@Override public TransactionHandler getTransactionHandler() { if (th == null) th = new FileGraphTransactionHandler( this ); return th; }
@Override public void begin() { if (inTransaction) throw new JenaException( "nested transactions not supported" ); else { checkPointFile = new File( checkPointName( fileGraph.name ) ); checkPointFile.deleteOnExit(); fileGraph.saveContents( checkPointFile ); inTransaction = true; } }