Load real driver class before use

src/main/java/com/amazonaws/secretsmanager/sql/AWSSecretsManagerDriver.java

@@ -176,6 +176,20 @@ private void setProperties() {
         this.realDriverClass = this.config.getStringPropertyWithDefault("realDriverClass", getDefaultDriverClass());
     }
 
+    /**
+     * Loads the real driver.
+     *
+     * @throws IllegalStateException                            When there is no class with the name
+     *                                                          <code>realDriverClass</code>
+     */
+    private void loadRealDriver() {
+        try {
+            Class.forName(this.realDriverClass);
+        } catch (ClassNotFoundException e) {
+            throw new IllegalStateException("Could not load real driver with name, \"" + this.realDriverClass + "\".", e);
+        }
+    }
+
     /**
      * Called when the driver is deregistered to cleanup resources.
      */
@@ -234,6 +248,7 @@ private String unwrapUrl(String jdbcUrl) {
      *                                                          <code>realDriverClass</code>
      */
     public Driver getWrappedDriver() {
+        loadRealDriver();
         Enumeration<Driver> availableDrivers = DriverManager.getDrivers();
         while (availableDrivers.hasMoreElements()) {
             Driver driver = availableDrivers.nextElement();