Below is the piece of code that causes OutOfMemory issue when I run my xyz.war in tomcat 7 with Java 8.
In Below code I am creating a CSV response of the data that was fetched from MongoDB via cursor.
@RequestMapping(value = "/elements/{elementname}/records", method = RequestMethod.GET) public ModelAndView getAllRecords( HttpServletRequest request, HttpServletResponse response, @RequestParam(value = "customerid", required = true) long customerId, @RequestParam(value = "userid", required = true) long userId, @RequestParam(value = "query", required = false) String query, throws Exception { Map < String, Object > model = new HashMap < String, Object > (); JsonObject records = elementService.searchRecords(query); ModelAndViewData msvd = elementService.commonRestService .getModelAndView("dataObject", "streamingView"); return new ModelAndView(msvd.getViewName(), handleCsvReportTypeRequest(records, customerId, userId)); } public Map < String, Object > handleCsvReportTypeRequest(JsonObject records, String elementName, long customerId, long userId) throws Exception { StringBuffer csvData = new StringBuffer(); // create csv data ModelAndViewData modelAndStreamingViewData = commonRestService.getModelAndView( "dataObject", "streamingView"); byte[] byteArray = String.valueOf(csvData).getBytes(); InputStream byteArrayInputStream = new ByteArrayInputStream(byteArray); model.put(modelAndStreamingViewData.getModelAttributeName(), byteArrayInputStream); model.put(DownloadConstants.CONTENT_TYPE, DownloadConstants.CSV_CONTENT_TYPE); model.put(DownloadConstants.FILENAME, "XYZ.csv"); model.put(DownloadConstants.LAST_MODIFIED, new Date(System.currentTimeMillis())); model.put(DownloadConstants.CONTENT_LENGTH, Integer.valueOf(byteArray.length)); return model; } How can I stream CSV data back to the user without creating a huge data in memory and then passing to the user?
