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Distribute plugin resource files to host project

I have a maven plugin that exposes a Mojo, with a goal that runs at the compile stage. The project was generated using mvn archetype:generate, and the POM contains all the standard stuff that comes with running that, very little deviation. The project includes a couple of resource files, e.g. filea.txt and fileb.txt, that are packaged up as part of the jar.
When the plugin is used in a project, I'd like the files that are included in the jar to be extracted and copied to the target\test-classes directory of the host project. I'm trying to use the plugin jar to both distribute some files + expose some functionality that can then use those files.
Is this a valid approach, and if so, are there settings I can add to the plugin POM to indicate that content from the plugin should be extracted and copied? I want to centralise this logic in the plugin, rather than having to do in the plugin host.
I feel like it's something with maven-dependency-plugin or maven-resources-plugin or build-helper-maven-plugin:attach-artifact, have tried a couple of different approaches but think I'm missing something obvious:
e.g. something like this in plugin POM?
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<outputDirectory>${basedir}/target/test-classes</outputDirectory>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>filea.txt</include>
<include>fileb.txt</include>
</includes>
</resource>
</resources>
</configuration>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.6.0</version>
</plugin>
// etc etc
Google fu has let me down, keep ending up on maven resources page. Can post directory structure / more information if needed.
Cheers

First I would suggest to put resources which needs to be distributed into src/main/resources which looks like you have done ...but remove the configuration for the maven-resources-plugin and let maven do it's work. This is automatically copied into target/classes/ which in result is packaged into the resulting jar later.
If your plugin needs to get those files those can accessed as a usual resource via this.getClass().getResourcesAsStream("/...") and reading and writing them into a new location preferable into target/...

Maven compile UTF-8 & properties files

I am using maven to compile my project using this configuration:
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<encoding>UTF-8</encoding>
<source>${java.version}</source>
<target>${java.version}</target>
<showDeprecation>true</showDeprecation>
<showWarnings>true</showWarnings>
</configuration>
</plugin>
</plugins>
The project should be in UTF-8, but by convention .properties files should be latin1 (ISO 8859-1) and Eclipse treats them that way (I know I can change how Eclipse behaves, but that's not the point). I use .properties files for internationalization.
The problem is that, using Eclipse to deploy to Tomcat, I can see my special chars well, but when compiling through maven (for instance, through Jenkins), I get all messed characters, like somehow Maven is translating all my .properties into UTF-8, thus screwing all my i18n messages.
What is the proper way to solve this? It feels like this should be a very common problem but I haven't found a valid solution online.

Just make a supplemental entry for resources directory which contains the ISO-LATIN1 files and turn off filtering explicitly. Than those files should be kept as they are...
BTW: You should use the encoding property like:
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
which is recognized by a large number of plugins for example maven-compiler-plugin, maven-resources-plugin etc.

Maven War Plugin Websphere

I am trying to get a Rational Application Developer project to run on a websphere server. I am trying to get the maven-war-plugin to work. However, when trying to start the server, websphere can not find the UI Files. I have my plugin here:
<build>
<outputDirectory>${project.basedir}\WebContent\WEB-INF\classes</outputDirectory>
<finalName>${project.name}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.6</version>
<configuration>
<webXml>/WebContent/WEB-INF/web.xml</webXml>
<webappDirectory>WebContent</webappDirectory>
<source>/codeCoverageUI2/src/</source>
<encoding>utf-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
I feel the issue is with my webappDirectory but I do not know what else to put it to, besides the location of all my UI files.
Anyone have some insight?

I am assuming you are using WebSphere Classic V8 or earlier?
What we recommend because when developing a project in RAD/WDT, WAS Classic requires building the project in a "Single Root" structure. Add the following to your pom:
<build>
<outputDirectory>${project.basedir}\WebContent\WEB-INF\classes</outputDirectory>
<finalName>${project.name}</finalName>
...
This will build your source within the Web content folder. (Make sure you do a Project -> "Maven" -> "Update Project...") then rebuild...

Maven: how to do runable jar (uberjar) with included external libraries

Until now i made runnable jars with Ant and there were no problems with it.
However i now try to mavenize my project and i realy can't figured out how to do runable jar with this tool.
I've read tons of tutorials (also here, on Stackoverflow), helps, advices and... nothing. In my case all of them don't work which probably means i don't understand some basics.
I have such simple project:
This is app, witch use mysql-connector-java-5.1.24-bin.jar (placed in 'lib' dir) to connect to MySQL database.
I want to include this jar into final jar (DBPreformatter.jar).
I used assembly and shaded plugins in many configurations, but they NEVER added this jar into DBPreformatter.jar.
This is my pom.xml:
<modelVersion>4.0.0</modelVersion>
<groupId>com.icd4you</groupId>
<artifactId>DBPreformatter</artifactId>
<version>1.0.0</version>
<name>DBPreformatter</name>
<description>DB processing and cleaning tool</description>
<packaging>jar</packaging>
<dependencies>
<dependency>
<groupId>mysql-connector-java-5.1.24-bin</groupId>
<artifactId>mysql-connector-java-5.1.24-bin</artifactId>
<version>5.1.24</version>
<scope>system</scope>
<systemPath>${basedir}/lib/mysql-connector-java-5.1.24-bin.jar</systemPath>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<!-- WHAT SHOULD I USE HERE? -->
</plugins>
</build>
How to solve this problem?

There is a maven plugin Apache Maven Shade Plugin that will build an uber jar for you

Add the Maven Assembly plugin with the descriptor jar-with-dependencies:
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.pany.your.MainClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
Note that this doesn't add the JAR; instead it unpacks all JARs which are listed as dependencies and adds their content to the resulting JAR (so you'll see all the class files from the MySQL JAR in the result instead of the MySQL JAR itself).
EDIT There is a caveat, though: Maven ignores JARs with scope=system for many operations. See also: How to include external jars in maven jar build process?
If Maven doesn't add the JAR to the output, then you must install all JARs with this scope into your local maven repo ($HOME/.m2/repository) using the mvn install:file-install command. See http://maven.apache.org/plugins/maven-install-plugin/usage.html how to do that.
Note: Installing libraries in your local repo is the preferred way; you should really consider it. For one, the scope=system will no longer confuse you (since many plugins handle them in a special way). Plus you need to do this only once. Afterwards, you can use this library in many Maven projects.
Before installing, you should check http://search.maven.org/ to see if the dependency isn't already known to Maven.
MySQL is: http://search.maven.org/#artifactdetails%7Cmysql%7Cmysql-connector-java%7C5.1.32%7Cjar

Compiling only selected files in Maven

I want to compile only selected files or directories (including subdirectories) within source directory. I was pretty sure I can do this using <includes> of maven-compiler-plugin's configuration, but it seems to not work as I expect since it still compiles all classes into target/classes. What is really strange, Maven output suggest that the setting actually does its work, because with:
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<includes>
<include>com/example/dao/bean/*.java</include>
</includes>
</configuration>
</plugin>
I have:
[INFO] Compiling 1 source file to c:\Projects\test\target\classes
but with no compiler's configuration I have:
[INFO] Compiling 14 source file to c:\Projects\test\target\classes
In both cases however, all 14 classes are compiled into target/classes as I mentioned. Can you explain that or suggest another solution to compile only selected files?

Simple app with 3 classes.
com/company/Obj1.java
com/company/Obj2.java
com/company/inner/Obj3.java
build in pom.xml
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.0.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<includes>
<include>com/company/inner/*.java</include>
</includes>
</configuration>
</plugin>
</plugins>
</build>
result: 1 class is compiled.
And any combination of includes is working well
or you mean something else?

I have faced a similar situation. We needed to hot swap only modified files to our remote docker container in order to improve changes-deploy time. This is how we solved it.
Add includes option in build plugin with command line argument.
Note since we wanted to add multiple files, so we have used includes and not include
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<compilerVersion>1.8</compilerVersion>
<source>1.8</source>
<target>1.8</target>
<includes>${changed.classes}</includes>
</configuration>
</plugin>
Now run compile phase with argument, example:
mvn compile -Dchanged.classes=com/demo/ClassA.java,com/demo/ClassB.java,com/demo2/*

maven-compiler-plugin using Ant-like inclusion/exclusion notation.
You can see examples in Ant documentation Ant FileSet Type
If you are want include only files from one directory, you need write it like you did:
<include>com/example/dao/bean/*.java</include>
To include also subdirectories from path, it will be:
<include>com/example/dao/bean/**/*.java</include>

I had no difficulty including or excluding files for compilation with maven compiler plugin 2.5.1. Here is the dummy project I used for the purpose. Perhaps the include pattern that you use is different.