HelloWorld for App Engine Standard (Java 21)

This sample demonstrates how to deploy an application on Google App Engine.

See the Google App Engine standard environment documentation for more detailed instructions.

• Java 21
• Maven (at least 3.5)
• Google Cloud SDK (aka gcloud)

Setup

• Download and initialize the Cloud SDK

gcloud init

• Create an App Engine app within the current Google Cloud Project

gcloud app create

• In the pom.xml, update the App Engine Maven Plugin with your Google Cloud Project Id:

<plugin>
  <groupId>com.google.cloud.tools</groupId>
  <artifactId>appengine-maven-plugin</artifactId>
  <version>2.8.0</version>
  <configuration>
    <projectId>myProjectId</projectId>
    <version>GCLOUD_CONFIG</version>
  </configuration>
</plugin>

Note: GCLOUD_CONFIG is a special version for autogenerating an App Engine version. Change this field to specify a specific version name.

Maven

Running locally

mvn package appengine:run

To use visit: http://localhost:8080/

Deploying

mvn package appengine:deploy

To use visit: https://YOUR-PROJECT-ID.appspot.com

Testing

mvn verify

As you add / modify the source code (src/main/java/...) it's very useful to add unit testing to (src/main/test/...). The following resources are quite useful:

• Junit4
• Mockito
• Truth

Gradle

Running locally

./gradlew appengineRun

To use vist: http://localhost:8080/

Deploying

./gradlew appengineDeploy