Make sure samples listen to PORT env var (#1598)

Author: averikitsch

appengine-java11/appengine-simple-jetty-main/src/main/java/com/example/appengine/demo/jettymain/Main.java

@@ -34,9 +34,6 @@ public static void main(String[] args) throws Exception {
 
     // Create a basic Jetty server object that will listen on port defined by
     // the PORT environment variable when present, otherwise on 8080.
-    // Note: If you set this to port 0, a randomly available port will be
-    // assigned. You can find the assigned port in the logs or programmatically
-    // obtain it.
     int port = Integer.parseInt(System.getenv().getOrDefault("PORT", "8080"));
     Server server = new Server(port);
 

appengine-java11/quarkus-helloworld/pom.xml

@@ -82,7 +82,7 @@
         <!-- Copy dependencies of exploded fatjar to appengine-staging directory -->
         <configuration>
           <libDir>${project.build.directory}/appengine-staging/lib</libDir>
-          <finalName>${project.build.directory}/appengine-staging/${build.finalName}</finalName>
+          <finalName>${project.build.directory}/appengine-staging/${project.build.finalName}</finalName>
         </configuration>
       </plugin>
       <!-- Set Surefire version to work with Junit5 -->

appengine-java11/quarkus-helloworld/src/main/resources/application.properties

@@ -0,0 +1,16 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Set the port to the PORT environment variable
+quarkus.http.port=${PORT:8080}

appengine-java11/springboot-helloworld/src/main/resources/application.properties

@@ -11,3 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+# Set the port to the PORT environment variable
+server.port=${PORT:8080}

appengine-java11/vertx-helloworld/src/main/java/com/example/appengine/vertxhello/Application.java

@@ -37,10 +37,13 @@ public void start(Future<Void> startFuture) {
     Router router = Router.router(vertx);
     router.route().handler(this::handleDefault);
 
+    // Get the PORT environment variable for the server object to listen on
+    int port = Integer.parseInt(System.getenv().getOrDefault("PORT", "8080"));
+
     vertx
         .createHttpServer()
         .requestHandler(router)
-        .listen(8080, ar -> startFuture.handle(ar.mapEmpty()));
+        .listen(port, ar -> startFuture.handle(ar.mapEmpty()));
   }
 
   private void handleDefault(RoutingContext routingContext) {