你敢信？就是這個Netty的網路框架差點把我整瘋了，哭jj
阿新 • • 發佈：2020-12-07
不知道大家對下面的這個圖示眼熟不
對，這就是netty，最近差點整瘋了我的一個網路框架，下方是官網對他的描述，感興趣大家可以去官網看一下，這不是今天的重點，接著往下看：
為啥說這玩意快把我整瘋了啊，哎，好奇害死貓啊，我這人是對網路一竅不通，所以網路的東西我一般是不去觸碰的，但是，最近公司的人以及各大論壇裡面，netty這個技術真的是如日中天，我身邊的朋友去面試的回來也說這個技術問的有點多啊，我好奇心作怪就想去試一下，然後在網上查找了很多資料和程式碼實現，我就覺得沒啥，於是自己搭建了一下玩玩，比方說下面我要跟大家說的這個重點：netty+springboot實現 長連線 - 心跳 - 自動重連 - 通訊
然後出問題了，我作為程式設計師的執拗，不能有bug，這就出問題了，我們先來看一下網上的原始碼
個人公眾號：Java架構師聯盟
package com.gzky.study; import com.gzky.study.netty.MsgPckDecode; import com.gzky.study.netty.MsgPckEncode; import io.netty.bootstrap.Bootstrap; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioSocketChannel; import io.netty.handler.timeout.IdleStateHandler; import java.util.Scanner; /** * @author biws * @date 2020/11/20 **/ public class TestFor { private static NioEventLoopGroup worker = new NioEventLoopGroup(); private static Channel channel; private static Bootstrap bootstrap; boolean flag = true; public static void main(String[] args) { for (int i = 0; i < 30; i++) { long start = System.currentTimeMillis(); Scanner sc= new Scanner(System.in); long end = System.currentTimeMillis(); long l1 = end - start; long start2 = System.currentTimeMillis(); start(); long end2 = System.currentTimeMillis(); long l2 = end2 - start2; if (l1 > l2) { System.out.println("Scanner大，false"); } else { System.out.println("true--------------"); } } } private static void start() { bootstrap = new Bootstrap(); bootstrap.group(worker) .channel(NioSocketChannel.class) .option(ChannelOption.TCP_NODELAY, true) .handler(new ChannelInitializer<Channel>() { @Override protected void initChannel(Channel ch) throws Exception { // TODO Auto-generated method stub ChannelPipeline pipeline = ch.pipeline(); pipeline.addLast(new IdleStateHandler(3, 3, 5)); pipeline.addLast(new MsgPckDecode()); pipeline.addLast(new MsgPckEncode()); } }); doConnect(); } protected static void doConnect() { if (channel != null && channel.isActive()) { return; } ChannelFuture connect = bootstrap.connect("127.0.0.1", 8089); //實現監聽通道連線的方法 connect.addListener(new ChannelFutureListener() { @Override public void operationComplete(ChannelFuture channelFuture) throws Exception { if (channelFuture.isSuccess()) { channel = channelFuture.channel(); System.out.println("連線成功"); } } }); } }
好了，到這裡，沒問題，成功實現，我就覺得這也沒啥啊，這不是挺簡單的嘛，難道說他們是在面試的時候問道底層原始碼啊，這玩意整不了 啊，可能這就是命啊，我就沒關，讓他執行著，喝口飲料休息一下，沒想到突然就報錯了，然後又好了，emmmm，這不是自己給自己找事啊
通過測試，模擬30次大約有3次失敗的樣子，回看原始碼，其實程式碼中存在的矛盾不難發現，就是Scanner和Channel誰的建立時間更短。可能在他的電腦上沒有什麼問題，但是在我這裡就不行，感覺更像是在賭博，看你運氣怎麼樣，這樣那行啊，理工科的男孩子怎麼能靠賭博呢？
但是，咋整，我就在這一塊就是一個渣渣啊，沒辦法，最後還是求助了公司的大神，幸好程式碼量不是特別大，抽了個週末的下午，俺倆一起在原有的程式碼基礎上對客戶端進行可以定程度的改造，現在所有的功能都已經實現，下面附上改進後的程式碼，有需要的朋友可以自己動手實現一下
還是建議實現一下，畢竟可能我這裡可以了，但是在你的pc端又會有其他的而不一樣的問題，當然了，要是有云伺服器測試一下更 不錯
一、pom檔案
<!-- 解碼and編碼器 -->
<!-- https://mvnrepository.com/artifact/org.msgpack/msgpack -->
<dependency>
<groupId>org.msgpack</groupId>
<artifactId>msgpack</artifactId>
<version>0.6.12</version>
</dependency>
<!-- 引入netty依賴 -->
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.6.Final</version>
</dependency>
二、配置項
package com.gzky.study.netty;
/**
* 配置項
*
*
* @author biws
* @date 2020/11/20
**/
public interface TypeData {
//客戶端程式碼
byte PING = 1;
//服務端程式碼
byte PONG = 2;
//顧客
byte CUSTOMER = 3;
}
三、訊息型別分離器
package com.gzky.study.netty;
import org.msgpack.annotation.Message;
import java.io.Serializable;
/**
* 訊息型別分離器
*
*
* @author biws
* @date 2020/11/20
**/
@Message
public class Model implements Serializable {
private static final long serialVersionUID = 1L;
//型別
private int type;
//內容
private String body;
public int getType() {
return type;
}
public void setType(int type) {
this.type = type;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
@Override
public String toString() {
return "Model{" +
"type=" + type +
", body='" + body + '\'' +
'}';
}
}
四、編碼器
package com.gzky.study.netty;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import org.msgpack.MessagePack;
/**
* 編碼器
*
*
* @author biws
* @date 2020/11/20
**/
public class MsgPckEncode extends MessageToByteEncoder<Object> {
@Override
protected void encode(ChannelHandlerContext ctx, Object msg, ByteBuf buf)
throws Exception {
// TODO Auto-generated method stub
MessagePack pack = new MessagePack();
byte[] write = pack.write(msg);
buf.writeBytes(write);
}
}
五、解碼器
package com.gzky.study.netty;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;
import org.msgpack.MessagePack;
import java.util.List;
/**
* 解碼器
*
*
* @author biws
* @date 2020/11/20
**/
public class MsgPckDecode extends MessageToMessageDecoder<ByteBuf> {
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf msg,
List<Object> out) throws Exception {
final byte[] array;
final int length = msg.readableBytes();
array = new byte[length];
msg.getBytes(msg.readerIndex(), array, 0, length);
MessagePack pack = new MessagePack();
out.add(pack.read(array, Model.class));
}
}
六、公用控制器
package com.gzky.study.netty;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.timeout.IdleStateEvent;
/**
* 公用控制器
*
* @author biws
* @date 2020/11/20
**/
public abstract class Middleware extends ChannelInboundHandlerAdapter {
protected String name;
//記錄次數
private int heartbeatCount = 0;
//獲取server and client 傳入的值
public Middleware(String name) {
this.name = name;
}
/**
*繼承ChannelInboundHandlerAdapter實現了channelRead就會監聽到通道里面的訊息
*/
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
Model m = (Model) msg;
int type = m.getType();
switch (type) {
case 1:
sendPongMsg(ctx);
break;
case 2:
System.out.println(name + " get pong msg from" + ctx.channel().remoteAddress());
break;
case 3:
handlerData(ctx,msg);
break;
default:
break;
}
}
protected abstract void handlerData(ChannelHandlerContext ctx,Object msg);
protected void sendPingMsg(ChannelHandlerContext ctx){
Model model = new Model();
model.setType(TypeData.PING);
ctx.channel().writeAndFlush(model);
heartbeatCount++;
System.out.println(name + " send ping msg to " + ctx.channel().remoteAddress() + "count :" + heartbeatCount);
}
private void sendPongMsg(ChannelHandlerContext ctx) {
Model model = new Model();
model.setType(TypeData.PONG);
ctx.channel().writeAndFlush(model);
heartbeatCount++;
System.out.println(name +" send pong msg to "+ctx.channel().remoteAddress() +" , count :" + heartbeatCount);
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt)
throws Exception {
IdleStateEvent stateEvent = (IdleStateEvent) evt;
switch (stateEvent.state()) {
case READER_IDLE:
handlerReaderIdle(ctx);
break;
case WRITER_IDLE:
handlerWriterIdle(ctx);
break;
case ALL_IDLE:
handlerAllIdle(ctx);
break;
default:
break;
}
}
protected void handlerAllIdle(ChannelHandlerContext ctx) {
System.err.println("---ALL_IDLE---");
}
protected void handlerWriterIdle(ChannelHandlerContext ctx) {
System.err.println("---WRITER_IDLE---");
}
protected void handlerReaderIdle(ChannelHandlerContext ctx) {
System.err.println("---READER_IDLE---");
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
// TODO Auto-generated method stub
System.err.println(" ---"+ctx.channel().remoteAddress() +"----- is action" );
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
// TODO Auto-generated method stub
System.err.println(" ---"+ctx.channel().remoteAddress() +"----- is inAction");
}
}
七、客戶端
package com.gzky.study.netty;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.timeout.IdleStateHandler;
import java.util.Scanner;
import java.util.concurrent.TimeUnit;
/**
* Client客戶端
*
* @author biws
* @date 2020/11/20
**/
public class Client {
private NioEventLoopGroup worker = new NioEventLoopGroup();
private Channel channel;
private Bootstrap bootstrap;
boolean flag = true;
public static void main(String[] args) {
Client client = new Client();
client.start();
client.sendData();
//通訊結束，關閉客戶端
client.close();
}
private void close() {
channel.close();
worker.shutdownGracefully();
}
private void start() {
bootstrap = new Bootstrap();
bootstrap.group(worker)
.channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer<Channel>() {
@Override
protected void initChannel(Channel ch) throws Exception {
// TODO Auto-generated method stub
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new IdleStateHandler(3, 3, 5));
pipeline.addLast(new MsgPckDecode());
pipeline.addLast(new MsgPckEncode());
pipeline.addLast(new Client3Handler(Client.this));
}
});
doConnect();
}
/**
* 連線服務端 and 重連
*/
protected void doConnect() {
if (channel != null && channel.isActive()) {
return;
}
ChannelFuture connect = bootstrap.connect("127.0.0.1", 8089);
//實現監聽通道連線的方法
connect.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture channelFuture) throws Exception {
if (channelFuture.isSuccess()) {
channel = channelFuture.channel();
System.out.println("連線成功");
} else {
if (flag) {
System.out.println("每隔2s重連....");
channelFuture.channel().eventLoop().schedule(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
doConnect();
}
}, 2, TimeUnit.SECONDS);
}
}
}
});
}
/**
* 向服務端傳送訊息
*/
private void sendData() {
//建立連線成功之前停在這裡等待
while (channel == null || !channel.isActive()) {
System.out.println("等待連線···");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("連線成功等待輸入：");
flag = true;
Scanner sc = new Scanner(System.in);
while (flag) {
String nextLine = sc.nextLine();
if ("end".equalsIgnoreCase(nextLine)) {
flag = false;
}
Model model = new Model();
model.setType(TypeData.CUSTOMER);
model.setBody(nextLine);
channel.writeAndFlush(model);
}
}
}
八、客戶端控制器
package com.gzky.study.netty;
import io.netty.channel.ChannelHandlerContext;
/**
* 客戶端控制器
*
* @author biws
* @date 2020/11/20
**/
public class Client3Handler extends Middleware {
private Client client;
public Client3Handler(Client client) {
super("client");
this.client = client;
}
@Override
protected void handlerData(ChannelHandlerContext ctx, Object msg) {
// TODO Auto-generated method stub
Model model = (Model) msg;
System.out.println("client 收到資料： " + model.toString());
}
@Override
protected void handlerAllIdle(ChannelHandlerContext ctx) {
// TODO Auto-generated method stub
super.handlerAllIdle(ctx);
sendPingMsg(ctx);
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
// TODO Auto-generated method stub
super.channelInactive(ctx);
client.doConnect();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
System.out.println(name + "exception :"+ cause.toString());
}
}
九、服務端
package com.gzky.study.netty;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.timeout.IdleStateHandler;
/**
* 服務端
*
* @author biws
* @date 2020/11/20
**/
public class Server {
public static void main(String[] args) {
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup(4);
try {
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.localAddress(8089)
.childHandler(new ChannelInitializer<Channel>() {
@Override
protected void initChannel(Channel ch) throws Exception {
// TODO Auto-generated method stub
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new IdleStateHandler(10,3,10));
pipeline.addLast(new MsgPckDecode());
pipeline.addLast(new MsgPckEncode());
pipeline.addLast(new Server3Handler());
}
});
System.out.println("start server 8089 --");
ChannelFuture sync = serverBootstrap.bind().sync();
sync.channel().closeFuture().sync();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
//優雅的關閉資源
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
十、服務端控制器
package com.gzky.study.netty;
import io.netty.channel.ChannelHandlerContext;
/**
* 服務端控制器
*
* @author biws
* @date 2020/11/20
**/
public class Server3Handler extends Middleware {
public Server3Handler() {
super("server");
// TODO Auto-generated constructor stub
}
@Override
protected void handlerData(ChannelHandlerContext ctx, Object msg) {
// TODO Auto-generated method stub
Model model = (Model) msg;
System.out.println("server 接收資料 ： " + model.toString());
model.setType(TypeData.CUSTOMER);
model.setBody("client你好，server已接收到資料："+model.getBody());
ctx.channel().writeAndFlush(model);
System.out.println("server 傳送資料： " + model.toString());
}
@Override
protected void handlerReaderIdle(ChannelHandlerContext ctx) {
// TODO Auto-generated method stub
super.handlerReaderIdle(ctx);
System.err.println(" ---- client "+ ctx.channel().remoteAddress().toString() + " reader timeOut, --- close it");
ctx.close();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
System.err.println( name +" exception" + cause.toString());
}
}
十一、測試
1、啟動服務端
2、啟動客戶端
3、客戶端發訊息
在客戶端控制檯輸入：
服務端控制檯就可以收到hello，並且回信。
好了，到這裡，netty - springboot - 長連線 - 心跳 - 自動重連 - 通訊就完成了，不知道你實現了沒有，建議你可以先收藏，等有時間了自己實現一下，尤其是剛接觸的，覺得寫得還不錯的，可以轉發一下，讓更多人看見，謝謝
新的技術學習必定是充滿BUG的，但是，解決了就是一片光明，這樣一點點的改BUG中，剩下的就是你成長的路徑