| /* |
| * 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 org.apache.jena.rdfconnection.examples; |
| |
| import org.apache.jena.query.*; |
| import org.apache.jena.rdfconnection.RDFConnection; |
| import org.apache.jena.rdfconnection.RDFConnectionFactory; |
| import org.apache.jena.riot.Lang; |
| import org.apache.jena.riot.RDFDataMgr; |
| import org.apache.jena.system.Txn; |
| |
| /* |
| * Example of a connection performng a number of transactional operations. |
| */ |
| public class RDFConnectionExample2 { |
| public static void main(String ...args) { |
| Query query = QueryFactory.create("SELECT * { {?s ?p ?o } UNION { GRAPH ?g { ?s ?p ?o } } }"); |
| Dataset dataset = DatasetFactory.createTxnMem(); |
| |
| try ( RDFConnection conn = RDFConnectionFactory.connect(dataset) ) { |
| System.out.println("** Load a file"); |
| // ---- Transaction 1: load data. |
| Txn.executeWrite(conn, ()->conn.load("data.ttl")); |
| |
| // ---- Transaction 2: explicit styles |
| conn.begin(ReadWrite.WRITE); |
| conn.load("http://example/g0", "data.ttl"); |
| |
| System.out.println("** Inside multistep transaction - query dataset"); |
| conn.queryResultSet(query, ResultSetFormatter::out); |
| |
| conn.abort(); |
| conn.end(); |
| System.out.println("** After abort 1"); |
| |
| // ---- Transaction 3: explicit styles |
| Txn.executeWrite(conn, ()->{ |
| conn.load("http://example/g0", "data.ttl"); |
| System.out.println("** Inside multistep transaction - fetch dataset"); |
| Dataset ds2 = conn.fetchDataset(); |
| RDFDataMgr.write(System.out, ds2, Lang.TRIG); |
| conn.abort(); |
| }); |
| |
| System.out.println("** After abort 2"); |
| // Only default graph showing. |
| conn.queryResultSet(query, ResultSetFormatter::out); |
| } |
| } |
| } |