Added config utility

src/main/java/de/rwu/easydrop/util/ConfigUtil.java

@@ -0,0 +1,49 @@
+package de.rwu.easydrop.util;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.NoSuchElementException;
+import java.util.Properties;
+
+/**
+ * Allows access to the config.
+ *
+ * @since 0.1.0
+ */
+public final class ConfigUtil {
+    /**
+     * Config file location.
+     */
+    private static final String CONFIG_LOCATION = "config/config.properties";
+
+    /**
+     * Private constructor to prevent unwanted instantiation.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    private ConfigUtil() throws UnsupportedOperationException {
+        throw new UnsupportedOperationException("This is a utility class, don't instantiate it.");
+    }
+
+    /**
+     * Returns a config value by specified key.
+     *
+     * @param key Config Key, like "API_KEY"
+     * @return Config value
+     */
+    public static String getConfig(final String key) {
+        Properties config = new Properties();
+        try (FileInputStream input = new FileInputStream(CONFIG_LOCATION)) {
+            config.load(input);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        String value = config.getProperty(key);
+        if (value == null) {
+            throw new NoSuchElementException("Requested config value does not exist");
+        }
+
+        return value;
+    }
+}