Adding dependency and added url construct

pom.xml

@@ -40,6 +40,16 @@
       <artifactId>commons-cli</artifactId>
       <version>1.5.0</version>
     </dependency>
+    <dependency>
+      <groupId>org.mariadb.jdbc</groupId>
+      <artifactId>mariadb-java-client</artifactId>
+      <version>2.7.2</version>
+    </dependency>
+    <dependency>
+      <groupId>org.json</groupId>
+      <artifactId>json</artifactId>
+      <version>20210307</version>
+    </dependency>
   </dependencies>
 
   <build>

src/main/java/org/leolo/nrdatad/App.java

@@ -71,9 +71,12 @@ public class App {
         ) {
             log.atFatal().log("Unable to create instance of {}", databaseManagerClass);
             System.exit(1);
+            return;
         } catch (ClassCastException e){
             log.atFatal().log("{} is not a DatabaseManager", databaseManagerClass);
             System.exit(1);
+            return;
         }
+        config.getDatabaseManager().initPool();
     }
 }

src/main/java/org/leolo/nrdatad/db/mariadb/DatabaseManager.java

@@ -1,8 +1,30 @@
 package org.leolo.nrdatad.db.mariadb;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.leolo.nrdatad.ConfigurationManager;
+import org.mariadb.jdbc.MariaDbPoolDataSource;
+
 public class DatabaseManager implements org.leolo.nrdatad.db.DatabaseManager{
+    Logger logger = LogManager.getLogger();
+    private MariaDbPoolDataSource ds;
     @Override
     public void initPool() {
-
+        logger.atDebug().log("Start initialize the database pool");
+        ConfigurationManager conf = ConfigurationManager.getInstance();
+        if(
+                !conf.containsKey("db.host")||
+                !conf.containsKey("db.user")||
+                !conf.containsKey("db.pwd")||
+                !conf.containsKey("db.name")
+        ) {
+            logger.atFatal().log("Missing required property");
+            System.exit(1);
+            return;
+        }
+        String url = "jdbc:mariadb://"+conf.getProperty("db.host")+
+                ":"+conf.getProperty("db.port", "3306")+
+                "/"+conf.getProperty("db.name");
+        logger.atDebug().log("URL={}",url);
     }
 }