Events endpoint PoC

Author: cardil

quarkus/src/main/java/com/redhat/openshift/knative/showcase/events/Endpoint.java

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+package com.redhat.openshift.knative.showcase.events;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.cloudevents.CloudEvent;
+import io.cloudevents.core.builder.CloudEventBuilder;
+import io.cloudevents.http.restful.ws.StructuredEncoding;
+import io.cloudevents.jackson.JsonFormat;
+import io.quarkus.runtime.StartupEvent;
+import io.smallrye.mutiny.Multi;
+import org.eclipse.microprofile.openapi.annotations.Operation;
+import org.jboss.resteasy.reactive.RestStreamElementType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.enterprise.event.Observes;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.random.RandomGenerator;
+
+@Path("events")
+@ApplicationScoped
+class Endpoint {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(Endpoint.class);
+  private final List<CloudEvent> events = new ArrayList<>();
+
+  void init(@Observes StartupEvent ignored, ObjectMapper om)
+    throws JsonProcessingException {
+    var rg = RandomGenerator.getDefault();
+    for (int i = 0; i < 3; i++) {
+      var s = Score.random(rg);
+      events.add(CloudEventBuilder.v1()
+        .withId(String.valueOf(i))
+        .withSource(URI.create("//localhost/dev"))
+        .withType(Endpoint.class.getName())
+        .withData(MediaType.APPLICATION_JSON, om.writeValueAsBytes(s))
+        .build());
+    }
+  }
+
+  @GET
+  @Operation(summary = "Retrieves all registered events as a JSON stream")
+  @RestStreamElementType(MediaType.APPLICATION_JSON)
+  @StructuredEncoding(JsonFormat.CONTENT_TYPE)
+  public Multi<CloudEvent> events() {
+    return Multi.createFrom().iterable(events);
+  }
+
+  @GET
+  @Path("last")
+  @Produces(MediaType.APPLICATION_JSON)
+  @StructuredEncoding(JsonFormat.CONTENT_TYPE)
+  public CloudEvent last() {
+    return events.get(events.size() - 1);
+  }
+
+  @POST
+  @Consumes(MediaType.APPLICATION_JSON)
+  @Operation(summary = "Receives a CloudEvent and stores it")
+  public void receive(CloudEvent event) {
+    events.add(event);
+    LOGGER.info("Received event: {}", event);
+  }
+
+  private static final class Score {
+    @JsonProperty
+    Play play;
+    @JsonProperty
+    int score;
+
+    static Score random(RandomGenerator rg) {
+      var s = new Score();
+      s.score = rg.nextInt(1_000);
+      s.play = new Play();
+      s.play.id = new UUID(rg.nextLong(), rg.nextLong()).toString();
+      s.play.game = rg.nextInt(300);
+      return s;
+    }
+  }
+
+  private static class Play {
+    @JsonProperty
+    String id;
+    @JsonProperty
+    Integer game;
+  }
+}