Develop Reference

Versions Maven Plugin rules that are inheritable

When running mvn versions:display-dependency-updates for the Version Maven Plugin I see lots of things like this:
[INFO] org.slf4j:slf4j-api ........................... 1.7.36 -> 2.0.0-alpha7
But just because I'm not using the alpha version of a later version doesn't mean I'm not using the latest available release version. Another Stack Overflow answer indicated that I can set up a rules.xml file to ignore versions like *.-alpha*, putting something like this in my POM:
<configuration>
<rulesUri>file:///${project.basedir}/rules.xml</rulesUri>
</configuration>
My question: is this rules.xml file inheritable? If I put it in a separate project in a parent POM of <packaging>pom</packaging>, published to Maven Central, will the child POMs pick it up? Or will the child projects look for a rules.xml file in the child project directory?
I want to configure the versions-maven-plugin in the parent POM (as I do already) and run mvn versions:display-dependency-updates on any child POM or descendant POM. How can I set up the ignore rules in the parent POM so that these version ignore rules will be picked up when I check for dependency updates in a child POM? (Is there no way to include the rule within the POM itself?)

Or will the child projects look for a rules.xml file in the child project directory?
Yes, if you define the rules.xml file via ${project.basedir} it will resolve to the current local base directory of the child project. I've verified this with a simple parent-child pom setup. So that will not work, unless you duplicate the rules file in every project.
If you wish to include the plugin configuration and ruleset in the parent pom without duplicating the rules file, you have two options:
If you have your ruleset xml file hosted at, for example, http://www.mycompany.com/maven-version-rules.xml then the following configuration in your corporate pom would ensure that all projects use this rule set.
<configuration>
<rulesUri>http://www.mycompany.com/maven-version-rules.xml</rulesUri>
</configuration>
or
You can provide your ruleset xml file also within a jar, if you want to distribute your ruleset xml as Maven artifact. Therefore you have to declare the containing jar as direct dependency of the versions-maven-plugin and to use classpath as protocol.
<configuration>
<rulesUri>classpath:///package/foo/bar/rules.xml</rulesUri>
</configuration>
<dependencies>
<dependency>
<groupId>com.mycompany</groupId>
<artifactId>version-rules</artifactId>
<version>1.0</version>
</dependency>
</dependencies>
Source:
https://www.mojohaus.org/versions-maven-plugin/version-rules.html
The configuration in the pom only has rudimentary includes and excludes filters. Those will allow you to exclude any dependency as a whole, but not specific update versions. As far as i can tell from the available documentation there is no way to define version rules in any other way.
See
https://www.mojohaus.org/versions-maven-plugin/examples/advancing-dependency-versions.html
Update 09-2022
In the github ticket we found in the comments we can see the following update:
It looks like a feature like this has recently been implemented by #369. Please see #318 where it's possible to provide inclusion and exclusion filters for determining which dependency patterns will be considered. Thanks to that, you can rule out patterns such as .*-beta. or .*_ALPHA, albeit not using regexp, but simple asterisk wildcards.
This will land in today's release (2.12.0).
This will add the following features:
Version 2.12.0 will introduce new arguments: dependencyIncluded, dependencyExcludes, dependencyManagementIncludes, dependencyManagementExcludes.
With the following example configuration in pom.xml given:
<profile>
<id>display-dependency-updates</id>
<build>
<plugins>
<plugin>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>display-dependency-updates</goal>
</goals>
<configuration>
<dependencyIncludes>org.apache.maven.*:doxia*</dependencyIncludes>
<dependencyManagementIncludes>com.puppy*:*</dependencyManagementIncludes>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
This will also be implemented for filtering plugin and pluginManagement, but that will probably be added in a later release:
So, I've just added the missing plugin- and plugin management filtering which works likewise. I really doubt it will land into today's release though.

Pasting my answer here from Github, because I think it might benefit others.
Provided you have a directory called rules-test in your project containing the rules template file:
<ruleset comparisonMethod="maven"
xmlns="http://mojo.codehaus.org/versions-maven-plugin/rule/2.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://mojo.codehaus.org/versions-maven-plugin/rule/2.0.0
https://www.mojohaus.org/versions-maven-plugin/xsd/rule-2.0.0.xsd">
<ignoreVersions>
<ignoreVersion type="regex">${ignoredVersions}</ignoreVersion>
</ignoreVersions>
</ruleset>
Then, in your main project, create the following profile:
<profile>
<id>rules-test</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>3.3.0</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<resources>
<resource>
<directory>rules-test</directory>
<filtering>true</filtering>
</resource>
</resources>
<outputDirectory>${project.basedir}</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>versions-maven-plugin</artifactId>
<version>2.12.0</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>display-dependency-updates</goal>
</goals>
<configuration>
<rulesUri>file://${project.basedir}/compiled-rules.xml</rulesUri>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
If you then execute the following Maven target:
mvn -P rules-test "-DignoredVersions=.*-(M\d*|.*-SNAPSHOT)" clean validate
then you will get a dependencies report using the filter in the -DignoredVersions argument (filtering out both *-M* and *-SNAPSHOT).
And if you put your ignoredVerions property in your project instead of passing it as a -D argument, then it will be inheritable!

Maven-compiler-plugin throws wanted compile errors but deny the compile progress

A few days ago i started with Maven. I have to put only a few of my dependencies in my generated jar file. This is needed because my code is only a plugin (Minecraft Plugin) executed by an api (Minecraft Server Software Spigot). Now the Problem is, that my Plugin depends on an other api (json-simple-1.1).
The last days i tried to edit the maven shade plugin to get the wished result. I failed, and now i did it in this way:
maven include the json-simple-1.1 api, i needing for my plugin
eclipse include the spigot api (Minecraft server software), which will executing my plugin
pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>de.falco.essentialsXXX</groupId>
<artifactId>EssentialsXXX-bungeecord</artifactId>
<version>0.0.1-SNAPSHOT</version>
<description>Basic class for every Plugin
</description>
<build>
<sourceDirectory>src</sourceDirectory>
<!-- COMPILE -->
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<!-- BUILD -->
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-json</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>com.googlecode.json-simple</groupId>
<artifactId>json-simple</artifactId>
<version>1.1.1</version>
</dependency>
</dependencies>
</project>
When i now execute 'mvn clean install' (in the right directory) i get many many errors. That make completely sense. Maven can not find types or classes and everything else comeing from the spigot-api.
My Problem is, that this isnt a real error because when the spigot-api execute my plugin i have the classes and types i need. Maven dont know that and dont compile my Programm :(
At this point a have no idea what to do. I read so many articles but i couldnt find a solution. Every article say ohhh an error here try to use tags and the right api values. That isnt what i need.
I need something like a "bypass" attribute for the compiler so the compiler know "yes this is an error but the coder knows what he does"

If you need something for compilation, it needs to be a Maven dependency.
So take that artifact, install it in your local repository and add it as dependency.
Then your compilation process will probably work.
Note that using a dependency does not mean that you have to include the dependency into the resulting jar.

Installing local jar file to maven repo without using command line

I have a maven project that I just added some features to and in order to do so I had to add a local jar dependency. I have added this jar file to the lib folder of the project on Github, and I want to make it so anyone who downloads the project off Github can install that jar to their m2 directory without having to use the maven install:install-file command through command line. The POM file has the dependency already but I need a way to programmatically install the jar file when building the snapshot with mvn install.
Thoughts?

Option 0:
Deploy the jar file to a public or comany-wide maven repository. If the project producing this jar is also a git(hub) project, consider using a service like Jitpack
Option 1:
Ugly, but could work.
<dependency>
<groupId>com.bar</groupId>
<artifactId>foo</artifactId>
<version>42</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/foo-42.jar</systemPath>
</dependency>
Option 2:
Even more ugly, but could work even better.
<build>
<plugins>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<executions>
<execution>
<id>install-foo</id>
<goals>
<goal>install-file</goal>
</goals>
<phase>generate-sources</phase>
<configuration>
<groupId>com.bar</groupId>
<artifactId>foo</artifactId>
<version>42</version>
<file>${project.basedir}/lib/foo-42.jar</file>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>

how to deploy multiple wars using the tomcat plugin in maven

From the forums that I followed I tried some ways to find a way to deploy mutliple wars using tomcat plugin in maven but I could not succeed.
I created a third project and used three projects in order to deploy them but I have not done it. Could you please tell me way to do it ?
Best Regards
Alper Kopuz
Here is the pom.xml that I used :
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>
tr.com.provus.pays
</groupId>
<artifactId>PAYSGroupProject</artifactId>
<version>1.0</version>
<packaging>pom</packaging>
<modules>
<module>../PAYSWeb</module>
<module>../PAYSDashboard</module>
<module>../PAYSStaticWeb</module>
</modules>
<name>PAYSGroupProject</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<executions>
<execution>
<id>deploy</id>
<phase>pre-integration-test</phase>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
</configuration>
</plugin>
</plugins>
</build>
</project>

I guess you cannot use the tomcat plugin on a pom type project, try instead to configure the plugin into one of the war projects and include the others as webapp dependencies with something like that :
<configuration>
<webapps>
<webapp>
<contextPath>/PAYSWeb</contextPath>
<groupId>tr.com.provus.pays</groupId>
<artifactId>PAYSWeb</artifactId>
<version>${project.version}</version>
<type>war</type>
<asWebapp>true</asWebapp>
</webapp>
<webapp>...</webapp>
</webapps>
</configuration>
Look also at this post (but unanswered)

Each webapp will need a different context root which is supplied to the tomcat7 maven plugin with the "path" value.
You will deploy each web app from its own POM independently. But since you have a pom type project that causes the others to build, you should be able to redeploy all three at once.
Note that there are two ways to deploy using this plugin:
You can deploy without the war. It just compiles the java files and deploys them directly to tomcat.
You can deploy the war. Maven will have to build the war and then it gets deployed to Tomcat. This is more like a production deployment and helps you verify the war will deploy correctly.
So. Move your plugin XML to each of the three "modules" pom files. They will have type 'war'. Then add this under configuration:
<path>paysWeb</path>
under the <configuration> tag for the first 'module'. Of course, you use the different names for the <path> for each of the 'module's.
There is more info here: http://tomcat.apache.org/maven-plugin-2.0/tomcat7-maven-plugin/usage.html

Get sources of a snapshot dependency on Eclipse

Something bother me a lot...
On a big project with many dependencies, some of them are set as SNAPSHOT in Maven2.
The matter is that it seems i can't get the sources through Eclipse without loading the project or fixing the dependency to the last release.
For debugging, it's really annoying me...
EDIT
This is what i get in eclipse maven console:
26/08/10 11:31:46 CEST: Downloading http://repo-maven/archiva/repository/snapshots/com/blabla/1.1-SNAPSHOT/blabla-1.1-20100824.213711-80-javadoc.jar
26/08/10 11:31:47 CEST: Could not download sources for com.blabla:blabla:1.1-20100824.213711-80
On archiva i can see the deployed stuff i want to retrieve in eclipse...
Repository snapshots
Group ID com.blabla
Artifact ID blabla
Version 1.1-20100824.213711-80
Packaging jar
Parent com.blabla bla 1.1-SNAPSHOT (View)
Other Versions 1.1-20100824.213535-79
I can download sources of this artifact with my browser but not within Eclipse... Any idea?

The matter is that it seems I can't get the sources through Eclipse without loading the project or fixing the dependency to the last release. For debugging, it's really annoying me...
Well, these modules are probably not publishing source JARs as part of the "regular" build process (i.e. outside the release). If these modules are under your control (which is my understanding), configuring the Maven Source Plugin to produce source JARs for them and deploying them in your corporate repo should solve the problem. From the Usage page:
Installing the sources along with your artifact
There are two ways to do this. You can
either bind this plugin to a phase or
you can add it to a profile. The goals
source:jar-no-fork and
source:test-jar-no-fork are preferred
for binding the goal to the build
lifecycle.
Installing the sources using a phase binding
Here is how you would configure the
plugin in your pom.xml to run
automatically during the verify phase:
<project>
...
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>2.1.2</version>
<executions>
<execution>
<id>attach-sources</id>
<phase>verify</phase>
<goals>
<goal>jar-no-fork</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
...
</project>
We are using the verify phase here
because it is the phase that comes
before the install phase, thus making
sure that the sources jar has been
created before the install takes
place.
Installing the sources using a profile
If you want to install a jar of your
sources along with your artifact
during the release process, you can
add this to your pom.xml file:
<project>
...
<profiles>
<profile>
<id>release</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>2.1.2</version>
<executions>
<execution>
<id>attach-sources</id>
<goals>
<goal>jar-no-fork</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
...
</project>
Using a profile would probably be a good idea so that building source JARs will only be done by the build running at the CI server level but not on developer machines.