Add spring examples to readme + refactored the Liberty sample

Author: gfoster1

.gitignore

@@ -3,3 +3,7 @@ rest-nodejs-express-sample/node_modules
 *.classpath
 .project
 **.DS_Store
+
+*.iml
+.idea
+gradle*

README.md

@@ -1,5 +1,5 @@
 # event-streams-samples
-IBM Event Streams for IBM Cloud is a scalable, distributed, high throughput message bus to unite your on-premise and off-premise cloud technologies. You can wire micro-services together using open protocols, connect stream data to analytics to realise powerful insight and feed event data to multiple applications to react in real time.
+IBM Event Streams for IBM Cloud is a scalable, distributed, high throughput message bus to unite your on-premise and off-premise cloud technologies. You can wire micro-services together using open protocols, connect stream data to analytics to realize powerful insight and feed event data to multiple applications to react in real time.
 
 This repository is for samples which interact with the Event Streams for IBM Cloud service. 
 Currently, there are samples for the Kafka and MQ Light APIs.
@@ -11,13 +11,11 @@ The aim of the samples is to help you get started with Event Streams for IBM Clo
 ## Provisioning your Event Streams for IBM Cloud Cluster
 In order to provision an Event Streams for IBM Cloud cluster, please visit the [IBM Cloud® catalog](https://cloud.ibm.com/catalog/). Please also familiarise yourself with Event Streams for IBM Cloud and Apache Kafka basics and terminology. [Our documentation](https://cloud.ibm.com/docs/services/EventStreams?topic=eventstreams-getting_started) is a good starting point.
 
-
 ### Pricing plans
 IBM Event Streams can be provisioned on IBM Cloud® in various pricing plans. Please refer to our [documentation](https://cloud.ibm.com/docs/services/EventStreams?topic=eventstreams-plan_choose#plan_choose) to help choose a plan that works for you.
 
 __Important Note__: Provisioning an Event Streams service in IBM Cloud® incurs a fee. Please review pricing before provisioning. The samples in this repository will create topic(s) on your behalf - creating a topic might also incur a fee. For more information, please consult the IBM Cloud® documentation if necessary.
 
-
 ## Connecting to your Event Streams for IBM Cloud Cluster
 In each sample, we demonstrate a single connection path for both our Classic and Standard/Enterprise plans respectively. The aim was to get you started quickly. However your client's needs might be different. Therefore we wrote a [guide](https://cloud.ibm.com/docs/services/EventStreams?topic=eventstreams-connecting#connecting) that discusses credential generation in detail and showing you all possible ways of doing this.
 
@@ -31,6 +29,10 @@ In each sample, we demonstrate a single connection path for both our Classic and
 * [kafka-connect](/kafka-connect/README.md) : Sample Docker image with Kafka Connect
 * [kafka-mirrormaker](/kafka-mirrormaker/README.md) : Sample Docker image with Kafka Mirror Maker
 
+### Spring Kafka:
+* [spring kafka tutorial](https://developer.ibm.com/tutorials/use-spring-kafka-to-access-an-event-streams-service/) : Tutorial to quickly get you up and running using IBM Event Streams. 
+* [spring-kafka](https://github.com/wkorando/event-stream-kafka) : Sample app to connect to Event Streams using Spring Kafka
+
 ## Get Further Assistance
 
 If you have any issues, just ask us a question (tagged with `ibm-eventstreams`) on [StackOverflow.com](http://stackoverflow.com/questions/tagged/ibm-eventstreams).

kafka-java-liberty-sample/.gitignore

@@ -4,3 +4,8 @@
 /.gradle/
 /.settings/
 /.project
+
+#### intellij settings
+*.iml
+.idea
+gradle*

kafka-java-liberty-sample/src/main/java/com/eventstreams/samples/env/Environment.java

@@ -18,65 +18,55 @@
  * (c) Copyright IBM Corp. 2018
  */
 package com.eventstreams.samples.env;
-import java.io.IOException;
-import java.util.Iterator;
 
-import org.apache.kafka.common.errors.IllegalSaslStateException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
 
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.IOException;
+import java.util.Iterator;
 
 public class Environment {
 
     private static final Logger logger = Logger.getLogger(Environment.class);
-    private static final String SERVICE_NAME = "messagehub";
 
     public static EventStreamsCredentials getEventStreamsCredentials() {
         String vcapServices = System.getenv("VCAP_SERVICES");
         logger.log(Level.INFO, "VCAP_SERVICES: \n" + vcapServices);
-        try {
-            if (vcapServices != null) {
-                JsonNode mhub = parseVcapServices(vcapServices);
-                ObjectMapper mapper = new ObjectMapper();
-                return mapper.readValue(mhub.toString(), EventStreamsCredentials.class);
-            } else {
-                logger.log(Level.ERROR, "VCAP_SERVICES environment variable is null.");
-                throw new IllegalStateException("VCAP_SERVICES environment variable is null.");
-            }
-        } catch (IOException ioe) {
-            logger.log(Level.ERROR, "VCAP_SERVICES environment variable parses failed.");
-            throw new IllegalStateException("VCAP_SERVICES environment variable parses failed.", ioe);
+        if (vcapServices == null) {
+            logger.log(Level.ERROR, "VCAP_SERVICES environment variable is null.");
+            throw new IllegalStateException("VCAP_SERVICES environment variable is null.");
         }
+        return transformVcapServices(vcapServices);
     }
 
-    private static JsonNode parseVcapServices(String vcapServices) throws IOException {
-        ObjectMapper mapper = new ObjectMapper();
-        JsonNode vcapServicesJson = mapper.readValue(vcapServices, JsonNode.class);
-
-        // when running in CloudFoundry VCAP_SERVICES is wrapped into a bigger JSON object
-        // so it needs to be extracted. We attempt to read the "instance_id" field to identify
-        // if it has been wrapped
-        if (vcapServicesJson.get("instance_id") != null) {
-            return vcapServicesJson;
-        } else {
-            String vcapKey = null;
-            Iterator<String> it = vcapServicesJson.fieldNames();
-            // Find the Event Streams service bound to this application.
-            while (it.hasNext() && vcapKey == null) {
-                String potentialKey = it.next();
-                if (potentialKey.startsWith(SERVICE_NAME)) {
-                    logger.log(Level.WARN, "Using the '" + potentialKey + "' key from VCAP_SERVICES.");
-                    vcapKey = potentialKey;
+    private static EventStreamsCredentials transformVcapServices(String vcapServices) {
+        try {
+            ObjectMapper mapper = new ObjectMapper();
+            JsonNode instanceCredentials = mapper.readValue(vcapServices, JsonNode.class);
+            // when running in CloudFoundry VCAP_SERVICES is wrapped into a bigger JSON object
+            // so it needs to be extracted. We attempt to read the "instance_id" field to identify
+            // if it has been wrapped
+            if (instanceCredentials.get("instance_id") == null) {
+                Iterator<String> it = instanceCredentials.fieldNames();
+                // Find the Event Streams service bound to this application.
+                while (it.hasNext()) {
+                    String potentialKey = it.next();
+                    String messageHubJsonKey = "messagehub";
+                    if (potentialKey.startsWith(messageHubJsonKey)) {
+                        logger.log(Level.WARN, "Using the '" + potentialKey + "' key from VCAP_SERVICES.");
+                        instanceCredentials = instanceCredentials.get(potentialKey)
+                                .get(0)
+                                .get("credentials");
+                        break;
+                    }
                 }
             }
-
-            if (vcapKey == null) {
-                throw new IllegalSaslStateException("No EventStreams service bound");
-            } else {
-                return vcapServicesJson.get(vcapKey).get(0).get("credentials");
-            }
+            return mapper.readValue(instanceCredentials.toString(), EventStreamsCredentials.class);
+        } catch (IOException e) {
+            logger.log(Level.ERROR, "VCAP_SERVICES environment variable parses failed.");
+            throw new IllegalStateException("VCAP_SERVICES environment variable parses failed.", e);
         }
     }
 }