Java tutorial
/** * 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.seyren.core.service.notification; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.inject.Inject; import javax.inject.Named; import com.fasterxml.jackson.databind.ObjectMapper; import org.apache.commons.lang.StringUtils; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.utils.HttpClientUtils; import org.apache.http.entity.ContentType; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.util.EntityUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.seyren.core.domain.Alert; import com.seyren.core.domain.Check; import com.seyren.core.domain.Subscription; import com.seyren.core.domain.SubscriptionType; import com.seyren.core.exception.NotificationFailedException; import com.seyren.core.util.config.SeyrenConfig; @Named public class HttpNotificationService implements NotificationService { private static final Logger LOGGER = LoggerFactory.getLogger(HttpNotificationService.class); private static final ObjectMapper MAPPER = new ObjectMapper(); private final SeyrenConfig seyrenConfig; @Inject public HttpNotificationService(SeyrenConfig seyrenConfig) { this.seyrenConfig = seyrenConfig; } @Override public void sendNotification(Check check, Subscription subscription, List<Alert> alerts) throws NotificationFailedException { String httpUrl = StringUtils.trimToNull(subscription.getTarget()); if (httpUrl == null) { LOGGER.warn("URL needs to be set before sending notifications to HTTP"); return; } Map<String, Object> body = new HashMap<String, Object>(); body.put("seyrenUrl", seyrenConfig.getBaseUrl()); body.put("check", check); body.put("subscription", subscription); body.put("alerts", alerts); body.put("preview", getPreviewImage(check)); HttpClient client = HttpClientBuilder.create().useSystemProperties().build(); HttpPost post; if (StringUtils.isNotBlank(seyrenConfig.getHttpNotificationUrl())) { post = new HttpPost(seyrenConfig.getHttpNotificationUrl()); } else { post = new HttpPost(subscription.getTarget()); } try { HttpEntity entity = new StringEntity(MAPPER.writeValueAsString(body), ContentType.APPLICATION_JSON); post.setEntity(entity); HttpResponse response = client.execute(post); HttpEntity responseEntity = response.getEntity(); if (responseEntity != null) { LOGGER.info("Response : {} ", EntityUtils.toString(responseEntity)); } } catch (Exception e) { throw new NotificationFailedException("Failed to send notification to HTTP", e); } finally { post.releaseConnection(); HttpClientUtils.closeQuietly(client); } } @Override public boolean canHandle(SubscriptionType subscriptionType) { return subscriptionType == SubscriptionType.HTTP; } private String getPreviewImage(Check check) { return "<br /><img src=" + seyrenConfig.getGraphiteUrl() + "/render/?target=" + check.getTarget() + getTimeFromUntilString(new Date()) + "&target=alias(dashed(color(constantLine(" + check.getWarn().toString() + "),%22yellow%22)),%22warn%20level%22)&target=alias(dashed(color(constantLine(" + check.getError().toString() + "),%22red%22)),%22error%20level%22)&width=500&height=225></img>"; } private String getTimeFromUntilString(Date date) { Calendar cal = Calendar.getInstance(); SimpleDateFormat format = new SimpleDateFormat("HH:mm_yyyyMMdd"); cal.setTime(date); cal.add(Calendar.HOUR, -1); String from = format.format(cal.getTime()); cal.add(Calendar.HOUR, 1); String until = format.format(cal.getTime()); return "&from=" + until + "&until=" + from; } }