moved dealing with configuration to its own file, support for naming a different file and command line overrides

corefx/src/main/java/com/core/Controller.java

@@ -8,6 +8,7 @@ import com.core.rest.CoreApi;
 import com.core.rest.GetConfig;
 import com.core.rest.SetConfig;
 import com.core.ui.*;
+import com.core.utils.ConfigUtils;
 import com.core.websocket.CoreWebSocket;
 import javafx.application.Application;
 import javafx.application.Platform;
@@ -73,7 +74,7 @@ public class Controller implements Initializable {
 
     public Controller() {
         // load configuration
-        Properties properties = getConfiguration();
+        Properties properties = ConfigUtils.load();
         String coreUrl = properties.getProperty("core-rest");
         logger.info("core rest: {}", coreUrl);
 
@@ -197,17 +198,6 @@ public class Controller implements Initializable {
         }
     }
 
-    private Properties getConfiguration() {
-        try {
-            Properties properties = new Properties();
-            properties.load(getClass().getResourceAsStream("/config.properties"));
-            return properties;
-        } catch (IOException ex) {
-            logger.error("error reading config file");
-            throw new RuntimeException("configuration file did not exist");
-        }
-    }
-
     @Override
     public void initialize(URL location, ResourceBundle resources) {
         logger.info("controller initialize");

corefx/src/main/java/com/core/Main.java

@@ -22,7 +22,6 @@ public class Main extends Application {
         // load svg icons
         SVGGlyphLoader.loadGlyphsFont(getClass().getResourceAsStream("/icons/icomoon_material.svg"),
                 "icomoon.svg");
-        logger.info("icons: {}", SVGGlyphLoader.getAllGlyphsIDs());
 
         // load font
         Font.loadFont(getClass().getResourceAsStream("/font/roboto/Roboto-Regular.ttf"), 10);

corefx/src/main/java/com/core/utils/ConfigUtils.java

@@ -0,0 +1,40 @@
+package com.core.utils;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.IOException;
+import java.util.Properties;
+
+public final class ConfigUtils {
+    private static final Logger logger = LogManager.getLogger();
+    private static final String DEFAULT_CONFIG = "/config.properties";
+
+    private ConfigUtils() {
+
+    }
+
+    public static Properties load() {
+        String filePath = System.getProperty("config.file", DEFAULT_CONFIG);
+        logger.info("loading config file: {}", filePath);
+
+        try {
+            Properties properties = new Properties();
+            properties.load(ConfigUtils.class.getResourceAsStream(filePath));
+
+            // override values if provided
+            for (String key : properties.stringPropertyNames()) {
+                String value = System.getProperty(key);
+                if (value != null) {
+                    logger.info("command line config: {} - {}", key, value);
+                    properties.setProperty(key, value);
+                }
+            }
+
+            return properties;
+        } catch (IOException ex) {
+            logger.error("error reading config file");
+            throw new RuntimeException("configuration file did not exist");
+        }
+    }
+}