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    <p>Here's some example code. Note that I wouldn't actually do it this way for real: the presentation code and the back-end query handling are all mixed up in one class. Real apps don't do this! The example is faithful to your sample, except that rather than string-bash the query, I use Jena's facility to pre-bind some of the query variables (so <code>DIR1-NAME</code> becomes <code>?dir-1-name</code>). I think this is much cleaner, and gives you more flexibility as to which of the query parameters are passed in from the client.</p> <pre><code>package example; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.*; import com.hp.hpl.jena.query.*; import com.hp.hpl.jena.rdf.model.*; public class ServletExample extends HttpServlet { /***********************************/ /* Constants */ /***********************************/ private static final long serialVersionUID = 1L; public static final String SPARQL_ENDPOINT = "http://data.linkedmdb.org/sparql"; public static final String QUERY = "PREFIX m: &lt;http://data.linkedmdb.org/resource/movie/&gt;\n" + "SELECT DISTINCT ?actorName WHERE {\n" + " ?dir1 m:director_name %dir_name_1%.\n" + " ?dir2 m:director_name %dir_name_2%.\n" + " ?dir1film m:director ?dir1;\n" + " m:actor ?actor.\n" + " ?dir2film m:director ?dir2;\n" + " m:actor ?actor.\n" + " ?actor m:actor_name ?actorName.\n" + "}\n" + ""; private static final String HEADER = "&lt;html&gt;\n" + " &lt;head&gt;\n" + " &lt;title&gt;results&lt;/title&gt;\n" + " &lt;link href=\"simple.css\" type=\"text/css\" rel=\"stylesheet\" /&gt;\n" + " &lt;/head&gt;\n" + " &lt;body&gt;\n" + ""; private static final String FOOTER = "&lt;/body&gt;&lt;/html&gt;"; /** * Respond to HTTP GET request. Will need to be mounted against some URL * pattern in web.xml */ @Override protected void doGet( HttpServletRequest req, HttpServletResponse resp ) throws ServletException, IOException { String dir1 = req.getParameter( "dir1" ); String dir2 = req.getParameter( "dir2" ); if (dir1 == null || dir2 == null || dir1.isEmpty() || dir2.isEmpty()) { noInput( resp ); } else { runQuery( resp, dir1, dir2 ); } } protected void noInput( HttpServletResponse resp ) throws IOException { header( resp ); resp.getWriter().println( "&lt;p&gt;Please select director names as query params &lt;code&gt;dir1&lt;/code&gt; and &lt;code&gt;dir2&lt;/code&gt;&lt;/p&gt;" ); footer( resp ); } protected void footer( HttpServletResponse resp ) throws IOException { resp.getWriter().println( FOOTER ); } protected void header( HttpServletResponse resp ) throws IOException { resp.getWriter().println( HEADER ); } protected void runQuery( HttpServletResponse resp, String dir1, String dir2 ) throws IOException { PrintWriter out = resp.getWriter(); // Set up the query String q = QUERY.replace( "%dir_name_1%", "\"" + dir1 + "\"" ) .replace( "%dir_name_2%", "\"" + dir2 + "\"" ); Query query = QueryFactory.create( q ) ; QueryExecution qexec = QueryExecutionFactory.sparqlService( SPARQL_ENDPOINT, query ); // perform the query ResultSet results = qexec.execSelect(); // generate the output header( resp ); if (!results.hasNext()) { out.println( "&lt;p&gt;No results, sorry.&lt;/p&gt;" ); } else { out.println( "&lt;h1&gt;Results&lt;/h1&gt;" ); while (results.hasNext()) { QuerySolution qs = results.next(); String actorName = qs.getLiteral( "actorName" ).getLexicalForm(); out.println( String.format( "&lt;div&gt;Actor named: %s&lt;/div&gt;", actorName ) ); } } footer( resp ); } } </code></pre> <p>This code works as far as I can tell, but I don't know which queries you're using that should return some results.</p>
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    1. COI have'nt run the code yet,but it seems that there is no statement in the code that passes the query to sparql endpoint as in the original code.
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    2. COYou're right, sorry. I've fixed the code now (hopefully)
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    3. COOK, I was wrong about using the QuerySolutionMap approach for fixing some of the bindings. This works very well for querying a local Jena model (including a persistent model, such as TDB), but doesn't work when querying a remote service. So back to string bashing! Not knowing the test queries you're using, I can't verify that this works as expected - my (guessed) test queries return no results.
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