Bring in support for mapstruct

[gayanper]

The IDE support at https://github.com/mapstruct/mapstruct-eclipse/tree/master would be nice if we can bring in the jdtls as we have done with Lombok.

[gayanper]

@jdneo @snjeza @testforstephen @rgrunber WDYT?

[gayanper]

I just looked into original eclipse plugin and its fairly simple plugin, but it depends on JDT UI components for quickfixes and completions.

Since the plugin is not updated during last 7 years, We have few options

• Check with the author if they would like to receive some updates into the plugin so that we can make the mapstruct plugin logic reusable in jdt.ls by decoupling them from JDT UI.

• Implement the mapstruct support from scratch in jdt.ls

I would prefer the first option, either on the original repo or a fork under the eclipse, microsoft or redhat org.

[jdneo]

Check with the author if they would like to receive some updates into the plugin so that we can make the mapstruct plugin logic reusable in jdt.ls by decoupling them from JDT UI.

Will it be a plugin of JDT.LS( like https://github.com/microsoft/vscode-lombok), or directly enabled in JDT.LS?

[gayanper]

Check with the author if they would like to receive some updates into the plugin so that we can make the mapstruct plugin logic reusable in jdt.ls by decoupling them from JDT UI.

Will it be a plugin of JDT.LS( like https://github.com/microsoft/vscode-lombok), or directly enabled in JDT.LS?

I'm thinking adding it as a plugin of JDT.LS for providing content assist and quick fixes. But i would like to start with content assist first.

Ofcourse we need to think about annotation processing as well. That could be done as we have supported lombok may be. WDYT ?

[jdneo]

I'm thinking adding it as a plugin of JDT.LS

Yes, it looks good to me.

[gayanper]

I think we need this feature support #2653 before we can continue on this.