Java tutorial
/* * Copyright 2015 Rackspace * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.rackspacecloud.blueflood.inputs.handlers; import com.codahale.metrics.Timer; import com.rackspacecloud.blueflood.exceptions.InvalidDataException; import com.rackspacecloud.blueflood.http.DefaultHandler; import com.rackspacecloud.blueflood.http.HttpRequestHandler; import com.rackspacecloud.blueflood.io.EventsIO; import com.rackspacecloud.blueflood.outputs.formats.ErrorResponse; import com.rackspacecloud.blueflood.types.Event; import com.rackspacecloud.blueflood.utils.Metrics; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.http.FullHttpRequest; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.util.CharsetUtil; import org.codehaus.jackson.JsonParseException; import org.codehaus.jackson.map.JsonMappingException; import org.codehaus.jackson.map.ObjectMapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.validation.ConstraintViolation; import javax.validation.Validation; import javax.validation.Validator; import javax.validation.ValidatorFactory; import java.util.*; public class HttpEventsIngestionHandler implements HttpRequestHandler { private static final Logger log = LoggerFactory.getLogger(HttpEventsIngestionHandler.class); private EventsIO searchIO; private final com.codahale.metrics.Timer httpEventsIngestTimer = Metrics.timer(HttpEventsIngestionHandler.class, "Handle HTTP request for ingesting events"); private static final ValidatorFactory factory = Validation.buildDefaultValidatorFactory(); protected static final Validator validator = factory.getValidator(); public HttpEventsIngestionHandler(EventsIO searchIO) { this.searchIO = searchIO; } @Override public void handle(ChannelHandlerContext ctx, FullHttpRequest request) { final String tenantId = request.headers().get(Event.FieldLabels.tenantId.name()); String response = ""; ObjectMapper objectMapper = new ObjectMapper(); final Timer.Context httpEventsIngestTimerContext = httpEventsIngestTimer.time(); try { String body = request.content().toString(0, request.content().writerIndex(), CharsetUtil.UTF_8); Event event = objectMapper.readValue(body, Event.class); // To verify if the request has multiple elements. If some one sends request with multiple root elements, // parser does not throw any validation exceptions. We are checking it manually here. Iterator<Event> iterator = objectMapper.reader(Event.class).readValues(body); if (iterator.hasNext()) { iterator.next(); if (iterator.hasNext()) { //has more than one element throw new InvalidDataException("Only one event is allowed per request"); } } Set<ConstraintViolation<Event>> constraintViolations = validator.validate(event); List<ErrorResponse.ErrorData> validationErrors = new ArrayList<ErrorResponse.ErrorData>(); for (ConstraintViolation<Event> constraintViolation : constraintViolations) { validationErrors.add( new ErrorResponse.ErrorData(tenantId, "", constraintViolation.getPropertyPath().toString(), constraintViolation.getMessage(), event.getWhen())); } if (!validationErrors.isEmpty()) { DefaultHandler.sendErrorResponse(ctx, request, validationErrors, HttpResponseStatus.BAD_REQUEST); return; } searchIO.insert(tenantId, Arrays.asList(event.toMap())); DefaultHandler.sendResponse(ctx, request, response, HttpResponseStatus.OK); } catch (JsonMappingException e) { log.debug(String.format("Exception %s", e.toString())); response = String.format("Invalid Data: %s", e.getMessage()); DefaultHandler.sendErrorResponse(ctx, request, response, HttpResponseStatus.BAD_REQUEST); } catch (JsonParseException e) { log.debug(String.format("Exception %s", e.toString())); response = String.format("Invalid Data: %s", e.getMessage()); DefaultHandler.sendErrorResponse(ctx, request, response, HttpResponseStatus.BAD_REQUEST); } catch (InvalidDataException e) { log.debug(String.format("Exception %s", e.toString())); response = String.format("Invalid Data: %s", e.getMessage()); DefaultHandler.sendErrorResponse(ctx, request, response, HttpResponseStatus.BAD_REQUEST); } catch (Exception e) { log.error(String.format("Exception %s", e.toString())); response = String.format("Error: %s", e.getMessage()); DefaultHandler.sendErrorResponse(ctx, request, response, HttpResponseStatus.INTERNAL_SERVER_ERROR); } finally { httpEventsIngestTimerContext.stop(); } } }