I vote for #4. I've always used the convention of having stdlib stuff first, external stuff second, and same-project imports last. I guess increasing order of specificity?
Happy Holidays! Derek On Thu, Dec 22, 2022 at 7:52 AM Maxim Muzafarov <mmu...@apache.org> wrote: > > Hello everyone, have a great vacation and happy holidays to all! > > > I've completed a small research about how the classe's import order > rule are spread in the Apache projects. Some of the projects don't > have any restrictions over the imports even if they are using the > checkstyle configuration. The other ones may have only the consensus > over the imports, but they are not reflected in the checkstyle yet > (e.g. Kafka). The conclusion here can only be that there is a very > large variability in the classe's import order, so we have to agree on > the order on our own. > > You can find the projects, IDEs and frameworks and their corresponding > classe's import order below: > https://mmuzaf.github.io/blog/Java_Import_Orders.html > > > Most of the time during development in an IDE the classe's imports > remains collapsed, so from my point of view the following things > related to the classe's import comes into the first place to consider: > > - a PR review: newly imports must be clearly visible; > - try to minimize the total amount of affected files; > - the import order rule must be implemented in a simple way and well > supported by IDEs and its plugins; > > In addition to the last mentioned option, the checkstyle itself has > some limitations also. For instance, the ImportOrder has a limitation > by design to enforce an empty line between groups ("java", "javax"), > or CustomImportOrder may have only up to 4 custom groups separated by > a blank line. > > > > Based on all of the above I can propose the following classe's order. > All of them are tested on the latest changes from the trunk branch > (commit hash: b171b4ba294126e985d0ee629744516f19c8644e) > > > 1. Total 2 groups, 3072 files to change > > ``` > all other imports > [blank line] > static all other imports > ``` > > 2. Total 3 groups, 2345 files to change > > ``` > java.* > javax.* > [blank line] > all other imports > [blank line] > static all other imports > ``` > > 3. Total 5 groups, 2968 files to change > > ``` > org.apache.cassandra.* > [blank line] > java.* > [blank line] > javax.* > [blank line] > all other imports > [blank line] > static all other imports > ``` > > 4. Total 5 groups, 1792 files to change > > ``` > java.* > javax.* > [blank line] > com.* > net.* > org.* > [blank line] > org.apache.cassandra.* > [blank line] > all other imports > [blank line] > static all other imports > ``` > > 5. Total 2 groups, 3114 files to change > > ``` > java.* > javax.* > org.apache.cassandra.* > all other imports > [blank line] > static all other imports > ``` > > > Of course, any suggestions are really appreciated. > Please, share your thoughts. > > On Thu, 15 Dec 2022 at 17:48, Mick Semb Wever <m...@apache.org> wrote: > >> > >> Another angle I forgot to mention is that this is quite a big patch and > >> there are quite big pieces of work coming, being it CEP-15, for example. > >> So I am trying to figure out if we are ok to just merge this work first > >> and devs doing CEP-15 will need to rework their imports or we merge this > >> after them so we will fix their stuff. I do not know what is more > >> preferable. > > > > > > > > Thank you for bringing this point up Stefan. > > > > I would be actively reaching out to all those engaged with current CEPs, > > asking them the rebase impact this would cause and if they are ok with it. > > The CEPs are our priority, and we have a significant amount of them in > > progress compared to anything we've had for many years. > > > > > > -- +---------------------------------------------------------------+ | Derek Chen-Becker | | GPG Key available at https://keybase.io/dchenbecker and | | https://pgp.mit.edu/pks/lookup?search=derek%40chen-becker.org | | Fngrprnt: EB8A 6480 F0A3 C8EB C1E7 7F42 AFC5 AFEE 96E4 6ACC | +---------------------------------------------------------------+
