Fixes URL for HTTP example and adds snippets for MQTT.

Author: gguuss

iot/api-client/http_example/README.md

@@ -20,11 +20,12 @@ The following command summarizes the sample usage:
 ```
     mvn exec:java \
         -Dexec.mainClass="com.google.cloud.iot.examples.HttpExample" \
-        -Dexec.args="-project_id=my-iot-project \
-                     -registry_id=my-registry \
-                     -device_id=my-device \
-                     -private_key_file=rsa_private_pkcs8 \
-                     -algorithm=RS256"
+        -Dexec.args="-project_id=<your-iot-project> \
+                     -registry_id=<your-registry-id> \
+                     -device_id=<device-id> \
+                     -private_key_file=<path-to-keyfile> \
+                     -message_type=<event|state> \
+                     -algorithm=<RS256|ES256>"
 ```
 
 For example, if your project ID is `blue-jet-123`, your service account
@@ -42,6 +43,20 @@ provided in the parent folder, you can run the sample as:
                      -algorithm=RS256"
 ```
 
+To publish state messages, run the sample as follows:
+
+```
+    mvn exec:java \
+        -Dexec.mainClass="com.google.cloud.iot.examples.HttpExample" \
+        -Dexec.args="-project_id=blue-jet-123 \
+                     -registry_id=my-registry \
+                     -device_id=my-java-device \
+                     -private_key_file=../rsa_private_pkcs8 \
+                     -message_type=state \
+                     -algorithm=RS256"
+```
+
+
 ## Reading the messages written by the sample client
 
 1. Create a subscription to your topic.

iot/api-client/http_example/src/main/java/com/google/cloud/iot/examples/HttpExample.java

@@ -105,6 +105,8 @@ public static void publishMessage(String payload, String urlPath, String message
 
     String encPayload = encoder.encodeToString(payload.getBytes("UTF-8"));
 
+
+    urlPath = urlPath + devicePath + ":" + urlSuffix;
     URL url = new URL(urlPath);
     HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
     httpCon.setDoOutput(true);

iot/api-client/mqtt_example/src/main/java/com/google/cloud/iot/examples/MqttExample.java

@@ -14,6 +14,7 @@
 
 package com.google.cloud.iot.examples;
 
+// [START cloudiotcore_mqtt_imports]
 import io.jsonwebtoken.JwtBuilder;
 import io.jsonwebtoken.Jwts;
 import io.jsonwebtoken.SignatureAlgorithm;
@@ -26,6 +27,7 @@
 import org.eclipse.paho.client.mqttv3.MqttMessage;
 import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
 import org.joda.time.DateTime;
+// [END cloudiotcore_mqtt_imports]
 
 /**
  * Java sample of connecting to Google Cloud IoT Core vice via MQTT, using JWT.
@@ -52,7 +54,8 @@
  * </pre>
  */
 public class MqttExample {
-  /** Create a Cloud IoT Core JWT for the given project id, signed with the given private key. */
+  // [START cloudiotcore_mqtt_createjwt]
+  /** Create a Cloud IoT Core JWT for the given project id, signed with the given RSA key. */
   private static String createJwtRsa(String projectId, String privateKeyFile) throws Exception {
     DateTime now = new DateTime();
     // Create a JWT to authenticate this device. The device will be disconnected after the token
@@ -71,6 +74,7 @@ private static String createJwtRsa(String projectId, String privateKeyFile) thro
     return jwtBuilder.signWith(SignatureAlgorithm.RS256, kf.generatePrivate(spec)).compact();
   }
 
+  /** Create a Cloud IoT Core JWT for the given project id, signed with the given ES key. */
   private static String createJwtEs(String projectId, String privateKeyFile) throws Exception {
     DateTime now = new DateTime();
     // Create a JWT to authenticate this device. The device will be disconnected after the token
@@ -88,8 +92,11 @@ private static String createJwtEs(String projectId, String privateKeyFile) throw
 
     return jwtBuilder.signWith(SignatureAlgorithm.ES256, kf.generatePrivate(spec)).compact();
   }
+  // [END cloudiotcore_mqtt_createjwt]
 
+  /** Parse arguments, configure MQTT, and publish messages. */
   public static void main(String[] args) throws Exception {
+    // [START cloudiotcore_mqtt_configuremqtt]
     MqttExampleOptions options = MqttExampleOptions.fromFlags(args);
     if (options == null) {
       // Could not parse.
@@ -131,7 +138,9 @@ public static void main(String[] args) throws Exception {
       throw new IllegalArgumentException(
           "Invalid algorithm " + options.algorithm + ". Should be one of 'RS256' or 'ES256'.");
     }
+    // [END cloudiotcore_mqtt_configuremqtt]
 
+    // [START cloudiotcore_mqtt_publish]
     // Create a client, and connect to the Google MQTT bridge.
     MqttClient client = new MqttClient(mqttServerAddress, mqttClientId, new MemoryPersistence());
     try {
@@ -171,5 +180,6 @@ public static void main(String[] args) throws Exception {
       client.disconnect();
     }
     System.out.println("Finished loop successfully. Goodbye!");
+    // [END cloudiotcore_mqtt_publish]
   }
 }