Difference between groupids net.sf.jasperreports and jasperreports - maven

I was using net.sf.jasperreports as the group for the version 3.6.0.
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>3.6.0</version>
</dependency>
For some reasons, I was asked to downgrade to the version 3.5.2.
<dependency>
<groupId>jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>3.5.2</version>
</dependency>
When I have taken a build it is observed that some of the jar files are missing like,
jcommon-1.0.15.jar
jdtcore-3.1.0.jar
Can anyone please explain me why this is happening. Are these jars are coming from net.sf.jasperreports? Please explain the difference between using groupids jasperreports and net.sf.jasperreports.

I'm pretty sure this is an inheritance from older maven conventions. The name of the groupId is merely an identifier and as such it only really has to be unique in the context it is being used. Se also http://www.mail-archive.com/users#maven.apache.org/msg34557.html
That means that as long as you don't use any dependencies outside of your own local repository (and stay offline), you could duplicate names of dependencies in maven central, for instance junit, primefaces or whatever.
So version 3.5.2 of jasperreports simply used artifactId as groupId (or vice versa), but later versions changed groupId to net.sf.jasperreports.
Dependencies between versions change, so it's pretty natural some artifacts "disappear" if you downgrade. If your project depends on these artifacts, you should explicitly define these as dependencies in your POM.

Related

Maven groovy-all change versions

I have dependency in pom with groovy-all
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>3.0.7</version>
<type>pom</type>
</dependency>
But if I check libs inside, I see 2.5.13 versions. How can I change all of this libs to 3.0.7? Of course I can add separately, but maybe is another option?
The versions are managed in the <dependencyManagement> section of the POM, either directly or by using a BOM (scope import).
If you want to update them, you need to look there.
You are importing Groovy 2.5.13 elsewhere likely as a transitive dependency and maven is deciding to use 2.5.13 instead of 3.0.7.
Look at the groovy 3.0.7 pom:
https://repo1.maven.org/maven2/org/codehaus/groovy/groovy-all/3.0.7/groovy-all-3.0.7.pom
It has no reference to 2.5.13.

Getting Maven to resolve missing dependencies with closest available matches

When I look at my local Maven cache (~/.m2/repository/) I see 10-20 versions of certain artifacts, some of which are being used for only a single specific build (project). I would like to get rid of this duplication (true, they are different versions, but I'd still think a depending project would be able to tolerate a micro or minor version difference) and to somehow ask Maven to resort to the closest available version during dependency resolution, if a specific artifact version is missing in the local repository.
For example, if I have versions 1.0.0, 1.1.2, 1.4.0 and 2.0.0 of a foo:bar artifact in my local cache, I would like Maven to:
use 1.1.2 for a build requiring 1.1.0
use 1.4.0 for a build requiring 1.4.10
use 2.0.0 for a build requiring 2.5.0
without having to manually change the pom of the specific build(s).
I am fairly aware of the risks associated with switching dependency versions without proper analysis, and I'm only asking for a mechanism to be utilized for non-critical builds (such as a tool/library that I just cloned off a VCS, and would like to run and try out), preferably activated only when a particular flag is provided.
Is there something out there, like a Maven extension or plugin (that can be applied on a system-wide scale, and activated on demand with a flag), that can help me achieve my goal?
P.S.: Since the definition of "closest" could be ambiguous (given the fact that Maven may not know which of 1.4.0 and 2.0.0 is closer to 1.5.0 depending on the actual release versions lying between them), it would even be sufficient if I can specify the version on the build command (e.g. mvn package -Dfoo:bar=1.4.0), still without making any manual pom changes. (While this may already be possible for versions that have been specified as <properties> entries, I would like a generic solution where even hard-coded versions in transitive dependencies could be overridden.)
P.P.S.: Please note tht the project(s) that would be built would not have been authored/composed by me, so I don't really have control/authority over their actual pom files. What I'm looking for is a way to override dependency versions in their pom files without doing any manual modifications at source level.
In order to change a transitive dependency, you need to exclude the transitive dependency in your direct dependency, then add a direct dependency in your pom.
For example, if you have a dependency on foo.jar (which depends on xyz.jar version 1.3) and on bar.jar (which depends on xyz.jar version 1.4), you can have these two sections in your pom:
<!-- Define the version(s) that you allow your dependencies to depend on. -->
<dependencyManagement>
<dependency>
<groupId>projectXyz</groupId>
<artifactId>xyz</artifactId>
<version>[1.0,2.0)</version>
</dependency>
<dependency>
<groupId>projectFoo</groupId>
<artifactId>foo</artifactId>
<version>1</version>
<exclusions>
<exclusion>
<groupId>projectXyz</groupId>
<artifactId>xyz</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>projectBar</groupId>
<artifactId>bar</artifactId>
<version>5</version>
<exclusions>
<exclusion>
<groupId>projectXyz</groupId>
<artifactId>xyz</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencyManagement>
...
<!-- Declare your dependencies but don't allow them to suck in their transitive dependencies. -->
<dependencies>
<dependency>
<groupId>projectXyz</groupId>
<artifactId>xyz</artifactId>
</dependency>
<dependency>
<groupId>projectFoo</groupId>
<artifactId>foo</artifactId>
</dependency>
<dependency>
<groupId>projectBar</groupId>
<artifactId>bar</artifactId>
</dependency>
</dependencies>
...
This will pick up the most recent version of xyz.jar that it can, and that will be the only version used. When foo and bar use xyz, they'll have the version that you've allowed into your project.
The best thing to do is to use a parent pom (or bom: bill of materials) with a well-defined and well-maintained dependencyManagement section. Stick with a single version of everything, just share that "everything" between all projects. You can override versions in projects if you need to.
If you'd rather define versions in each project, then version ranges will work. For the three examples you gave, you would use things like:
[1.1.0, 1.2)
[1.4.0, 1.5)
[2.0.0,)
(Open to correction here.. I haven't used version ranges in almost 10 years.)
Finally, to get it to use versions that are already available, rather than download the best ones, all you can do is to use a local artifact repository as your central maven repository, and turn off access to maven central and bintray.
Closest thing I found so far: https://github.com/jboss/maven-dependency-management-extension/blob/master/README.md
It can be dropped into ${MAVEN_HOME}/lib/ext and utilized for overriding versions of specific dependencies, e.g. mvn install -Dversion:junit:junit=4.10. While it doesn't offer the suggested "intelligent version derivation" approach, it's a good-enough solution.

Adding a dependency existing internally as a dependency

My project is a fairly large project consisting of many maven modules (but not microservices). I was trying to do Moving from spring to spring-bom on WAS but seems lot of clashes in versions. So for example one of my modules is using commons-collectionsversion 2.6.0 and my current project is using 3.2.2. I want the same jar to be used across. Since its more of a migration project I cannot do changes in container or repository changes at this time. I should only make sure that all the version are compatible with each other. My plan :
I want to include a dependency which is with in some other dependency
into the current pom as a dependency.
Also I want other jars in this pom (which exists as a dependency) to included the dependency
Is there anyway to do it?
I didn't completely understand your question, but the can help you to define a cross-module dependency version, as long as you place it in the parent-pom file.
<dependencyManagement>
<dependency>
<groupId>com.group</groupId>
<artifactId>project-1</artifactId>
<version>1.0.0</version>
</dependency>
</dependencyManagement>
and then define the dependency in the relevant module without providing it a version (it will be inherited from the parent-pom's <dependencyManagment> tag:
<dependencies>
<dependency>
<groupId>com.group</groupId>
<artifactId>project-1</artifactId>
</dependency>
</dependencies>

Force latest version for maven dependencies

I have the following dependency (only so far) pom.xml
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.6.2.RELEASE</version>
</dependency>
This dependency obviously depends on other "dependencies" via it's pom.xml... when maven finished downloading these dependencies I noticed that it didn't grab the latest version of the Spring stuff (4.0.6.RELEASE)... it grabbed a 3.2.x version.
How can I force maven to grab the latest version of the Spring stuff? Do I need to explicitly modify my pom.xml to include all the dependencies or is there some "magic" I can use for this?
Thanks.
Spring "Bill Of Materials"
Salvation may come from special "bill of materials" POMs supported by Maven and published by Spring. Quoting from Maven "Bill Of Materials" Dependency in their manual:
It is possible to accidentally mix different versions of Spring JARs when using Maven. For example, you may find that a third-party library, or another Spring project, pulls in a transitive dependency to an older release. If you forget to explicitly declare a direct dependency yourself, all sorts of unexpected issues can arise.
To overcome such problems Maven supports the concept of a "bill of materials" (BOM) dependency. You can import the spring-framework-bom in your dependencyManagement section to ensure that all spring dependencies (both direct and transitive) are at the same version.
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-framework-bom</artifactId>
<version>4.0.6.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Would this work for you?
Looking at the spring-data-jpa artifact pom file, we can see that it has a parent called spring-data-parent with current version 1.4.2.RELEASE. It's pom describes dependencies and their versions. Currently spring version is at 3.2.10.RELEASE
One way you can possibly accomplish what you want is to add explicit dependency on spring artifacts. But you would still have to define their versions.

Choosing dependency version in maven and maven plugin

I have a maven plugin which is using hsqldb 1.8.0.10. In my pom.xml from the plugin, it is declared like this:
<dependency>
<groupId>hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>1.8.0.10</version>
</dependency>
But if I run that plugin from another maven project, and that project has a newer version of hsqldb (for instance 1.9.0), how can I configure my plugin that he will use the newest version of hsqldb, without changing it's pom.xml?
And is it possible to do this the other way around as well? If my other maven project uses hsqldb 1.7.0 (for instance), that he will use the 1.8.0.10 version which is specified in the maven plugin itself?
I hope someone can answer my question.
Kind regards,
Walle
Your main question is possible, but it might not work properly if the plugin doesn't work with the newer code for any reason.
A plugin can have it's own personal dependencies section, and will use standard Maven dependency resolution, choosing the highest version requested. So, you can do
<plugin>
<groupId>some.group.id</groupId>
<artifactId>some.artifact.id</artifactId>
<version>someversion</version>
<dependencies>
<dependency>
<groupId>hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>1.9.0</version>
</dependency>
</dependencies>
</plugin>
I don't think going the other way around is possible, though.
use properties place holder for the version, say ${hsqldb.version} then declare in different project pom the version you want to put in it

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