Java 语义网编程系列五: Jena+sparql实现语义数据查询

Sparql 是语义网的查询语言，是w3c推荐的一个标准,一下演示了之前设计的本体文件的查询，实现了"benz"车拥有者的姓名的查询。

/**
 
 * 语义数据查询
 
 * @param spaqrlString
 
 * @param queryModel
 
 * @param var
 
 */
 
     public void queryBySpaqrl( String spaqrlString , Model queryModel , String var )
 
             {
 
            Query query =         QueryFactory.create(spaqrlString);
 
            QueryExecution queryExecution = QueryExecutionFactory.create(query,queryModel);
 
            ResultSet resultSet = queryExecution.execSelect();
 
            while(resultSet.hasNext())
 
                    {
 
                            QuerySolution querySolution = resultSet.nextSolution();
 
                            RDFNode rdfNode = querySolution.get(var);
 
                            System.out.println(var +" is " + rdfNode.toString());
 
                    }
 
             }

Sparql 语句

@Test
 
public void testJenaSparql()
 
{
 
JenaModelSpaqrl  jenaModelSpaqrl = new JenaModelSpaqrl();
 
jenaModel= new JenaModel();
 
StringBuffer querystringBuffer = new StringBuffer();
 
querystringBuffer.append("PREFIX s1" + ": <" + defaultNameSpace + ">");
 
querystringBuffer.append(
 
"select ?name" +
 
" where { " +
 
"?car s1:hasBrand \"Benz\"."+
 
"?car s1:hasOwner ?person."+
 
"?person s1:hasName ?name}"
 
);
 
jenaModelSpaqrl.queryBySpaqrl(querystringBuffer.toString(), jenaModel.createOntologyModel(OntModelSpec.OWL_DL_MEM, pathFile) ,"?name");
 
}