in app-maven-plugin/src/main/java/com/google/cloud/tools/maven/stage/Stager.java [30:42]
static Stager newStager(AbstractStageMojo stageMojo) throws MojoExecutionException {
if (!stageMojo.isAppEngineCompatiblePackaging()) {
return new NoOpStager();
}
if (stageMojo.getArtifact() == null || !Files.exists(stageMojo.getArtifact())) {
throw new MojoExecutionException(
"\nCould not determine appengine environment, did you package your application?"
+ "\nRun 'mvn package appengine:stage'");
}
return stageMojo.isAppEngineWebXmlBased()
? AppEngineWebXmlStager.newAppEngineWebXmlStager(stageMojo)
: AppYamlStager.newAppYamlStager(stageMojo);
}