我在Google App Engine上部署了spring-boot + reactjs Web应用程序。执行“ mvn appengine：run”命令后，我尝试访问该站点，但显示“错误403” 有人，请帮助我解决这个问题。 在Cloud Shell上：
[INFO] No sources to compile
[INFO]
[INFO] --- maven-surefire-plugin:2.21.0:test (default-test) @ polls ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-war-plugin:3.1.0:war (default-war) @ polls ---
[INFO] Packaging webapp
[INFO] Assembling webapp [polls] in [/home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT]
[INFO] Processing war project
[INFO] Copying webapp webResources [/home/info/myexamples/SyneBiz/WebContent/WEB-INF] to [/home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT]
[INFO] Webapp assembled in [2411 msecs]
[INFO] Building war: /home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT.war
[INFO]
[INFO] <<< appengine-maven-plugin:1.3.2:run (default-cli) < package @ polls <<<
[INFO]
[INFO]
[INFO] --- appengine-maven-plugin:1.3.2:run (default-cli) @ polls ---
Dec 25, 2018 6:48:27 PM com.google.cloud.tools.appengine.cloudsdk.CloudSdk logCommand
INFO: submitting command: /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java -Duse_jetty9_runtime=true -D--enable_all_permissions=true -Dappengine.sdk.root=/google/google-cloud-sdk/platform/google_appengine/google/appengine/tools/java -cp /google/google-cloud-sdk/platform/google_appengine/google/appengine/tools/java/lib/appengine-tools-api.jar com.google.appengine.tools.development.DevAppServerMain --allow_remote_shutdown --disable_update_check --no_java_agent /home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT
[INFO] GCLOUD: 2018-12-25 18:48:28.100:INFO::main: Logging initialized @856ms to org.eclipse.jetty.util.log.StdErrLog
[INFO] GCLOUD: 2018-12-25 18:48:28.209:WARN:oejs.AbstractConnector:main: Ignoring deprecated socket close linger time
[INFO] GCLOUD: 2018-12-25 18:48:28.845:INFO:oejs.Server:main: jetty-9.4.14.v20181114; built: 2018-11-14T21:20:31.478Z; git: c4550056e785fb5665914545889f21dc136ad9e6; jvm 1.8.0_181-8u181-b13-2~deb9u1-b13
[INFO] GCLOUD: 2018-12-25 18:48:34.263:INFO:oeja.AnnotationConfiguration:main: Scanning elapsed time=4801ms
[INFO] GCLOUD: Dec 25, 2018 10:48:34 AM com.google.appengine.tools.development.ApiProxyLocalImpl log
[INFO] GCLOUD: INFO: javax.servlet.ServletContext log: 1 Spring WebApplicationInitializers detected on classpath
[INFO] GCLOUD: 2018-12-25 18:48:35.118:INFO:oejsh.ContextHandler:main: Started c.g.a.t.d.j.DevAppEngineWebAppContext@4032d386{/,file:///home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT/,AVAILABLE}{/home/info/myexamples/SyneBiz/target/polls-0.0.1-SNAPSHOT}
[INFO] GCLOUD: 2018-12-25 18:48:35.127:INFO:oejs.session:main: DefaultSessionIdManager workerName=node0
[INFO] GCLOUD: 2018-12-25 18:48:35.133:INFO:oejs.session:main: node0 Scavenging disabled
[INFO] GCLOUD: 2018-12-25 18:48:35.159:INFO:oejs.AbstractConnector:main: Started NetworkTrafficSelectChannelConnector@78aa1f72{HTTP/1.1,[http/1.1]}{localhost:8080}
[INFO] GCLOUD: 2018-12-25 18:48:35.166:INFO:oejs.Server:main: Started @7929ms
[INFO] GCLOUD: Dec 25, 2018 10:48:35 AM com.google.appengine.tools.development.AbstractModule startup
[INFO] GCLOUD: INFO: Module instance default is running at http://localhost:8080/
[INFO] GCLOUD: Dec 25, 2018 10:48:35 AM com.google.appengine.tools.development.AbstractModule startup
[INFO] GCLOUD: INFO: The admin console is running at http://localhost:8080/_ah/admin
[INFO] GCLOUD: Dec 25, 2018 6:48:35 PM com.google.appengine.tools.development.DevAppServerImpl doStart
[INFO] GCLOUD: INFO: Dev App Server is now running