support maven-wrapper like gradle-wrapper

[BigMichi1]

What would you like Renovate to be able to do?
A lot of new projects which are using maven relay on the maven-wrapper (https://github.com/takari/maven-wrapper) so maven behaves in the same way like gradle. you don't need to install a maven locally, it's just calling ./mvnw and it will download the defined version in maven-wrapper.properties. So it would be really nice if there is also support for updating maven-wrapper. Maven wrapper consists of 4 files, 2 of them are stored in .mvn/wrapper/ directory the other two are the executables in the project root directory

• ./mvn/wrapper/maven-wrapper.jar - downloading logic
• ./mvn/wrapper/maven-wrapper.properties - contains the url and version of maven which should be used for the project
• ./mvnw - linux executable
• ./mvnw.cmd - windows executable

Describe the solution you'd like
solution should consist of two parts:

• detection if new maven is available and update the version for maven just in the properties file
• detection if new wrapper is available und update possibly all 4 files (exectables, properties file and download logic)

Describe alternatives you've considered
first thing can be achieved by manually changing the maven version number in maven-wrapper.properties
second thing can be also achieved by manually executing mvn -N io.takari:maven:0.7.6:wrapper -Dmaven=3.3.3 where the version of maven is pinned to the currently used on and a new version of the wrapper is specified

Additional context
maybe the logic from the gradle-wrapper check can be reused and extended to cover both situations for maven (gradle uses only one version for the wrapper and the distribution)

[HonkingGoose]

@rarkins @viceice This issue should probably be reviewed, as there has been no real change to this issue since it was opened. We only moved some labels around... 😉

[viceice]

I think this is ready to be implemented but would need a community contribution 🙃

[viceice]

I think the gradle-wrapper manager can be used as base for this

[rarkins]

First step is probably to add a maven-version datasource modeled after lib/datasource/gradle-version

[breun]

Maven Wrapper has migrated from Takari to an official Maven project: https://maven.apache.org/wrapper/

[benkelaar]

As mentioned in this discussion @trystian1 and I are working on this feature.

[renovate-release]

🎉 This issue has been resolved in version 34.111.0 🎉

The release is available on:

• GitHub release
• 34.111.0

Your semantic-release bot 📦🚀