Java tutorial
/** * Copyright (C) 2015 Zalando SE (http://tech.zalando.com) * * 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 org.zalando.baigan.etcd.service; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.datatype.guava.GuavaModule; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.zalando.baigan.etcd.model.KeyResultNode; import javax.annotation.Nonnull; import java.io.IOException; import java.net.URL; import java.util.Optional; /** * @author mchand */ public final class EtcdClient { private final Logger LOG = LoggerFactory.getLogger(EtcdClient.class); private final ObjectMapper mapper = new ObjectMapper().registerModule(new GuavaModule()); private final String etcdUrl; public EtcdClient(final String url) { etcdUrl = url; } public final Optional<String> get(@Nonnull final String key) { try { final URL url = new URL(etcdUrl + key); final KeyResultNode resultNode = mapper.readValue(url, KeyResultNode.class); final String response = resultNode.getNode().getValue(); return Optional.ofNullable(response); } catch (IOException e) { LOG.warn("There was an exception trying to get key: " + key, e); } catch (NullPointerException npe) { LOG.warn("There was an exception trying to get key: " + key); } return Optional.empty(); } }