Maven卡在旧版本的系统依赖项上

Question

My Maven project has a dependency on a non-Maven library, which is coded as a system dependency:

<dependency>
  <groupId>com.example</groupId>
  <artifactId>foo</artifactId>
  <version>${foo.version}</version>
  <scope>system</scope>
  <systemPath>${foo.jar}</systemPath>
</dependency>

where the location of the library can be controlled via local properties:

<properties>
  <foo.version>2.1.1</foo.version>
  <foo.basedir>/usr/local</foo.basedir>
  <foo.libdir>${foo.basedir}/lib</foo.libdir>
  <foo.jar>${foo.basedir}/java/foo-${foo.version}.jar</foo.jar>
</properties>

Recently, the library switched from version 2.1.1 to version 2.2.0, so I changed the foo.version property, but Maven seems to be stuck on the old version:

...
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to resolve artifact.

Missing:
----------
1) com.example:foo:jar:2.1.1
...

I have run mvn dependency:purge-local-repository (many times, actually). The string 2.1.1 does not appear anywhere in my POM, profiles.xml , or settings.xml . Still, every time I try to build my project, Maven fails with the above error.

What's going on here? Where is Maven storing the dependency version information and how can I update it?

Answer 1

I think the ${foo.version} might be getting resolved as a filter property. Can you check the properties file under src/main/filters .

Not sure if this is indeed the problem but just give it a try and update back.

The other reason that I could think of is - there might be a transitive dependency on com.example:foo:jar:2.1.1 . That is some other dependency which needs 2.1.1 version of this artifact. You can find which artifact is bringing this transitively by doing mvn dependency:tree

Answer 2

Dependency version conflict is a very common problem and most of the time when we start building our application, we never focus or generally we forgot on that aspect until and unless our application starts behaving in an unexpected way or getting started some exception.

For readers and visitors of SO who are interested in knowing the reason why dependency conflicts arises and how we can avoid them in our application , I found a source here explained in a precise way ,so i thought of adding my 2 bits to it .

http://techidiocy.com/maven-dependency-version-conflict-problem-and-resolution/

Cheers

Answer 3

You know what. Seeing the workaround that @Chris Conway found, I think that this might have been "solved" by simply running mvn clean .

And even if it would not have helped here, it is always worth trying mvn clean when something strange happens.