For static project files in Gradle, add the "idea" or "eclipse" plugins (if using spring prop-deps plugin then use their version of these). Then there are tasks to generate and merge with project files:
apply plugin: "idea"
apply plugin: "eclipse"
And you'll end up with files. Read the pages above for more details on updating just parts of the projects and how they merge with pre-existing projects.
If you have old project files from dynamically created projects (from opening build.gradle or pom.xml), you may want to clear them first, not sure how they would collide.
For Maven, there are idea and eclipse plugins as well, but I am not sure if Maven has the same potential slowdown as Gradle has (Gradle was mentioned in the YouTrack issue above, not Maven). And I haven't used Maven in 2 years so can't help much more. Other than to say "move to Gradle, why are you suffering?!?"