More code review fixes

spring/integration/pubsub/src/main/java/com/example/spring/pubsub/PubsubApplication.java

@@ -1,18 +1,18 @@
 package com.example.spring.pubsub;
 
-import com.google.pubsub.v1.Subscription;
-import com.google.pubsub.v1.SubscriptionName;
-import com.google.pubsub.v1.Topic;
-import com.google.pubsub.v1.TopicName;
 import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import com.google.cloud.pubsub.v1.AckReplyConsumer;
 import com.google.protobuf.ByteString;
-
-import java.util.List;
-import java.util.stream.Collectors;
+import com.google.pubsub.v1.Subscription;
+import com.google.pubsub.v1.SubscriptionName;
+import com.google.pubsub.v1.Topic;
+import com.google.pubsub.v1.TopicName;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.SpringApplication;
@@ -22,8 +22,6 @@
 import org.springframework.cloud.gcp.pubsub.support.GcpHeaders;
 import org.springframework.cloud.gcp.pubsub.support.SubscriberFactory;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.ComponentScan;
-import org.springframework.integration.annotation.IntegrationComponentScan;
 import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.annotation.ServiceActivator;
 import org.springframework.integration.channel.PublishSubscribeChannel;
@@ -39,9 +37,7 @@
 import org.springframework.web.servlet.view.RedirectView;
 
 @SpringBootApplication
-@IntegrationComponentScan
 @RestController
-@ComponentScan(basePackages = {"org.springframework.cloud.gcp"})
 public class PubsubApplication {
 
   private static final Log LOGGER = LogFactory.getLog(PubsubApplication.class);
@@ -110,7 +106,7 @@ public PubsubInboundChannelAdapter messageChannelAdapter(
 
   @Bean
   @ServiceActivator(inputChannel = "pubsubInputChannel")
-  public MessageHandler receiveMessage() {
+  public MessageHandler messageReceiver1() {
     return message -> {
       LOGGER.info("Message arrived! Payload: "
           + ((ByteString) message.getPayload()).toStringUtf8());
@@ -122,7 +118,7 @@ public MessageHandler receiveMessage() {
 
   @Bean
   @ServiceActivator(inputChannel = "pubsubInputChannel")
-  public MessageHandler receiveMessageInParallel() {
+  public MessageHandler messageReceiver2() {
     return message -> {
       LOGGER.info("Message also arrived here! Payload: "
           + ((ByteString) message.getPayload()).toStringUtf8());
@@ -134,17 +130,12 @@ public MessageHandler receiveMessageInParallel() {
 
   @Bean
   @ServiceActivator(inputChannel = "pubsubOutputChannel")
-  public MessageHandler messageSender(PubsubTemplate pubsubTemplate) throws IOException {
+  public MessageHandler messageSender(PubsubTemplate pubsubTemplate) {
     PubsubMessageHandler outboundAdapter = new PubsubMessageHandler(pubsubTemplate);
     outboundAdapter.setTopic("test");
     return outboundAdapter;
   }
 
-  @Bean
-  public MessageChannel pubsubOutputChannel() {
-    return new PublishSubscribeChannel();
-  }
-
   @MessagingGateway(defaultRequestChannel = "pubsubOutputChannel")
   public interface PubsubOutboundGateway {
 

spring/integration/pubsub/src/main/resources/application.properties

@@ -0,0 +1,5 @@
+#spring.cloud.gcp.projectId=[YOUR_PROJECT_ID]
+#spring.cloud.gcp.credentialsLocation=file:[LOCAL_PATH_TO_CREDENTIALS]
+#
+#spring.cloud.gcp.pubsub.subscriber.executorThreads=[SUBSCRIBER_THREADS]
+#spring.cloud.gcp.pubsub.publisher.executorThreads=[PUBLISHER_THREADS]