this difference in the classpaths gives me troubles is explained below in the "Gory details" section. In short, that unwoven means that they contain bytecode not augmented by AspectJ, hence the methods that can't be found at runtime.
I'm running with SureFire 2.16, but I've also tried the latest 2.19 with no changes. Being able to force SureFire to always use jar files for dependencies would fix my problems. If you have the answer, you can stop reading my post here.
Gory details (just for curiosity).
The faulty module artifactId is it-tidalwave-northernwind-core-default and it depends on aspects available in it-tidalwave-northernwind-core-profiling - that's where the offending RequestProfilerAspect is. The aspect library dependency is both in the regular dependencies of the faulty module and in the configuration of the aspectj plugin:
<dependency>
<groupId>it.tidalwave.northernwind</groupId>
<artifactId>it-tidalwave-northernwind-core-profiling</artifactId>
</dependency>
...
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>aspectj-maven-plugin</artifactId>
<configuration>
<aspectLibraries combine.children="append">
<dependency>
<groupId>it.tidalwave.northernwind</groupId>
<artifactId>it-tidalwave-northernwind-core-profiling</artifactId>
</dependency>
</aspectLibraries>
</configuration>
</plugin>
</plugins>
</build>
AspectJ integration is by means of the following profile in a Super POM, which is activated in the build, whose relevant part is:
<profile>
<id>it.tidalwave-aspectj-springaop-v1</id>
...
<build>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<executions>
<execution>
<id>default-compile</id>
<phase>compile</phase>
<configuration>
<outputDirectory>target/unwoven-classes</outputDirectory>
</configuration>
</execution>
<execution>
<id>default-testCompile</id>
<phase>test-compile</phase>
<configuration>
<outputDirectory>target/unwoven-test-classes</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
...
The aspectj plugin is configured in the profile to statically weave binaries in the unwoven-test-classes directories. The reason for this approach is that it's the only feasible solution AFAIK to have both Lombok and AspectJ work together.
Now, back to the two classpaths described above: the fact that SureFire is using unwoven-classes means that it's pointing to bytecode that has not been augmented with AspectJ methods, hence the error.
References
The project is a FLOSS one and can be found at
https://bitbucket.org/tidalwave/northernwind-src
or
https://github.com/tidalwave-it/northernwind-src
A changeset where the problem can be reproduced is f98e9a89ac70138c1b6bd0d4570a22d59ed71be6. JDK 1.8.0 is required to build the project (even though it doesn't use Java 8 code yet).
The SuperPOM can be found here:
https://bitbucket.org/tidalwave/thesefoolishthings-superpom-src

How do I write a maven plugin which actually runs?

The instructions here seem very clear:
http://maven.apache.org/guides/plugin/guide-java-plugin-development.html
However, the first problem I run into is that the dependencies are wrong. I also needed to reference the maven-plugin-annotations dependency.
Then, when I attempt to run I get the "No plugin descriptor found at META-INF/maven/plugin.xml" error. I haven't figured out what to do about that.
I've found lots of pages referencing the maven-plugin-plugin, but I can't figure out how to add it to the pom so that it actually does anything which allows my own plugin to run.
Is there an updated version of the plugin development instructions which actually mentions the need to use maven-plugin-plugin?
If I can't get this to work I'm just going to go back to using exec-maven-plugin. It's uglier, but at least it works easily.
There are actually several terrific resources from Sonatype for learning how to write plugins:
Maven the Complete Reference: Writing Plugins
Maven Cookbook: Creating an Ant Maven Plugin
Maven Cookbook: Writing Plugins in Groovy
If I recall correctly, you need to configure the maven-plugin-plugin this way to avoid the "No plugin descriptor found..." issue.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.2</version>
<configuration>
<!-- see http://jira.codehaus.org/browse/MNG-5346 -->
<skipErrorNoDescriptorsFound>true</skipErrorNoDescriptorsFound>
</configuration>
<executions>
<execution>
<id>mojo-descriptor</id>
<goals>
<goal>descriptor</goal>
</goals>
</execution>
</executions>
</plugin>
I forked a simple GitHub project called maven-wrapper (port of the Gradle wrapper) to make it a Maven plugin.
"It should be easy" for you to figure out pieces that you may eventually be missing:
Maven wrapper plugin(Mojo)
Maven Wrapper full POM

Maven Site Lifecycle

So every bit of documentation I've been able to find about Maven and it's lifecycle says that site only has 4 phases:
pre-site
site
post-site
site-deploy
However, in my pom.xml I have an ant script that gets run on the validate phase. According to the "site lifecycle", validate isn't a phase, but my ant script gets run... twice! Not only that, it also compiles my source and runs tests (which takes FOREVER).
What gives, Maven? Your documentation doesn't match your runtime behavior.
Help?
Edit:
A plug-in, that explains it. Thanks, I'm using this reporting plugin:
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-report-plugin</artifactId>
<version>2.13</version>
</plugin>
</plugins>
</reporting>
I found this documentation on surefire report plug-in to be useful.
Some Maven plugins (like javadoc, for example) declare a 'forked lifecycle'. So, most likely, you have a plugin in your reporting configuration that demands a lifecycle that includes validate. If you are using an up-to-date copy of Maven (3.0.4), the -X option will include, amongst the thousands of lines of useless stuff, readable indications of this forking activity.

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