How to use maven to generate different artifactID with different scala version? - scala

I'm writing a library for scala 2.10 and scala 2.11.
When I install this library to maven local repository or publish to maven central. I want the artifactID of the library to have different suffixes, e.g. like:
org.apache.spark:spark-core_2.10:1.6.3 &
org.apache.spark:spark-core_2.11:1.6.3
This is easy in sbt, but my project is built in maven.
Is there a plugin that allows me to add the suffix to my artifactID easily according to different maven profile? So I can install and publish 2 different versions from a single project codebase.
Thanks a lot for your opinion!

I do this using Maven properties, e.g.
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<name>my-package</name>
<version>1.2.3</version>
<artifactId>${project.name}_${scala.compat.version}</artifactId>
...
</project>
You can set the scala.compat.version property either directly in the POM (if you only want one version), or in profiles (if you want to choose between multiple):
<properties>
<scala.compat.version>2.12</scala.compat.version>
</properties>
You can also specify it manually via the CLI, like mvn -Dscala.compat.version=2.12 package
Using the same property in your dependencies will ensure they match the chosen Scala version, e.g.
<dependency>
<groupId>org.typelevel</groupId>
<artifactId>cats-core_${scala.compat.version}</artifactId>
<version>2.1.1</version>
</dependency>
Note that this isn't ideal, since it generates the following Maven warning:
[WARNING] Some problems were encountered while building the effective model for org.example:my-package_2.12:jar:1.2.3
[WARNING] 'artifactId' contains an expression but should be a constant. # org.example:${project.name}_${scala.compat.version}:1.2.3, /private/tmp/nix-build-my-package_2.12-1.2.3.jar.drv-0/my-package-src/pom.xml, line 6, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.

Related

How to do a modular project architecture with Maven in Eclipse?

First of all im a little newbie in Maven+Eclipse world, so please excuse me if im not explaining myself good.
Im trying to implement Maven to existing Java old projects, the architecture im trying to achive is something like this (i put an image to explain myself a little better):
The project Utils have the most of the libs, that genericlly will be used for the other projects, and some classes that will be useful for the others (like date comparison method and mathematic method etc...), this project is working well with mvn install, generating the respective .war file.
The questions are:
The N Web Modules projects must have the project Utils as a
depedency and the most of dependencies too. I
don't know how to achive this in the pom.xml of N Web Modules
projects.
I don't know if it is posible in
Eclipse+Maven: Try to do some Parent Web Project that
implements the other projects and in one single mvn install the
parent project build and install the rest of the childs
(including Utils and N Web Modules).
I hope you can orientate and help me with this.
I think you are looking for Multi-Module projects
http://books.sonatype.com/mvnex-book/reference/multimodule.html
You can put various subprojects in one larger project and build them all at once. Furthermore, modules can depend on other modules (as long as this is not circular) and they are build in the correct order.
The project Utils have the most of the libs, that genericlly will be
used for the other projects, and some classes that will be useful for
the others (like date comparison method and mathematic method etc...),
this project is working well with mvn install, generating the
respective .war file.
One advise, you should extract classes used by other projects in a maven project with a JAR packaging and not leave them in a WAR packaging.
In Maven, generally, dependencies are provided as JAR.
It may also be provided as WAR by configuring the maven-war-plugin with some specific properties such as attachClasses but it looks like a trick and it also may create side effects.
Here are some information on how to do it.
But the documentation doesn't advise this way :
If you need to re-use this JAR/WAR in another project, the recommended
approach is to move the classes to a separate module that builds a
JAR, and then declare a dependency on that JAR from your webapp as
well as from any other projects that need it.
About your two questions.
The N Web Modules projects must have the project Utils as a dependency
and the most of dependencies too. I don't know how to achive this in
the pom.xml of N Web Modules projects.
Just include it as a dependency in the dependencies element of the consumer project :
<?xml version="1.0" encoding="UTF-8"?>
<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>mygroup</groupId>
<artifactId>project1-consumer</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
...
<dependencies>
<dependency>
<groupId>mygroup</groupId>
<artifactId>util</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
...
</dependencies>
</project>
I don't know if it is posible in Eclipse+Maven: Try to do some Parent
Web Project that implements the other projects and in one single mvn
install the parent project build and install the rest of the childs
(including Utils and N Web Modules).
What you are looking for is designing a multi-module project.
It relies on a aggregator pom that declares each module.
Note that this module has to be specified with a pom packaging as it doesn't produce a consumable artifact.
You could define something like that :
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>mygroup</groupId>
<artifactId>myaggregatorpom</artifactId>
<packaging>pom</packaging>
<version>1.0-SNAPSHOT</version>
<modules>
<module>util</module>
<module>project1-consumer</module>
<module>project2-consumer</module>
</modules>
</project>

Performing substitutions in Eclipse product configuration file with tycho

I have a Eclipse RCP product which I build with Tycho. After some smaller issues, this is working pretty fine and I have both CI and releases as wanted.
The product in question is provided both as an installable stand-alone RCP application and as an update site so the functionality can be installed in a vanilla Eclipse installation. This works fine as well.
The product have a main feature - which is used on the update site - and I would very much like the feature and the product to have the same version number. As it is today, this version number is mentioned is many places and I would really like to reduce this to just one. I currently have the version number in
the feature.xml of the main feature
the pom.xml of the same feature
the .product file for the product configuration file
the pom.xml of the project with the .product file
the categories.xml file of the update site
the about.mappings file
I have tried to use maven resource filters and that works for the POM files and about.mappings, but not for the rest. This is my current pom.xml for the main feature:
<?xml version="1.0" encoding="UTF-8"?>
<project ...>
<modelVersion>4.0.0</modelVersion>
<artifactId>...main.feature</artifactId>
<version>${product.version}-SNAPSHOT</version>
<packaging>eclipse-feature</packaging>
<parent>
<groupId>...</groupId>
<artifactId>...parent</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../...parent</relativePath>
</parent>
<build>
<!-- Substitutions: product.version -->
<resources>
<resource>
<directory>.</directory>
<includes>
<include>feature.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
When running this configuration, I get the following exception from Tycho (or an exception that looks very similar to it):
[ERROR] Internal error: java.lang.IllegalArgumentException -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.IllegalArgumentException
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:168)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
Caused by: java.lang.IllegalArgumentException
at org.eclipse.equinox.internal.p2.metadata.VersionParser.parse(VersionParser.java:93)
at org.eclipse.equinox.p2.metadata.Version.create(Version.java:79)
at org.eclipse.tycho.p2.impl.publisher.FeatureDependenciesAction.getVersion(FeatureDependenciesAction.java:126)
at org.eclipse.tycho.p2.impl.publisher.AbstractDependenciesAction.perform(AbstractDependenciesAction.java:79)
... 11 more
(I have cut some lines...)
Basically, the embedded maven process seems to not perform the resource filtering at all for this type of packaging. Or??
I have tried many different things, but I cannot get it to work. My best guess is that I have to configure the lifecycle, but how...
Can anybody help me with this?
this is a known bug:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=362252
You don't need to specify versions explicitly in the categories.xml. Just specify 0.0.0 as version, and Tycho will replace it by the actual version of the included feature.

Missing Maven dependencies in Eclipse multi-module project

I’m using STS 2.9.1 (build on Eclipse 3.7.2) with m2e plugin bundled with STS (v1.0.200.20111228-1245).
I have a problem regarding missing dependencies in Eclipse project that contains several modules, or maybe I don’t fully understand how it should work.
It’s a maven project.
In my Project > Properties > Java Build Path > Libraries I have “Maven Dependencies” library, but it's empty (and that’s the problem).
The main POM doesn’t have any dependencies, but it has several modules declared in it.
Adding a dependency to module’s POM doesn’t add it to the “Maven Dependencies” library (what was my expectation) and leads to Eclipse showing errors in source files.
Adding a dependency to the main POM adds it to the “MD” lib, but of course I don’t want to add all of my modules’ dependencies to the main POM just to have it in “MD” lib and adding every single dependency to the Build Path doesn’t seem right nor practical.
I’ve tried:
Project > Clean,
Maven > Update dependencies,
Maven > Update project configuration,
Unchecking the checkbox: Project > Properties > Maven > Resolve dependencies from Workspace projects.
None of the above seems to do the trick.
Example:
Simplified project structure:
simple.project
...
sample-module
...
pom.xml
pom.xml
simple.project/pom.xml:
<project ...>
<modelVersion>4.0.0</modelVersion>
<groupId>test</groupId>
<artifactId>simple.project</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>sample-module</module>
</modules>
<dependencies>
<dependency><!-- This dependency is present in "MD" lib. -->
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
</dependencies>
</project>
simple.project/sample-module/pom.xml:
<project ...>
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>simple.project</artifactId>
<groupId>test</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<groupId>test</groupId>
<artifactId>sample-module</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency><!-- I've expected this dependency also to appear in "MD" lib. -->
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
It is not supposed to work. A project only imports a dependency from another one if it depends on that project (using dependency) or if it inherits from it (using parent). The module element only represents an aggregation.
The question is from time ago, but I solved this creating a Maven Project and adding Maven Modules: right click on project and "New > Project... > Maven > Maven Module".
After that, no more errors were shown in code.
First thing that I see is that you're defining dependencies in a pom parent. There I would expect to see a <dependencyManagement> (see here the doc) structure. In this way the submodules will inherit properly those common dependencies.
Aside from that lets start for the most simple test. Try to compile your project from the maven utility in the command line. If it works then you have a problem in your Eclipse configuration, otherwise the problem is in the way you have defined your project.
If your project compiles properly from the command line, lets see what else can be happening.
The fact that the Maven Dependencies Library is empty means that the Eclipse Maven plugin is not resolving properly your poms. I had quite bad experiences with the embedded STS maven plugin. Try to downgrade it to the m2e 0.10 version. You only need to open the STS DashBoard / Find Updates / Install m2e 0.10
I hope some of these tips can help you.

Eclipse Maven runtime dependencies and profiles

Im trying to understand maven profiles and have run into the following issue.
This is my simplified example, I have two maven projects, project A and Project B.
project A has a compile time maven dependency on project B.
project B includes a runtime dependency (lets say to project C) when the maven profile "TEST" is active.
so the problem is the class path generated when I run project A. it doesn't have project C in it, even though the TEST profile is active for project A.
this is using eclipse Helios service release 1, Maven Integration for Eclipse plugin vrs 0.10.2.20100623-1649
any ideas?
I'm not sure that profiles are the best way to handle with TEST.
The use of profile to change dependecies will change the POM of the generated project.
If you install Project B with TEST activated, the runtime dependency will be added. (Whatever project A profile).
Optional dependencies are not added by transitivity. You need to add the dependency in project A.
I just tested this in Eclipse using m2eclipse 0.12.x. The second project pom.xml look like this:
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>org.test</groupId>
<artifactId>test2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<profiles>
<profile>
<id>TEST</id>
<dependencies>
<dependency>
<groupId>org.test</groupId>
<artifactId>test1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<scope>runtime</scope>
</dependency>
</dependencies>
</profile>
</profiles>
</project>
Then I set profile TEST as an active on Maven panel in the project properties dialog and made sure dependency resolution from Workspace is enabled there.
After that you can run any classes from test2 project's src/main/java and generated classpath looks like this:
C:\Dev\Java1.6\bin\javaw.exe -Dfile.encoding=Cp1252
-classpath C:\Dev\Workspace\test2\target\classes;C:\Dev\Workspace\test1\target\classes org.test2.Test2
Note, that dependencies with runtime scope only works for "Java Application" launch configuration type in Eclipse, but not for "JUnit" launch configuration, which uses different classpath resolver provided by m2eclipse's JDT integration.
It seems dependencies that are within profiles of dependent projects (transitive) dont give there runtime dependencies to the person who depends on them, This seems strange.
A work around was to add the profiles (containing the dependencies) to a parent then the children inherit the dependencies.
i.e. introduce a parent to A, I could have put them directly in A as YMomb kindly suggested. but its the inheritance aspect of this issue I needed to resolve as I have lots of projects As.

Maven and Eclipse code organization

I'm new to Maven, and after having read the docs on the maven site and Sonatype's online Maven book, I'm still not clear on how to best organize things.
I have two apps, A and B which share code from mylib. Different developers work on apps A and app B, they are released independently. Before we started with maven, in Eclipse, I'd have a workspace with apps A and B and mylib. The classpath for app A contained mylib. If I made a change in mylib, pressing run within Eclipse, contained my latest changes.
In Maven, I can create a parent pom.xml, which references app A and mylib. But this makes mylib a subdirectory of app A. How can I keep one instance of mylib and not link the building of apps A and B?
We use SVN for our SCM
Thanks
You have multiple options, however, potentially the simplest approach would be to separate out mylib into its own Maven project with its own life-cycle. The benefit of this approach is that you can support having multiple versions of mylib and your apps A and B can reference different versions of mylib as needed. If mylib and appA are open in Eclipse (and mylib references the version of mylib you have open), you can build the application in the same manner as you did prior to using Maven.
This approach does not mandate any dependencies between the directory structures of the applications, so you could go with something similar to the following:
/myapps/mylib
/myapps/appA
/myapps/appB
The downside to this approach is that maven will not automatically build both appA and mylib (or appB and mylib) as they are treated as separate applications. However, this may not be much of an issue if your applications are using pre-defined and built versions of mylib (that have been uploaded to your local maven repository using "mvn install").
Here is an example of the POMs for these projects:
mylib:
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.test</groupId>
<artifactId>myLib</artifactId>
<versioning>0.0.1</versioning>
<packaging>jar</packaging>
<name>mylib</name>
...
</project>
appA:
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.test</groupId>
<artifactId>appA</artifactId>
<packaging>jar</packaging>
<name>appA</name>
...
<dependencies>
<groupId>com.text</groupId>
<artifactId>mylib</artifactId</artifactId>
<version>0.0.1</version>
</dependencies>
...
</project>
appB:
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.test</groupId>
<artifactId>appB</artifactId>
<packaging>jar</packaging>
<name>appB</name>
...
<dependencies>
<groupId>com.text</groupId>
<artifactId>mylib</artifactId</artifactId>
<version>0.0.1</version>
</dependencies>
...
</project>
If you still want the convenience of a parent POM (one mvn package comment), then you could create a master pom in the /myapps folder similar to the following:
<project>
<groupId>com.test</groupId>
<version>0.0.1</version>
<artifactId>myapps</artifactId>
<packaging>pom</packaging>
<name>myapps</name>
<modules>
<module>shared</modules>
<module>appA</modules>
<module>appB</modules>
</modules>
</project>
This POM will automatically build myapp, appA and appB. If desired you could also create an appA and appB specific POM (pom-appA.xml). This is not the cleanest approach from a Maven perspective, but it will function. The only issue you would run into is if the version of mylib is not the version on which appA or appB is dependent. In that case your appA or appB code would be compiling against the version in your maven repository (if that version exists).
There are many other options you can use as well and I have seen plenty of discussions on Blogs and Wikis as to which is the best for various scenarios. However, it usually comes down to what works best for you and your organization. As long as it works and you are not going off building a custom, non-portable maven solution, then you are probably doing ok.
Hopefully this gives you some thoughts that you can use.