Java tutorial
package com.cloudhopper.smpp.simulator; /* * #%L * ch-smpp * %% * Copyright (C) 2009 - 2012 Cloudhopper by Twitter * %% * Licensed 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. * #L% */ import com.cloudhopper.smpp.pdu.Pdu; import com.cloudhopper.smpp.transcoder.PduTranscoder; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufUtil; import io.netty.channel.Channel; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ByteToMessageDecoder; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.concurrent.*; /** * Basically turns the event-driven handler into a "queued" handler by queuing * received PDUs and exceptions thrown. A calling thread can then "poll" for * these events. Also, the responses can be scheduled and queued ahead of time. * The next event that matches it will automatically write it back. * * @author joelauer (twitter: @jjlauer or <a href="http://twitter.com/jjlauer" target=window>http://twitter.com/jjlauer</a>) */ public class SmppSimulatorSessionHandler extends ByteToMessageDecoder { private static final Logger logger = LoggerFactory.getLogger(SmppSimulatorSessionHandler.class); private final Channel channel; private final PduTranscoder transcoder; private final BlockingQueue<Pdu> pduQueue; private final BlockingQueue<Throwable> exceptionQueue; private final BlockingDeque<Pdu> writePduQueue; private SmppSimulatorPduProcessor pduProcessor; public SmppSimulatorSessionHandler(Channel channel, PduTranscoder transcoder) { this.channel = channel; this.transcoder = transcoder; this.pduQueue = new LinkedBlockingQueue<Pdu>(); this.exceptionQueue = new LinkedBlockingQueue<Throwable>(); this.writePduQueue = new LinkedBlockingDeque<Pdu>(); } public SmppSimulatorPduProcessor getPduProcessor() { return this.pduProcessor; } public void setPduProcessor(SmppSimulatorPduProcessor pduProcessor) { this.pduProcessor = pduProcessor; } public Channel getChannel() { return this.channel; } public PduTranscoder getTranscoder() { return this.transcoder; } public BlockingQueue<Pdu> getPduQueue() { return this.pduQueue; } public void addPduToWriteOnNextPduReceived(Pdu pdu) { this.writePduQueue.add(pdu); } public Pdu pollNextPdu(long timeoutInMillis) throws InterruptedException { return this.pduQueue.poll(timeoutInMillis, TimeUnit.MILLISECONDS); } public BlockingQueue<Throwable> getThrowableQueue() { return this.exceptionQueue; } public Throwable pollNextThrowable(long timeoutInMillis) throws InterruptedException { return this.exceptionQueue.poll(timeoutInMillis, TimeUnit.MILLISECONDS); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { logger.info("Received new throwable on channel {}", channel.toString()); this.exceptionQueue.add(cause); } public void sendPdu(Pdu pdu) throws Exception { logger.info("Sending on channel {} PDU: {}", channel.toString(), pdu); ByteBuf writeBuffer = this.transcoder.encode(pdu); channel.writeAndFlush(writeBuffer).await(); } @Override protected void decode(ChannelHandlerContext ctx, ByteBuf buffer, List<Object> out) throws Exception { // ignore requests with zero bytes if (buffer.readableBytes() <= 0) { return; } // decode the buffer into a pdu Pdu pdu = transcoder.decode(buffer); // if the pdu was null, we don't have enough data yet if (pdu == null) { logger.info("Received data on channel {}, but not enough to parse PDU fully yet", channel.toString()); logger.info("Bytes in buffer: [{}]", ByteBufUtil.hexDump(buffer)); return; } logger.info("Decoded buffer on channel {} into PDU: {}", channel.toString(), pdu); // if we have a pdu procesor registered, let's see if it handles it boolean processed = false; if (this.pduProcessor != null) { processed = this.pduProcessor.process(this, channel, pdu); } if (processed) { logger.info("This PDU was processed by the registered PduProcessor"); } else { this.pduQueue.add(pdu); } // is there a PDU someone wants us to write in response? if (this.writePduQueue.size() > 0) { Pdu pduToWrite = this.writePduQueue.remove(); logger.info("Automatically writing back on channel {} the PDU: {}", channel.toString(), pduToWrite); ByteBuf writeBuffer = this.transcoder.encode(pduToWrite); channel.writeAndFlush(writeBuffer); } out.add(pdu); } }