| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package tdb.examples; |
| |
| import org.apache.jena.atlas.lib.StrUtils; |
| import org.apache.jena.query.Dataset; |
| import org.apache.jena.system.Txn; |
| import org.apache.jena.tdb.TDBFactory; |
| import org.apache.jena.update.UpdateExecutionFactory; |
| import org.apache.jena.update.UpdateFactory; |
| import org.apache.jena.update.UpdateProcessor; |
| import org.apache.jena.update.UpdateRequest; |
| |
| /** |
| * Example of a WRITE transaction. |
| * See {@link Txn#executeRead}. |
| */ |
| public class ExTDB_Txn2 { |
| public static void main(String...argv) { |
| String directory = "MyDatabases/DB1"; |
| Dataset dataset = TDBFactory.createDataset(directory); |
| |
| // Start WRITE transaction. |
| // It's possible to read from the dataset inside the write transaction. |
| |
| // An application can have other Datasets, in the same JVM, |
| // tied to the same TDB database performing read |
| // transactions concurrently. If another write transaction |
| // starts, the call of dataset.begin(WRITE) blocks until |
| // existing writer finishes. |
| |
| // A WRITE transaction is |
| // dataset.begin(ReadWrite.READ); |
| // try { |
| // ... |
| // ... dataset.abort() or dataset.commit() |
| // } finally { dataset.end();} |
| // |
| |
| Txn.executeWrite(dataset, ()->{ |
| // Do a SPARQL Update. |
| String sparqlUpdateString = StrUtils.strjoinNL |
| ("PREFIX . <http://example/>" |
| ,"INSERT { :s :p ?now } WHERE { BIND(now() AS ?now) }" |
| ); |
| |
| execUpdate(sparqlUpdateString, dataset); |
| }); |
| } |
| |
| public static void execUpdate(String sparqlUpdateString, Dataset dataset) { |
| UpdateRequest request = UpdateFactory.create(sparqlUpdateString); |
| UpdateProcessor proc = UpdateExecutionFactory.create(request, dataset); |
| proc.execute(); |
| } |
| |
| } |