Java tutorial
/* * Copyright 2013-2015 the original author or authors. * * 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.springframework.cloud.etcd.discovery; import com.netflix.client.config.IClientConfig; import com.netflix.loadbalancer.AbstractServerList; import mousio.etcd4j.EtcdClient; import mousio.etcd4j.responses.EtcdException; import mousio.etcd4j.responses.EtcdKeysResponse; import mousio.etcd4j.responses.EtcdKeysResponse.EtcdNode; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.util.ReflectionUtils; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.concurrent.TimeoutException; /** * @author Spencer Gibb */ public class EtcdServerList extends AbstractServerList<EtcdServer> { private static final Log log = LogFactory.getLog(EtcdServerList.class); private EtcdClient etcd; private EtcdDiscoveryProperties props; private String serviceId; public EtcdServerList() { } public EtcdServerList(EtcdClient etcd, EtcdDiscoveryProperties props, String serviceId) { this.etcd = etcd; this.props = props; this.serviceId = serviceId; } @Override public void initWithNiwsConfig(IClientConfig clientConfig) { this.serviceId = clientConfig.getClientName(); } @Override public List<EtcdServer> getInitialListOfServers() { return getServers(); } @Override public List<EtcdServer> getUpdatedListOfServers() { return getServers(); } private List<EtcdServer> getServers() { List<EtcdServer> servers = null; try { if (etcd == null) { return Collections.emptyList(); } EtcdKeysResponse response = etcd.getDir(props.getDiscoveryPrefix() + "/" + serviceId).send().get(); if (response.node.nodes == null || response.node.nodes.isEmpty()) { return Collections.emptyList(); } servers = new ArrayList<>(); for (EtcdNode node : response.node.nodes) { String[] appInfo = getAppInfo(node.key); String[] strings = node.value.split(":"); EtcdServer server = new EtcdServer(appInfo[0], appInfo[1], strings[0], strings[1]); servers.add(server); } } catch (IOException | TimeoutException | EtcdException e) { ReflectionUtils.rethrowRuntimeException(e); } return servers; } private String[] getAppInfo(String key) { String serviceNameId = key.replace(props.getDiscoveryPrefix(), ""); return serviceNameId.substring(1).split("/"); } }