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 org.apache.eagle.topology.resolver.impl; import com.fasterxml.jackson.databind.ObjectMapper; import org.apache.commons.lang.StringUtils; import org.apache.eagle.app.utils.AppConstants; import org.apache.eagle.app.utils.connection.InputStreamUtils; import org.apache.eagle.topology.TopologyCheckAppConfig; import org.apache.eagle.topology.resolver.TopologyRackResolver; import org.apache.eagle.topology.resolver.model.Node; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.InputStream; /** * resolve rack by ClusterNode API. * https://hadoop.apache.org/docs/r2.6.0/hadoop-yarn/hadoop-yarn-site/ResourceManagerRest.html */ public class ClusterNodeAPITopologyRackResolver implements TopologyRackResolver { private static final Logger LOG = LoggerFactory.getLogger(ClusterNodeAPITopologyRackResolver.class); private static final String DEFAULT_RACK_NAME = "default-rack"; private String activeApiUrl = ""; private String hostPort = "8041";//TODO configurable private static final ObjectMapper OBJ_MAPPER = new ObjectMapper(); @Override public void prepare(TopologyCheckAppConfig config) { this.activeApiUrl = config.getConfig().getString("topology.resolverAPIUrl"); } @Override public String resolve(String hostname) { String nodeid = hostname + ":" + hostPort; String requestUrl = activeApiUrl + "/" + nodeid; String rack = DEFAULT_RACK_NAME; InputStream is = null; try { is = InputStreamUtils.getInputStream(requestUrl, null, AppConstants.CompressionType.NONE); LOG.info("resolve rack by api url {}", requestUrl); Node node = OBJ_MAPPER.readValue(is, Node.class); rack = StringUtils.removeStart(node.getNode().getRack(), "/"); } catch (Exception e) { LOG.warn("resolve rack by api url {} failed, {}", requestUrl, e); return rack; } finally { if (is != null) { try { is.close(); } catch (Exception e) { LOG.warn("{}", e); } } } return rack; } }