Add transaction accessor in Connection eclipse-vertx#646

vertx-sql-client/src/main/java/io/vertx/sqlclient/SqlConnection.java

@@ -68,7 +68,7 @@ public interface SqlConnection extends SqlClient {
    * Begin a transaction and returns a {@link Transaction} for controlling and tracking
    * this transaction.
    * <p/>
-   * When the connection is explicitely closed, any inflight transaction is rollbacked.
+   * When the connection is explicitely closed, any inflight transaction is rolled back.
    */
   void begin(Handler<AsyncResult<Transaction>> handler);
 
@@ -77,6 +77,13 @@ public interface SqlConnection extends SqlClient {
    */
   Future<Transaction> begin();
 
+  /**
+   * If @{link {@link #begin()} or {#link {@link #begin(Handler)} has been called, returns
+   * the associated transaction. Returns null otherwise.
+   * @return the current associated transaction, or null.
+   */
+  Transaction currentTransaction();
+
   /**
    * @return whether the connection uses SSL
    */

vertx-sql-client/src/main/java/io/vertx/sqlclient/impl/SqlConnectionImpl.java

@@ -54,6 +54,11 @@ public void handleClosed() {
     }
   }
 
+  @Override
+  public Transaction currentTransaction() {
+      return tx;
+  }
+
   @Override
   public <R> void schedule(CommandBase<R> cmd, Promise<R> promise) {
     if (tx != null) {