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.client.codecs; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.ObjectInput; import java.io.ObjectInputStream; import java.util.List; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.bosscs.spark.commons.extractor.actions.Action; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ByteToMessageDecoder; public class ActionDecoder extends ByteToMessageDecoder { private static final Logger LOG = LoggerFactory.getLogger(ActionDecoder.class); protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) { // Wait until the length prefix is available. if (in.readableBytes() < 5) { return; } // Wait until the whole data is available. int dataLength = in.readInt(); if (in.readableBytes() < dataLength) { in.resetReaderIndex(); return; } // Convert the received data into a new BigInteger. byte[] decoded = new byte[dataLength]; in.readBytes(decoded); ByteArrayInputStream bis = new ByteArrayInputStream(decoded); ObjectInput inObj = null; Action action = null; try { inObj = new ObjectInputStream(bis); action = (Action) inObj.readObject(); } catch (IOException | ClassNotFoundException e) { LOG.error(e.getMessage()); } finally { try { bis.close(); } catch (IOException ex) { // ignore close exception } try { if (inObj != null) { inObj.close(); } } catch (IOException ex) { // ignore close exception } } out.add(action); } }