//代码片段。df.show() 不起作用,因为它返回 void 并且不能附加到字符串
if(dbDataFinal.isEmpty())
log.info("Priority 1 query returned no results");
else
log.info("START_TS from first query: " + dbDataFinal.show());
return new HashMap<String, Dataset<Row>>() { { put("out", dbDataFinal); } };