/**
* Decorates the given <code>updateItemRequest</code> with attributes required for geo spatial
* querying.
*
* @param attributeValueMap the items that needs to be decorated with geo attributes
* @param latitude the latitude that needs to be attached with the item
* @param longitude the longitude that needs to be attached with the item
* @param configs the collection of configurations to be used for decorating the request with geo
* attributes
*/
public void updateAttributeValues(
Map<String, AttributeValue> attributeValueMap,
double latitude,
double longitude,
List<GeoConfig> configs) {
if (configs == null) {
throw new IllegalArgumentException("Geo configs should not be null");
}
for (GeoConfig config : configs) {
// Fail-fast if any of the preconditions fail
checkConfigParams(
config.getGeoIndexName(),
config.getGeoHashKeyColumn(),
config.getGeoHashColumn(),
config.getGeoHashKeyLength());
long geohash = s2Manager.generateGeohash(latitude, longitude);
long geoHashKey = s2Manager.generateHashKey(geohash, config.getGeoHashKeyLength());
// Decorate the request with the geohash
AttributeValue geoHashValue = new AttributeValue().withN(Long.toString(geohash));
attributeValueMap.put(config.getGeoHashColumn(), geoHashValue);
AttributeValue geoHashKeyValue;
if (config.getHashKeyDecorator().isPresent()
&& config.getCompositeHashKeyColumn().isPresent()) {
AttributeValue compositeHashKeyValue =
attributeValueMap.get(config.getCompositeHashKeyColumn().get());
if (compositeHashKeyValue == null) {
continue;
}
String compositeColumnValue = compositeHashKeyValue.getS();
String hashKey =
config.getHashKeyDecorator().get().decorate(compositeColumnValue, geoHashKey);
// Decorate the request with the composite geoHashKey (type String)
geoHashKeyValue = new AttributeValue().withS(String.valueOf(hashKey));
} else {
// Decorate the request with the geoHashKey (type Number)
geoHashKeyValue = new AttributeValue().withN(String.valueOf(geoHashKey));
}
attributeValueMap.put(config.getGeoHashKeyColumn(), geoHashKeyValue);
}
}
/** @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String category = request.getParameter("category");
HashMap<String, Condition> scanFilter = new HashMap<String, Condition>();
Condition condition =
new Condition()
.withComparisonOperator(ComparisonOperator.NE.toString())
.withAttributeValueList(new AttributeValue().withN("0"));
Condition condition2 =
new Condition()
.withComparisonOperator(ComparisonOperator.NE.toString())
.withAttributeValueList(new AttributeValue().withN("0"));
Condition condition3 = new Condition().withComparisonOperator(ComparisonOperator.CONTAINS);
scanFilter.put("geoLat", condition);
scanFilter.put("geoLng", condition2);
if (category != null && !category.isEmpty()) {
condition3.withAttributeValueList(new AttributeValue().withS(category));
scanFilter.put("category", condition3);
}
// String queueUrl = SQS.getQueueUrl(new GetQueueUrlRequest(SQS_QUEUE_NAME)).getQueueUrl();
String tableName = DYNAMODB_TABLE_NAME;
ScanRequest scanRequest = new ScanRequest(tableName).withScanFilter(scanFilter);
ScanResult scanResult = DYNAMODB.scan(scanRequest);
int size = scanResult.getItems().size();
ArrayList<HashMap<String, String>> tweets = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < size; i++) {
// Get latitude, longitude, content, username, created (long), category, sentiment
String categorydb = "no category";
String sentiment = "no sentiment";
if (scanResult.getItems().get(i).get("category") != null) {
categorydb = scanResult.getItems().get(i).get("category").getS();
sentiment = scanResult.getItems().get(i).get("sentiment").getS();
String lat = scanResult.getItems().get(i).get("geoLat").getN();
String lng = scanResult.getItems().get(i).get("geoLng").getN();
String content = scanResult.getItems().get(i).get("content").getS();
String username = scanResult.getItems().get(i).get("username").getS();
String created = scanResult.getItems().get(i).get("createdLong").getN();
String createdDate = scanResult.getItems().get(i).get("createdDate").getS();
// Format date.
DateFormat fromFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
DateFormat toFormat = new SimpleDateFormat("MMM dd · k:mm z");
Date date;
String createdstr;
try {
date = fromFormat.parse(createdDate);
createdstr = toFormat.format(date);
} catch (ParseException e) {
createdstr = createdDate;
}
// Create tweet hash.
HashMap<String, String> tweet = new HashMap<String, String>();
tweet.put("lat", lat);
tweet.put("lng", lng);
tweet.put("content", content);
tweet.put("username", username);
tweet.put("category", categorydb);
tweet.put("sentiment", sentiment);
tweet.put("created", created);
tweet.put("createdstr", createdstr);
// Order tweet by time created. Most recent at the top of the list.
int position = 0;
while (position < tweets.size()
&& Long.parseLong(tweets.get(position).get("created")) > Long.parseLong(created)) {
position++;
}
tweets.add(position, tweet);
}
// else {
// Send tweet with blank category for sentimental processing
// String id = scanResult.getItems().get(i).get("id").getS();
// SQS.sendMessage(new SendMessageRequest(queueUrl, id));
// }
}
// Log result.
System.out.println("Successfully handled GET request.");
if (category != null) {
System.out.println("category:" + category);
}
System.out.println("size: " + tweets.size());
// Convert object to JSON format.
String json = new Gson().toJson(tweets);
response.setContentType("application/json");
response.setCharacterEncoding("UTF-8");
response.getWriter().write(json);
}