如何将JENA Sparql查询结果集保存为JSON？

Question

如何将JENA ResultSet存储为JSON格式的字符串？我目前只能够将ResultSet输出到System.out控制台，但我无法将其保存到java字符串中。这是我在其中一个例子：我希望能够到JSON变量发送到其他的方法来对它进行一些工作

QueryExecution qexec = QueryExecutionFactory.sparqlService(endpoint, query); 
ResultSet results = qexec.execSelect(); 
// the following prints out JSON in the System.out console: 
ResultSetFormatter.outputAsJSON(System.out, results); 
// but how do I save it as a String? 
// ie. 
String json = ResultSetFormatter.outputAsJSON(System.out, results); 
// obviously that doesn't work, but how would one get the equivalent working version? 

。

在此先感谢！

Answer 1

尝试写入ByteArrayOutputStream，并从该变换的字节到String

QueryExecution qexec = QueryExecutionFactory.sparqlService(sparqlEndpointQuery, query); 
ResultSet results = qexec.execSelect(); 

// write to a ByteArrayOutputStream 
ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); 

ResultSetFormatter.outputAsJSON(outputStream, results); 

// and turn that into a String 
String json = new String(outputStream.toByteArray()); 

System.out.println(json);