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.nutch.api.impl; import java.util.Collections; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.concurrent.atomic.AtomicInteger; import org.apache.commons.collections.MapUtils; import org.apache.commons.lang.StringUtils; import org.apache.hadoop.conf.Configuration; import org.apache.nutch.api.ConfManager; import org.apache.nutch.api.model.request.NutchConfig; import org.apache.nutch.api.resources.ConfigResource; import org.apache.nutch.util.NutchConfiguration; import com.google.common.collect.Maps; public class RAMConfManager implements ConfManager { private Map<String, Configuration> configurations = Maps.newConcurrentMap(); private AtomicInteger newConfigId = new AtomicInteger(); public RAMConfManager() { configurations.put(ConfigResource.DEFAULT, NutchConfiguration.create()); } public Set<String> list() { return configurations.keySet(); } public Configuration get(String confId) { if (confId == null) { return configurations.get(ConfigResource.DEFAULT); } return configurations.get(confId); } public Map<String, String> getAsMap(String confId) { Configuration configuration = configurations.get(confId); if (configuration == null) { return Collections.emptyMap(); } Iterator<Entry<String, String>> iterator = configuration.iterator(); Map<String, String> configMap = Maps.newTreeMap(); while (iterator.hasNext()) { Entry<String, String> entry = iterator.next(); configMap.put(entry.getKey(), entry.getValue()); } return configMap; } public void setProperty(String confId, String propName, String propValue) { if (!configurations.containsKey(confId)) { throw new IllegalArgumentException("Unknown configId '" + confId + "'"); } Configuration conf = configurations.get(confId); conf.set(propName, propValue); } public void delete(String confId) { configurations.remove(confId); } @Override public String create(NutchConfig nutchConfig) { if (StringUtils.isBlank(nutchConfig.getConfigId())) { nutchConfig.setConfigId(String.valueOf(newConfigId.incrementAndGet())); } if (!canCreate(nutchConfig)) { throw new IllegalArgumentException("Config already exists."); } createHadoopConfig(nutchConfig); return nutchConfig.getConfigId(); } private boolean canCreate(NutchConfig nutchConfig) { if (nutchConfig.isForce()) { return true; } if (!configurations.containsKey(nutchConfig.getConfigId())) { return true; } return false; } private void createHadoopConfig(NutchConfig nutchConfig) { Configuration conf = NutchConfiguration.create(); configurations.put(nutchConfig.getConfigId(), conf); if (MapUtils.isEmpty(nutchConfig.getParams())) { return; } for (Entry<String, String> e : nutchConfig.getParams().entrySet()) { conf.set(e.getKey(), e.getValue()); } } }