| /** |
| * 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.query.ReadWrite ; |
| import org.apache.jena.tdb.TDBFactory ; |
| import org.apache.jena.update.GraphStore ; |
| import org.apache.jena.update.GraphStoreFactory ; |
| 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. */ |
| 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 datet 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. |
| |
| dataset.begin(ReadWrite.WRITE) ; |
| try |
| { |
| GraphStore graphStore = GraphStoreFactory.create(dataset) ; |
| // Do a SPARQL Update. |
| String sparqlUpdateString = StrUtils.strjoinNL( |
| "PREFIX . <http://example/>", |
| "INSERT { :s :p ?now } WHERE { BIND(now() AS ?now) }" |
| ) ; |
| |
| execUpdate(sparqlUpdateString, graphStore) ; |
| dataset.commit() ; |
| // Or call .abort() |
| |
| } finally |
| { |
| // Notify the end of the transaction. |
| // The transaction was finished at the point .commit or .abort was called. |
| // .end will force an abort() if no previous call to .commit() or .abort() |
| // has occurred, so .end() help manage track the state of the transaction. |
| // .end() can be called multiple times for the same .begin(WRITE) |
| dataset.end() ; |
| } |
| } |
| |
| public static void execUpdate(String sparqlUpdateString, GraphStore graphStore) |
| { |
| UpdateRequest request = UpdateFactory.create(sparqlUpdateString) ; |
| UpdateProcessor proc = UpdateExecutionFactory.create(request, graphStore) ; |
| proc.execute() ; |
| } |
| |
| } |
| |