Java tutorial
/* * Copyright Jerry Xiong, BOSSCS * * The Project 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.bosscs.spark.commons.extractor.server; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import org.apache.log4j.Logger; import org.apache.spark.Partition; import com.bosscs.spark.commons.config.ExtractorConfig; import com.bosscs.spark.commons.entity.Cells; import com.bosscs.spark.commons.exception.HadoopInstantiationException; import com.bosscs.spark.commons.extractor.actions.Action; import com.bosscs.spark.commons.extractor.actions.GetPartitionsAction; import com.bosscs.spark.commons.extractor.actions.HasNextAction; import com.bosscs.spark.commons.extractor.actions.InitIteratorAction; import com.bosscs.spark.commons.extractor.actions.InitSaveAction; import com.bosscs.spark.commons.extractor.actions.NextAction; import com.bosscs.spark.commons.extractor.actions.SaveAction; import com.bosscs.spark.commons.extractor.response.CloseResponse; import com.bosscs.spark.commons.extractor.response.GetPartitionsResponse; import com.bosscs.spark.commons.extractor.response.HasNextResponse; import com.bosscs.spark.commons.extractor.response.InitIteratorResponse; import com.bosscs.spark.commons.extractor.response.InitSaveResponse; import com.bosscs.spark.commons.extractor.response.NextResponse; import com.bosscs.spark.commons.extractor.response.Response; import com.bosscs.spark.commons.extractor.response.SaveResponse; import com.bosscs.spark.commons.rdd.IExtractor; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import java.util.logging.Level; public class ExtractorServerHandler<T> extends SimpleChannelInboundHandler<Action> { private static final Logger LOG = Logger.getLogger(ExtractorServerHandler.class); private IExtractor<T, ExtractorConfig<T>> extractor; @Override public void channelRead0(ChannelHandlerContext ctx, Action action) throws Exception { Response response = null; switch (action.getType()) { case GET_PARTITIONS: GetPartitionsAction<T> partitionsAction = (GetPartitionsAction<T>) action; response = new GetPartitionsResponse(this.getPartitions(partitionsAction)); break; case CLOSE: this.close(); response = new CloseResponse(); break; case HAS_NEXT: HasNextAction<T> hasNextAction = (HasNextAction<T>) action; response = new HasNextResponse(this.hastNext(hasNextAction)); break; case NEXT: NextAction<T> nextAction = (NextAction<T>) action; response = new NextResponse<T>(this.next(nextAction)); break; case INIT_ITERATOR: InitIteratorAction<T> initIteratorAction = (InitIteratorAction<T>) action; this.initIterator(initIteratorAction); response = new InitIteratorResponse(); break; case SAVE: SaveAction<T> SaveAction = (SaveAction<T>) action; this.save(SaveAction); response = new SaveResponse(); break; case INIT_SAVE: InitSaveAction<T> initSave = (InitSaveAction<T>) action; this.initSave(initSave); response = new InitSaveResponse(); break; default: break; } ctx.write(response); } @Override public void channelReadComplete(ChannelHandlerContext ctx) { ctx.flush(); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { LOG.error(cause.getMessage()); ctx.close(); } protected boolean hastNext(HasNextAction hasNextAction) { return extractor.hasNext(); } protected T next(NextAction<T> nextAction) { return extractor.next(); } protected void close() { extractor.close(); return; } protected void initIterator(InitIteratorAction<T> initIteratorAction) { if (extractor == null) { this.initExtractor(initIteratorAction.getConfig()); } extractor.initIterator(initIteratorAction.getPartition(), initIteratorAction.getConfig()); return; } protected Partition[] getPartitions(GetPartitionsAction<T> getPartitionsAction) { if (extractor == null) { this.initExtractor(getPartitionsAction.getConfig()); } return extractor.getPartitions(getPartitionsAction.getConfig()); } /** * @param config */ @SuppressWarnings("unchecked") private void initExtractor(ExtractorConfig<T> config) { try { Class<T> rdd = config.getExtractorImplClass(); if (rdd == null) { rdd = (Class<T>) Class.forName(config.getExtractorImplClassName()); } Constructor<T> c = null; if (config.getEntityClass().isAssignableFrom(Cells.class)) { c = rdd.getConstructor(); this.extractor = (IExtractor<T, ExtractorConfig<T>>) c.newInstance(); } else { c = rdd.getConstructor(Class.class); this.extractor = (IExtractor<T, ExtractorConfig<T>>) c.newInstance(config.getEntityClass()); } } catch (ClassNotFoundException | HadoopInstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | NoSuchMethodException | SecurityException e) { LOG.error("Impossible to make an extractor instance, check classpath " + e.getMessage()); throw new HadoopInstantiationException( "Impossible to make an extractor instance, check classpath " + e.getMessage()); } catch (java.lang.InstantiationException ex) { java.util.logging.Logger.getLogger(ExtractorServerHandler.class.getName()).log(Level.SEVERE, null, ex); } } protected void initSave(InitSaveAction<T> initSaveAction) { if (extractor == null) { this.initExtractor(initSaveAction.getConfig()); } extractor.initSave(initSaveAction.getConfig(), initSaveAction.getFirst(), initSaveAction.getQueryBuilder()); return; } protected void save(SaveAction<T> saveAction) { extractor.saveRDD(saveAction.getRecord()); return; } }