问题
In Google App Engine (GAE), you can package multiple services into a single exploded WAR file (a.k.a EAR file) but only if your app is running under Java 7. This does not work for Java 8:
An App Engine application that uses services is organized as an unpacked Java Enterprise Archive (EAR) directory structure. The top-level EAR directory contains a single META-INF subdirectory, and a separate directory for each service in the app. Note that EAR is supported for the Java 7 runtime only, not for the Java 8 runtime.
I couldn't find anything in the GAE docs that indicates how you package multiple services into a single WAR file.
https://cloud.google.com/appengine/docs/standard/java/configuration-files
I realize that I can create a separate WAR file for each service but the local dev server supplied by Google for testing your app only accepts a single WAR file. I could run multiple instances of the dev server using different ports but that seems kind of messy.
回答1:
Google does have a solution but they documented in the most obscure location:
https://cloud.google.com/appengine/docs/standard/java/tools/migrate-gradle
It was easy to overlook this because the title of the document is:
Migrating to the Cloud SDK-based Gradle plugin
If you are building an app from scratch, you are not migrating anything and would easily skip this documentation. It should really have been documented at:
https://cloud.google.com/appengine/docs/standard/java/tools/gradle
Some additional instructions can be found at:
https://github.com/GoogleCloudPlatform/app-gradle-plugin/blob/master/USER_GUIDE.md
来源：https://stackoverflow.com/questions/48805469/packaging-multiple-services-into-a-war-file-for-java-8-in-gae