traffic-provbz: add logging for failed request

data-collectors/traffic-provBZ/src/main/java/it/bz/odh/trafficprovbz/FamasClient.java

@@ -120,13 +120,19 @@ public AggregatedDataDto[] getAggregatedDataOnStations(String stationId, String
 		payload.put("IdPostazioni", stationIdArray);
 		payload.put("InizioPeriodo", startPeriod);
 		payload.put("FinePeriodo", endPeriod);
-		StringEntity stringEntity = new StringEntity(String.valueOf(payload),
+		String payloadString = payload.toJSONString();
+		StringEntity stringEntity = new StringEntity(payloadString,
 				ContentType.APPLICATION_JSON);
 		HttpPost request = new HttpPost(aggregatedDataOnStationsUrl);
 		request.setEntity(stringEntity);
-		HttpEntity entity = client.execute(request).getEntity();
-		String responseString = EntityUtils.toString(entity, RESPONSE_CHARSET);
-		return objectMapper.readValue(responseString, AggregatedDataDto[].class);
+		try {
+			HttpEntity entity = client.execute(request).getEntity();
+			String responseString = EntityUtils.toString(entity, RESPONSE_CHARSET);
+			return objectMapper.readValue(responseString, AggregatedDataDto[].class);
+		} catch (Exception e) {
+			LOG.error("Dumping request object: " + payloadString);
+			throw e;
+		}
 	}
 
 	/**