Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.alibaba.jstorm.ui; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.util.Map; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.yaml.snakeyaml.Yaml; import backtype.storm.Config; import backtype.storm.utils.NimbusClient; import backtype.storm.utils.Utils; import com.alibaba.jstorm.utils.ExpiredCallback; import com.alibaba.jstorm.utils.TimeCacheMap; public class NimbusClientManager { private static Logger LOG = LoggerFactory.getLogger(NimbusClientManager.class); public static String DEFAULT = "default"; protected static TimeCacheMap<String, NimbusClient> clientManager; static { clientManager = new TimeCacheMap<String, NimbusClient>(3600, new ExpiredCallback<String, NimbusClient>() { @Override public void expire(String key, NimbusClient val) { // TODO Auto-generated method stub LOG.info("Close connection of " + key); val.close(); } }); } public static NimbusClient getNimbusClient(String clusterName) throws Exception { Map conf = UIUtils.readUiConfig(); if (DEFAULT.equals(clusterName)) { // do nothing } else if (StringUtils.isBlank(clusterName) == false) { UIUtils.getClusterInfoByName(conf, clusterName); } return NimbusClient.getConfiguredClient(conf); } public static NimbusClient getNimbusClient(Map<String, String> parameterMap) throws Exception { String clusterName = parameterMap.get(UIDef.CLUSTER); if (StringUtils.isBlank(clusterName) == true) { clusterName = DEFAULT; } NimbusClient client = clientManager.get(clusterName); if (client != null) { try { client.getClient().getVersion(); } catch (Exception e) { LOG.info("Nimbus has been restarted, it begin to reconnect"); client = null; } } if (client != null) { return client; } client = getNimbusClient(clusterName); clientManager.put(clusterName, client); return client; } public static void removeClient(Map<String, String> parameterMap) { String clusterName = parameterMap.get(UIDef.CLUSTER); if (StringUtils.isBlank(clusterName) == true) { clusterName = DEFAULT; } NimbusClient client = (NimbusClient) clientManager.remove(clusterName); if (client != null) { client.close(); } } }