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？我目前只能将 ResultSet 输出到 System.out 控制台，但我无法将其保存到 java String。这是我所在位置的一个示例：

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?

我希望能够将 JSON 变量发送到另一个方法以对其执行一些工作。

提前致谢！

Answer 1

尝试写入ByteArrayOutputStream 并将其中的字节转换为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);