VirtTipsAndTricksGuideMultithreadJDBCHow can I make Multi Thread Virtuoso connection using JDBC?How can I make Multi Thread Virtuoso connection using JDBC? This sample demonstrates simple java code for performing Multi Thread Virtuoso connection using JDBC. It starts 3 threads: one thread executes SPARQL select and two threads execute SPARQL inserts: import java.util.*; import java.sql.*; import java.math.*; public class MTtest extends Thread { int mode = 0; int startId = 0; static String urlDB = "jdbc:virtuoso://localhost:1111"; public MTtest(int _mode, int _init) { mode = _mode; startId = _init; } void prnRs(ResultSet rs) { try { ResultSetMetaData rsmd; System.out.println(">>>>>>>>"); rsmd = rs.getMetaData(); int cnt = rsmd.getColumnCount(); while(rs.next()) { Object o; System.out.print("Thread:"+Thread.currentThread().getId()+" "); for (int i = 1; i <= cnt; i++) { o = rs.getObject(i); if (rs.wasNull()) System.out.print("<NULL> "); else System.out.print("["+ o + "] "); } System.out.println(); } } catch (Exception e) { System.out.println(e); e.printStackTrace(); } System.out.println(">>>>>>>>"); } public static void main(String argv[]) { try { Class.forName("virtuoso.jdbc3.Driver"); Connection conn = DriverManager.getConnection(urlDB,"dba","dba"); Statement st = conn.createStatement(); st.execute("sparql clear graph <mttest>"); st.execute("sparql insert into graph <mttest> { <xxx> <P01> \"test1\" }"); st.execute("sparql insert into graph <mttest> { <xxx> <P01> \"test2\" }"); st.execute("sparql insert into graph <mttest> { <xxx> <P01> \"test3\" }"); st.execute("sparql insert into graph <mttest> { <xxx> <P01> \"test4\" }"); st.execute("sparql insert into graph <mttest> { <xxx> <P01> \"test5\" }"); conn.close(); int init = 0; for(int i=0; i < 2; i++) { MTtest thr1 = new MTtest(1, init); init+=10; MTtest thr2 = new MTtest(0, init); init+=10; MTtest thr3 = new MTtest(0, init); init+=10; thr1.start(); thr2.start(); thr3.start(); thr1.join(); thr2.join(); thr3.join(); } System.out.println("===End==="); } catch (Exception e) { System.out.print(e); e.printStackTrace(); } } public void run( ) { try { Connection conn = DriverManager.getConnection(urlDB,"dba","dba"); Statement st; st = conn.createStatement(); if (mode == 1) { String query = "sparql SELECT * from <mttest> WHERE {?s ?p ?o}"; ResultSet rs = st.executeQuery(query); prnRs(rs); } else { long id = Thread.currentThread().getId(); for (int i =0; i < 5; i++) st.execute("sparql insert into graph <mttest> { <xxx"+startId+"> <P"+id+"> \"test"+i+"\" }"); System.out.println("\nThread:"+Thread.currentThread().getId()+" ===Rows Inserted==="); } conn.close(); } catch (SQLException e) { System.out.println("==========================================================="); System.out.println(">>["+e.getMessage()+"]"); System.out.println(">>["+e.getErrorCode()+"]"); System.out.println(">>["+e.getSQLState()+"]"); System.out.println(e); System.out.println("==========================================================="); e.printStackTrace(); System.exit(-1); } catch (Exception e) { System.out.println("==========================================================="); System.out.println(e); System.out.println("==========================================================="); e.printStackTrace(); System.exit(-1); } } // run( ) } Related Virtuoso Tips and Tricks Collection Virtuoso Driver for JDBC