Fix closing connection on invalid connection

src/de/steamwar/sql/internal/Statement.java

@@ -157,32 +157,36 @@ public class Statement implements AutoCloseable {
 
     private <T> T withConnection(SQLRunnable<T> runnable, Object... objects) {
         Connection connection = aquireConnection();
+        T result;
 
         try {
-            try {
+            result = tryWithConnection(connection, runnable, objects);
-                return tryWithConnection(connection, runnable, objects);
+        } catch (Throwable e) {
-            } finally {
             if(connectionInvalid(connection)) {
                 closeConnection(connection);
+
+                return withConnection(runnable, objects);
             } else {
                 synchronized (connections) {
                     connections.push(connection);
                     connections.notify();
                 }
-                }
+
-            }
-        } catch (SQLException e) {
-            if(connectionInvalid(connection)) {
-                return withConnection(runnable, objects);
-            } else {
                 throw new SecurityException("Failing sql statement", e);
             }
         }
+
+        synchronized (connections) {
+            connections.push(connection);
+            connections.notify();
+        }
+
+        return result;
     }
 
     private boolean connectionInvalid(Connection connection) {
         try {
-            return connection.isClosed();
+            return connection.isClosed() || !connection.isValid(1);
         } catch (SQLException e) {
             logger.log(Level.INFO, "Could not check SQL connection status", e); // No database logging possible at this state
             return true;