A zerodep-web-push-java example using Spring WebFlux.

Also, this example demonstrates how to work with Reactor Netty HTTP Client

This example is sightly more complex but practical compared to zerodep-web-push-java-example and zerodep-web-push-java-example-vertx.

In this example, we demonstrate the error handling on requesting the delivery of push notifications.

This is the example for v2. The example for v1 is here.

• JDK17+
• A library for generating ECDSA key pairs(e.g. OpenSSL)
• A browser supporting Push API such as Google Chrome, Microsoft Edge and Firefox

1. Set up and run the application.

   git clone https://github.com/st-user/zerodep-web-push-java-example-webflux.git
   cd zerodep-web-push-java-example-webflux
   mkdir .keys
   cd .keys
   openssl ecparam -genkey -name prime256v1 -noout -out my-private.pem
   openssl pkcs8 -in my-private.pem -topk8 -nocrypt -out my-private_pkcs8.pem
   openssl ec -in my-private.pem -pubout -conv_form uncompressed -out my-pub.pem
   cd ../
   

   Linux/mac OS

   ./mvnw clean
   ./mvnw spring-boot:run
   

   Windows

   ./mvnw.cmd clean
   ./mvnw.cmd spring-boot:run
   

2. Open your browser and access http://localhost:8080;

3. Click the subscribe button.

4. Enter an arbitrary message and click the send button.

5. You should see a push notification!

6. (Optional) Since push notifications are handled in the background, we can get them even if we close the browser.

   • Close the browser and open a terminal instead.
   • Make the application send a push notification by using a command like the following:

   curl -X POST http://localhost:8080/sendMessage \  
   -H 'Content-Type: application/json' \
   -d '{ "message": "Message sent with curl." }'

In general, storing private keys in plain text on a file system is not recommended (In the above example, we do that for simplicity).

However, such a method is still useful depending on architectures.

For example:

• Using Secret Manager secrets in Cloud Run (Google Cloud)

  Mount each secret as a volume, which makes the secret available to the container as files.

• Push API - Web APIs | MDN
• Web Push Notifications: Timely, Relevant, and Precise

• zerodep-web-push-java-ext-jwt
• zerodep-web-push-java-example
• zerodep-web-push-java-example-vertx