Hi Mina folks,
as I was attending ApacheCon at Austin, I have had many interesting
discussions with some Maven peeps. It's really good to have those guys -
Martin Van Den Bemt, Jason Van Zyll, all theose 'van' something :) - around.
They showed me a very cool feature of Maven called Dependency Management.
The idea is to a void using jars version into leaf projects, but instead
gather all the used number into the top level project. Ok, let's have a
sample :
we have Mina, and we have many sub-projects like Mina-core,
Mina-filter-compression, etc, all of those guys having a pom.xml depending
on the top-level pom.xml. We are using nlog4j-1.2.25 in almost all the jars,
commons-xxxx in many of those sub-projects, etc. So what we should do is to
declare those dependencies in all the pom.xml, but remove the version number
in all of them, and add a list of dependencies in the top level project with
the vesion, like that :
<dependencyManagement>
<dependencies>
<dependency>
<groupId>antlr</groupId>
<artifactId>antlr</artifactId>
<version>2.7.2</version>
</dependency>
<dependency>
<groupId>backport-util-concurrent</groupId>
<artifactId>backport-util-concurrent</artifactId>
<version>2.1</version>
</dependency>
...
</dependencyManagmenent>
and in, let's say, mina-filter-compression pom.xml, we will have that :
...
<dependencies>
<dependency>
<groupId>org.apache.mina</groupId>
<artifactId>mina-core</artifactId>
<version>${pom.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<!--version>1.0</version--> !!!! Note that I commented
the version here
<scope>provided</scope>
</dependency>
What is this good for? It helps us saving time when we have to bump up a new
version of a jar. For instance, nlog4j is used in almsot all sub-poject, so
when we go to 1.2.19 to 1.2.25, it takes a hell of time changing 40
subprojects pom.xml. And it's error prone. Instead of doing that, with
dependency managment, we just have to change one single file.
So, question : what do you think about adopting this technic in Mina ? (the
top level pom.xml will be the MINA ones). It can also be used to bump up
MINA version when a new release is created.
Just tell me, I can do the modification.
Emmanuel Lécharny
--
Cordialement,
Emmanuel Lécharny
