Java tutorial
/* Copyright 2013-2014 SpruceHill.io GmbH 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 io.sprucehill.mandrill.service; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import io.sprucehill.mandrill.data.request.AbstractPayload; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.PoolingClientConnectionManager; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.annotation.PostConstruct; import java.io.IOException; /** * @author Michael Duergner <michael@sprucehill.io> */ public abstract class AbstractService { final Logger logger = LoggerFactory.getLogger(getClass()); String baseUrl = "https://mandrillapp.com/api/1.0"; HttpClient httpClient; ObjectMapper objectMapper; String key; /** * * @param baseUrl */ public void setBaseUrl(String baseUrl) { this.baseUrl = baseUrl; } /** * * @param httpClient */ public void setHttpClient(HttpClient httpClient) { this.httpClient = httpClient; } /** * * @param objectMapper */ public void setObjectMapper(ObjectMapper objectMapper) { this.objectMapper = objectMapper; } /** * * @param key */ public void setKey(String key) { this.key = key; } @PostConstruct public final void postConstruct() { onPostConstruct(); } void onPostConstruct() { if (null == httpClient) { httpClient = new DefaultHttpClient(new PoolingClientConnectionManager()); } if (null == objectMapper) { objectMapper = new ObjectMapper(); } } <T extends AbstractPayload.Init<T, U>, U extends AbstractPayload> void integrateDefaultValues( AbstractPayload.Init<T, U> payloadBuilder) { if (!payloadBuilder.hasKey() && null != key && !key.isEmpty()) { payloadBuilder.withKey(key); } } <T, E extends Error> T send(final AbstractPayload payload, TypeReference<T> responseClass, Class<E> errorClass) throws E, IOException { try { HttpPost request = new HttpPost(baseUrl + payload.getPath()); String body = objectMapper.writeValueAsString(payload); logger.info(body); request.setEntity(new StringEntity(body, "UTF-8")); HttpResponse response = httpClient.execute(request); if (200 == response.getStatusLine().getStatusCode()) { T result = objectMapper.readValue(response.getEntity().getContent(), responseClass); return result; } else { E error = objectMapper.readValue(response.getEntity().getContent(), errorClass); logger.debug("Got error {} while calling {}.", error.toString(), payload.getPath()); throw error; } } catch (IOException e) { logger.debug("Got {} while calling {}.", e.getClass().getSimpleName(), payload.getPath()); throw e; } } }