SpringDemoVerticle.java

package io.vertx.examples.spring.verticle;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.vertx.core.AbstractVerticle;
import io.vertx.core.Handler;
import io.vertx.core.eventbus.Message;
import io.vertx.core.json.Json;
import io.vertx.examples.spring.service.ProductService;
import org.springframework.context.ApplicationContext;


/**
 * Simple verticle to wrap a Spring service bean - note we wrap the service call
 * in executeBlocking, because we know it's going to be a JDBC call which blocks.
 * As a general principle with Spring beans, the default assumption should be that it will block unless you
 * know for sure otherwise (in other words use executeBlocking unless you know for sure your service call will be
 * extremely quick to respond)
 */
public class SpringDemoVerticle extends AbstractVerticle {

  public static final String ALL_PRODUCTS_ADDRESS = "example.all.products";

  // Reuse the Vert.x Mapper, alternatively you can use your own.
  private final ObjectMapper mapper = Json.mapper;

  private final ProductService service;

  public SpringDemoVerticle(final ApplicationContext context) {
    service = (ProductService) context.getBean("productService");
  }

  private Handler<Message<String>> allProductsHandler(ProductService service) {
    // It is important to use an executeBlocking construct here
    // as the service calls are blocking (dealing with a database)
    return msg -> vertx.<String>executeBlocking(future -> {
          try {
            future.complete(mapper.writeValueAsString(service.getAllProducts()));
          } catch (JsonProcessingException e) {
            System.out.println("Failed to serialize result");
            future.fail(e);
          }
        },
        result -> {
          if (result.succeeded()) {
            msg.reply(result.result());
          } else {
            msg.reply(result.cause().toString());
          }
        });
  }

  @Override
  public void start() throws Exception {
    super.start();
    vertx.eventBus().<String>consumer(ALL_PRODUCTS_ADDRESS).handler(allProductsHandler(service));
  }
}