Use constants of strings

app/src/main/java/ch/luria/mq1/MqttService.java

@@ -19,6 +19,8 @@ public class MqttService extends Service {
     private Mqtt5AsyncClient client;
     private static final String TAG = "MQTT Service";
     private final IBinder binder = new LocalBinder();
+    private static final String mqttHost = "192.168.178.64";
+    private static final int mqttPort = 1883;
 
     public class LocalBinder extends Binder {
         public MqttService getService() {
@@ -34,8 +36,8 @@ public class MqttService extends Service {
             Log.i(TAG, "connecting");
             client = Mqtt5Client.builder()
                     .identifier(UUID.randomUUID().toString())
-                    .serverHost("192.168.178.64")
-                    .serverPort(1883)
+                    .serverHost(mqttHost)
+                    .serverPort(mqttPort)
                     .buildAsync();
         }
     }
@@ -93,7 +95,7 @@ public class MqttService extends Service {
         intent.setAction("ch.luria.mq1");
         try {
             final JSONObject obj = new JSONObject(msg);
-            String state = obj.getString("state");
+            String state = obj.getString(getString(R.string.mqtt_state_field));
             intent.putExtra("STATE", state);
             sendBroadcast(intent);
         } catch (JSONException e) {
@@ -129,7 +131,7 @@ public class MqttService extends Service {
     public void doToggle(boolean state) {
         JSONObject obj = new JSONObject();
         try {
-            obj.put("state", state ? "ON" : "OFF");
+            obj.put(getString(R.string.mqtt_state_field), state ? "ON" : "OFF");
             Log.i(TAG, "doToggle: " + obj);
             publishMessage(getString(R.string.mqtt_base_topic) + "/" + getString(R.string.mqtt_room_address) + "/set", obj.toString());
         } catch (JSONException e) {
@@ -140,7 +142,7 @@ public class MqttService extends Service {
     public void getStatus() {
         JSONObject obj = new JSONObject();
         try {
-            obj.put("state", "");
+            obj.put(getString(R.string.mqtt_state_field), "");
             Log.i(TAG, "getStatus()");
             publishMessage(getString(R.string.mqtt_base_topic) + "/" + getString(R.string.mqtt_room_address) + "/get", obj.toString());
         } catch (JSONException e) {

app/src/main/res/values/strings.xml

@@ -5,4 +5,5 @@
     <string name="room_name">Chambre d\'Isaac</string>
     <string name="mqtt_base_topic">zigbee2mqtt</string>
     <string name="mqtt_room_address">Ampoule Chambre Isaac</string>
+    <string name="mqtt_state_field">state</string>
 </resources>