问题
I am using play framework with java to develop a web application. I have wanted to read a file at the run time and the file has been included in a folder in the project. But at the production environment the folder is not available. Is there a way to make the folder available at the run time? And specially, is there a default method in play to handle such a scenario?
I went through the question "How to read a file in Play Framework 2.2.1?1" But there is no mention about the problem in the production environment.
回答1:
You can choose a location you prefer other than in dedicated folders for some specific tasks. For an example you can create /resources folder. Don't make any resource folder inside /app folder since it is only a location to store code. Same goes with other specific folders. Then you can use
import play.Play;
Play.application().getFile("relative_path_from_<Project_Root>);
to access the file inside your code.
Only this, will work perfectly on dev environment. But once you put this in production using the dist file, it will not work since the entire resources folder you put will not be added to the dist. In order to do that, you have to explicitly ask play to add the /resources folder to your dist also. For that what you have to do is go to your /build.sbt and add these lines
import com.typesafe.sbt.packager.MappingsHelper._
mappings in Universal ++= directory(baseDirectory.value / "resources")
Now if you take and check your dist, you can see it has an additional folder 'resources' inside the dist. Then it will work for the production environment also.
来源：https://stackoverflow.com/questions/37180024/is-there-a-default-method-to-read-a-file-in-play-which-works-even-in-the-product