org.apache.jena.tdb2.TDB2Factory Maven / Gradle / Ivy
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package org.apache.jena.tdb2;
import org.apache.jena.dboe.base.file.Location;
import org.apache.jena.query.Dataset;
import org.apache.jena.query.DatasetFactory;
import org.apache.jena.sparql.core.DatasetGraph;
import org.apache.jena.sparql.core.assembler.AssemblerUtils;
import org.apache.jena.sys.JenaSystem;
import org.apache.jena.tdb2.assembler.VocabTDB2;
/**
* Public factory for connecting to and creating datasets backed by TDB2 storage.
*/
public class TDB2Factory
{
static { JenaSystem.init(); }
private TDB2Factory() {}
/** Create or connect to a TDB2-backed dataset */
public static Dataset connectDataset(Location location) {
DatasetGraph dsg = DatabaseMgr.connectDatasetGraph(location);
return DatasetFactory.wrap(dsg);
}
/** Create or connect to a TDB2-backed dataset */
public static Dataset connectDataset(String location) {
return connectDataset(Location.create(location)); }
/**
* Create an in-memory TDB2-backed dataset (for testing). In-memory TDB2 datasets are use
* a simple simulation of disk I/O to give exact semantics, which is useful to create
* tests that run fast where setup and teardown of datasets can be the major cost.
*
* In-memory TDB2 datasets are not designed to scale, nor provide efficient execution for
* applications for long-term use.
*/
public static Dataset createDataset() { return connectDataset(Location.mem()); }
/**
* Read the file and assemble a dataset
*/
public static Dataset assembleDataset(String assemblerFile) {
return (Dataset)AssemblerUtils.build(assemblerFile, VocabTDB2.tDatasetTDB);
}
/** Test whether a dataset is backed by TDB or not. */
public static boolean isTDB2(Dataset dataset) {
return DatabaseMgr.isTDB2(dataset.asDatasetGraph());
}
/** Return the location of a dataset if it is backed by TDB, else null */
public static Location location(Dataset dataset) {
DatasetGraph dsg = dataset.asDatasetGraph();
return DatabaseMgr.location(dsg);
}
}