Question

Could you give me a detail explanation about the difference between jar and jar-no-fork goal?

I see it from official site, but I can not get a clear idea for this.

Answer 1

My interpretation: the jar goal is meant to be run from the command line (mvn source:jar), the jar-no-fork is meant to be bound to the lifecycle.

If you look at the docs for the jar goal the key phrase is “Invokes the execution of the lifecycle phase generate-sources prior to executing itself.” If you configure your POM to run the source:jar goal as part of the lifecycle, Maven will re-run all of the goals bound to generate-sources and its predecessors. If you have many plugin goals bound to the validate or initialize phases all of those will run twice, lengthening the time of your build.

In contrast, jar-no-fork is what you attach to the build lifecycle because it expects to be bound to a phase somewhere after generate-sources and will not run the bound goals again.

I have verified this behavior by running Maven 3 with -X and reviewing the plugin executions that run.