一、执行器项目

1、执行器组件配置类

@Configuration
public class XxlJobConfig {
    private Logger logger = LoggerFactory.getLogger(XxlJobConfig.class);
    @Value("${xxl.job.admin.addresses}")
    private String adminAddresses;
    @Value("${xxl.job.executor.appname}")
    private String appName;
    @Value("${xxl.job.executor.ip}")
    private String ip;
    @Value("${xxl.job.executor.port}")
    private int port;
    @Value("${xxl.job.accessToken}")
    private String accessToken;
    @Value("${xxl.job.executor.logpath}")
    private String logPath;
    @Value("${xxl.job.executor.logretentiondays}")
    private int logRetentionDays;
    @Bean
    public XxlJobSpringExecutor xxlJobExecutor() {
        logger.info(">>>>>>>>>>> xxl-job config init.");
        XxlJobSpringExecutor xxlJobSpringExecutor = new XxlJobSpringExecutor();
        xxlJobSpringExecutor.setAdminAddresses(adminAddresses);
        xxlJobSpringExecutor.setAppName(appName);
        xxlJobSpringExecutor.setIp(ip);
        xxlJobSpringExecutor.setPort(port);
        xxlJobSpringExecutor.setAccessToken(accessToken);
        xxlJobSpringExecutor.setLogPath(logPath);
        xxlJobSpringExecutor.setLogRetentionDays(logRetentionDays);
        return xxlJobSpringExecutor;
    }
}

2、XxlJobSpringExecutor 类

InitializingBean接口：初始化后就会调用afterPropertiesSet()方法
ApplicationContextAware接口：有了获取applicationContext能务
DisposableBean接口：IOC销毁时 调用destory方法

3、查看XxlJobSpringExecutor 类的afterPropertiesSet()方法

@Override
public void afterPropertiesSet() throws Exception {
    //获取类上有@JobHandler注解的bean，
    //放到jobHandlerRepository变量map中
    initJobHandlerRepository(applicationContext);
    //将方法上有@XxlJob注解的方法，打包成MethodJobHandler类，加入到jobHandlerRepository变量map中
    initJobHandlerMethodRepository(applicationContext);
    //初始化GlueFactory=new SpringGlueFactory()
    GlueFactory.refreshInstance(1);
    super.start();
}

3.1、查看super.start();

public void start() throws Exception {
    // 初始化日志路径logpath
    XxlJobFileAppender.initLogPath(logPath);
    //初始化调度中心客户端对象 AdminBizClient
    //加入到List<AdminBiz> adminBizList变量中
    initAdminBizList(adminAddresses, accessToken);
    //启动日志清理线程，定时清理时间范围内的日志文件
    JobLogFileCleanThread.getInstance().start(logRetentionDays);
    //启动一个线程，消费callBackQueue队列，
    //遍历adminBizList调用adminBiz.callback(callbackParamList)方法
    TriggerCallbackThread.getInstance().start();
    //初始化监听服务
    port = port>0?port: NetUtil.findAvailablePort(9999);
    ip = (ip!=null&&ip.trim().length()>0)?ip: IpUtil.getIp();
    initRpcProvider(ip, port, appName, accessToken);
}

3.2、查看initRpcProvider(ip, port, appName, accessToken);方法

private void initRpcProvider(String ip, int port, String appName, String accessToken) throws Exception {
   // init, provider factory
    String address = IpUtil.getIpPort(ip, port);
    Map<String, String> serviceRegistryParam = new HashMap<String, String>();
    serviceRegistryParam.put("appName", appName);
    serviceRegistryParam.put("address", address);
    xxlRpcProviderFactory = new XxlRpcProviderFactory();
    xxlRpcProviderFactory.setServer(NettyHttpServer.class);
    xxlRpcProviderFactory.setSerializer(HessianSerializer.class);
    xxlRpcProviderFactory.setCorePoolSize(20);
    xxlRpcProviderFactory.setMaxPoolSize(200);
    xxlRpcProviderFactory.setIp(ip);
    xxlRpcProviderFactory.setPort(port);
    xxlRpcProviderFactory.setAccessToken(accessToken);
    xxlRpcProviderFactory.setServiceRegistry(ExecutorServiceRegistry.class);
    xxlRpcProviderFactory.setServiceRegistryParam(serviceRegistryParam);

    // add services，为个service是重点，
    //后面netty处理业务handler会获取这个service中的bean，
    //根据接收到的参数执行不同的方法
    xxlRpcProviderFactory.addService(ExecutorBiz.class.getName(), null, new ExecutorBizImpl());

    // start
    xxlRpcProviderFactory.start();
}

3.3、xxlRpcProviderFactory.start();方法

只列出核心代码

public void start() throws Exception {
    this.serializerInstance = (Serializer)this.serializer.newInstance();
    this.serviceAddress = IpUtil.getIpPort(this.ip, this.port);
    //实例化server对象，也就是NettyHttpServer对象
    this.serverInstance = (Server)this.server.newInstance();
    //设置NettyHttpServer的startedCallback方法
    this.serverInstance.setStartedCallback(new BaseCallback() {
        public void run() throws Exception {
            if (XxlRpcProviderFactory.this.serviceRegistry != null) {
                XxlRpcProviderFactory.this.serviceRegistryInstance = (ServiceRegistry)XxlRpcProviderFactory.this.serviceRegistry.newInstance();
                XxlRpcProviderFactory.this.serviceRegistryInstance.start(XxlRpcProviderFactory.this.serviceRegistryParam);
                if (XxlRpcProviderFactory.this.serviceData.size() > 0) {
                    XxlRpcProviderFactory.this.serviceRegistryInstance.registry(XxlRpcProviderFactory.this.serviceData.keySet(), XxlRpcProviderFactory.this.serviceAddress);
                }
            }

        }
    });
    //设置NettyHttpServer的StopedCallback方法
    this.serverInstance.setStopedCallback(new BaseCallback() {
        public void run() {
            if (XxlRpcProviderFactory.this.serviceRegistryInstance != null) {
                if (XxlRpcProviderFactory.this.serviceData.size() > 0) {
                    XxlRpcProviderFactory.this.serviceRegistryInstance.remove(XxlRpcProviderFactory.this.serviceData.keySet(), XxlRpcProviderFactory.this.serviceAddress);
                }

                XxlRpcProviderFactory.this.serviceRegistryInstance.stop();
                XxlRpcProviderFactory.this.serviceRegistryInstance = null;
            }

        }
    });
    //调用NettyHttpServer的start()方法
    this.serverInstance.start(this);
}

3.4、查看NettyHttpServer.start()方法

这个方法，启动了一个 线程，启动netty服务监听9999端口，将NettyHttpServerHandler加到管道，这个类会接收输入流，处理业务逻辑

public void start(final XxlRpcProviderFactory xxlRpcProviderFactory) throws Exception {
   this.thread = new Thread(new Runnable() {
     
       public void run() {
           final ThreadPoolExecutor serverHandlerPool = ThreadPoolUtil.makeServerThreadPool(NettyHttpServer.class.getSimpleName(), xxlRpcProviderFactory.getCorePoolSize(), xxlRpcProviderFactory.getMaxPoolSize());
           EventLoopGroup bossGroup = new NioEventLoopGroup();
           NioEventLoopGroup workerGroup = new NioEventLoopGroup();

           try {
               ServerBootstrap bootstrap = new ServerBootstrap();
               ((ServerBootstrap)bootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)).childHandler(new ChannelInitializer<SocketChannel>() {
                   public void initChannel(SocketChannel channel) throws Exception {
                       channel.pipeline().addLast(new ChannelHandler[]{new IdleStateHandler(0L, 0L, 90L, TimeUnit.SECONDS)}).addLast(new ChannelHandler[]{new HttpServerCodec()}).addLast(new ChannelHandler[]{new HttpObjectAggregator(5242880)}).addLast(new ChannelHandler[]{new NettyHttpServerHandler(xxlRpcProviderFactory, serverHandlerPool)});
                   }
               }).childOption(ChannelOption.SO_KEEPALIVE, true);
                 //启动了一个netty服务，监听xxlRpcProviderFactory.getPort()这个端口，也就是9999端口
               ChannelFuture future = bootstrap.bind(xxlRpcProviderFactory.getPort()).sync();
               NettyHttpServer.logger.info(">>>>>>>>>>> xxl-rpc remoting server start success, nettype = {}, port = {}", NettyHttpServer.class.getName(), xxlRpcProviderFactory.getPort());
               NettyHttpServer.this.onStarted();
               future.channel().closeFuture().sync();
           } catch (InterruptedException var18) {
               if (var18 instanceof InterruptedException) {
                   NettyHttpServer.logger.info(">>>>>>>>>>> xxl-rpc remoting server stop.");
               } else {
                   NettyHttpServer.logger.error(">>>>>>>>>>> xxl-rpc remoting server error.", var18);
               }
           } finally {
               try {
                   serverHandlerPool.shutdown();
               } catch (Exception var17) {
                   NettyHttpServer.logger.error(var17.getMessage(), var17);
               }

               try {
                   workerGroup.shutdownGracefully();
                   bossGroup.shutdownGracefully();
               } catch (Exception var16) {
                   NettyHttpServer.logger.error(var16.getMessage(), var16);
               }

           }

       }
   });
   this.thread.setDaemon(true);
   //启动线程
   this.thread.start();
}

3.5、NettyHttpServerHandler.channelRead0()方法

protected void channelRead0(final ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
    final byte[] requestBytes = ByteBufUtil.getBytes(msg.content());
    final String uri = msg.uri();
    final boolean keepAlive = HttpUtil.isKeepAlive(msg);
    //启动一个线程，提交给线程池执行
    this.serverHandlerPool.execute(new Runnable() {
        public void run() {
            NettyHttpServerHandler.this.process(ctx, uri, requestBytes, keepAlive);
        }
    });
}

NettyHttpServerHandler.this.process方法

private void process(ChannelHandlerContext ctx, String uri, byte[] requestBytes, boolean keepAlive) {
    String requestId = null;

    XxlRpcResponse xxlRpcResponse;
    byte[] responseBytes;
    try {
        if ("/services".equals(uri)) {
            StringBuffer stringBuffer = new StringBuffer("<ui>");
            Iterator var11 = this.xxlRpcProviderFactory.getServiceData().keySet().iterator();

            while(var11.hasNext()) {
                String serviceKey = (String)var11.next();
                stringBuffer.append("<li>").append(serviceKey).append(": ").append(this.xxlRpcProviderFactory.getServiceData().get(serviceKey)).append("</li>");
            }

            stringBuffer.append("</ui>");
            byte[] responseBytes = stringBuffer.toString().getBytes("UTF-8");
            this.writeResponse(ctx, keepAlive, responseBytes);
        } else {
            if (requestBytes.length == 0) {
                throw new XxlRpcException("xxl-rpc request data empty.");
            }

            XxlRpcRequest xxlRpcRequest = (XxlRpcRequest)this.xxlRpcProviderFactory.getSerializerInstance().deserialize(requestBytes, XxlRpcRequest.class);
            requestId = xxlRpcRequest.getRequestId();
            if ("BEAT_PING_PONG".equalsIgnoreCase(xxlRpcRequest.getRequestId())) {
                logger.debug(">>>>>>>>>>> xxl-rpc provider netty_http server read beat-ping.");
                return;
            }
            //主要看这个方法，invokeService，
            xxlRpcResponse = this.xxlRpcProviderFactory.invokeService(xxlRpcRequest);
            responseBytes = this.xxlRpcProviderFactory.getSerializerInstance().serialize(xxlRpcResponse);
            this.writeResponse(ctx, keepAlive, responseBytes);
        }
    } catch (Exception var9) {
        logger.error(var9.getMessage(), var9);
        xxlRpcResponse = new XxlRpcResponse();
        xxlRpcResponse.setRequestId(requestId);
        xxlRpcResponse.setErrorMsg(ThrowableUtil.toString(var9));
        responseBytes = this.xxlRpcProviderFactory.getSerializerInstance().serialize(xxlRpcResponse);
        this.writeResponse(ctx, keepAlive, responseBytes);
    }
}

3.6、invokeService

只列出核心代码

public XxlRpcResponse invokeService(XxlRpcRequest xxlRpcRequest) {
    XxlRpcResponse xxlRpcResponse = new XxlRpcResponse();
    xxlRpcResponse.setRequestId(xxlRpcRequest.getRequestId());
    //接收className和version
    String serviceKey = makeServiceKey(xxlRpcRequest.getClassName(), xxlRpcRequest.getVersion());
    //从serviceDate 根据key获取bean，这个serviceData对象是3.2中初始化的，会获取到ExecutorBizImpl对象
    Object serviceBean = this.serviceData.get(serviceKey);
    try {
        Class<?> serviceClass = serviceBean.getClass();
        //获取接收到的方法名
        String methodName = xxlRpcRequest.getMethodName();
        Class<?>[] parameterTypes = xxlRpcRequest.getParameterTypes();
        Object[] parameters = xxlRpcRequest.getParameters();
        Method method = serviceClass.getMethod(methodName, parameterTypes);
        method.setAccessible(true);
        Object result = method.invoke(serviceBean, parameters);
        xxlRpcResponse.setResult(result);
    } catch (Throwable var11) {
        logger.error("xxl-rpc provider invokeService error.", var11);
        xxlRpcResponse.setErrorMsg(ThrowableUtil.toString(var11));
    }
}

3.7、ExecutorBizImpl对象

3.8、执行调度任务的核心方法–run()方法

public ReturnT<String> run(TriggerParam triggerParam) {
    // load old：jobHandler + jobThread
    JobThread jobThread = XxlJobExecutor.loadJobThread(triggerParam.getJobId());
    IJobHandler jobHandler = jobThread!=null?jobThread.getHandler():null;
    String removeOldReason = null;

    // valid：jobHandler + jobThread
    GlueTypeEnum glueTypeEnum = GlueTypeEnum.match(triggerParam.getGlueType());
    //如果是定义在本的bean对象，那么从jobHandlerRepository对象中获取newJobHandler 
    if (GlueTypeEnum.BEAN == glueTypeEnum) {

        // new jobhandler
        IJobHandler newJobHandler = XxlJobExecutor.loadJobHandler(triggerParam.getExecutorHandler());

        // valid old jobThread
        if (jobThread!=null && jobHandler != newJobHandler) {
            // change handler, need kill old thread
            removeOldReason = "change jobhandler or glue type, and terminate the old job thread.";

            jobThread = null;
            jobHandler = null;
        }

        // valid handler
        if (jobHandler == null) {
            jobHandler = newJobHandler;
            if (jobHandler == null) {
                return new ReturnT<String>(ReturnT.FAIL_CODE, "job handler [" + triggerParam.getExecutorHandler() + "] not found.");
            }
        }

    } else if (GlueTypeEnum.GLUE_GROOVY == glueTypeEnum) {
    //如果是GLUE(Java)，那么获取triggerParam.getGlueSource()源码
    //反射实例化

        // valid old jobThread
        if (jobThread != null &&
                !(jobThread.getHandler() instanceof GlueJobHandler
                    && ((GlueJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
            // change handler or gluesource updated, need kill old thread
            removeOldReason = "change job source or glue type, and terminate the old job thread.";

            jobThread = null;
            jobHandler = null;
        }

        // valid handler
        if (jobHandler == null) {
            try {
                IJobHandler originJobHandler = GlueFactory.getInstance().loadNewInstance(triggerParam.getGlueSource());
                jobHandler = new GlueJobHandler(originJobHandler, triggerParam.getGlueUpdatetime());
            } catch (Exception e) {
                logger.error(e.getMessage(), e);
                return new ReturnT<String>(ReturnT.FAIL_CODE, e.getMessage());
            }
        }
    } else if (glueTypeEnum!=null && glueTypeEnum.isScript()) {

        // valid old jobThread
        if (jobThread != null &&
                !(jobThread.getHandler() instanceof ScriptJobHandler
                        && ((ScriptJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
            // change script or gluesource updated, need kill old thread
            removeOldReason = "change job source or glue type, and terminate the old job thread.";

            jobThread = null;
            jobHandler = null;
        }

        // valid handler
        if (jobHandler == null) {
            jobHandler = new ScriptJobHandler(triggerParam.getJobId(), triggerParam.getGlueUpdatetime(), triggerParam.getGlueSource(), GlueTypeEnum.match(triggerParam.getGlueType()));
        }
    } else {
        return new ReturnT<String>(ReturnT.FAIL_CODE, "glueType[" + triggerParam.getGlueType() + "] is not valid.");
    }

    // executor block strategy
    if (jobThread != null) {
        ExecutorBlockStrategyEnum blockStrategy = ExecutorBlockStrategyEnum.match(triggerParam.getExecutorBlockStrategy(), null);
        if (ExecutorBlockStrategyEnum.DISCARD_LATER == blockStrategy) {
            // discard when running
            if (jobThread.isRunningOrHasQueue()) {
                return new ReturnT<String>(ReturnT.FAIL_CODE, "block strategy effect："+ExecutorBlockStrategyEnum.DISCARD_LATER.getTitle());
            }
        } else if (ExecutorBlockStrategyEnum.COVER_EARLY == blockStrategy) {
            // kill running jobThread
            if (jobThread.isRunningOrHasQueue()) {
                removeOldReason = "block strategy effect：" + ExecutorBlockStrategyEnum.COVER_EARLY.getTitle();

                jobThread = null;
            }
        } else {
            // just queue trigger
        }
    }

    // replace thread (new or exists invalid)
    if (jobThread == null) {
   //执行handler方法
        jobThread = XxlJobExecutor.registJobThread(triggerParam.getJobId(), jobHandler, removeOldReason);
    }

    // push data to queue
    ReturnT<String> pushResult = jobThread.pushTriggerQueue(triggerParam);
    return pushResult;
}

3.9、registJobThread

public static JobThread registJobThread(int jobId, IJobHandler handler, String removeOldReason){
   JobThread newJobThread = new JobThread(jobId, handler);
   //调用线程
    newJobThread.start();
    logger.info(">>>>>>>>>>> xxl-job regist JobThread success, jobId:{}, handler:{}", new Object[]{jobId, handler});

    JobThread oldJobThread = jobThreadRepository.put(jobId, newJobThread);	// putIfAbsent | oh my god, map's put method return the old value!!!
    if (oldJobThread != null) {
        oldJobThread.toStop(removeOldReason);
        oldJobThread.interrupt();
    }

    return newJobThread;
}

查看run()方法：

//执行handler的init()方法
try {
   handler.init();
} catch (Throwable e) {
  logger.error(e.getMessage(), e);
}
//执行jobHandler的execute方法，这里会调用methodHandler的execute()方法，里面反射调了任务逻辑的方法
executeResult = handler.execute(triggerParam.getExecutorParams());
//将执行结果，推送到callBackQueue队列中
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTime(), executeResult));

二、调用中心项目

1、查看页面执行一次方法

在配置好定时任务后，点击执行一次，那么就会调用后台方法，执行一次任务方法，这个方法调用了trigger这个方法如下：

@RequestMapping("/trigger")
@ResponseBody
//@PermissionLimit(limit = false)
public ReturnT<String> triggerJob(int id, String executorParam) {
	// force cover job param
	if (executorParam == null) {
		executorParam = "";
	}

	JobTriggerPoolHelper.trigger(id, TriggerTypeEnum.MANUAL, -1, null, executorParam);
	return ReturnT.SUCCESS;
}

2、XxlJobTrigger.trigger

XxlJobTrigger.trigger(jobId, triggerType, failRetryCount, executorShardingParam, executorParam);

3、processTrigger

processTrigger(group, jobInfo, finalFailRetryCount, triggerType, i, group.getRegistryList().size());

triggerResult = runExecutor(triggerParam, address);

runExecutor方法核心代码

 try {
    ExecutorBiz executorBiz = XxlJobScheduler.getExecutorBiz(address);
    runResult = executorBiz.run(triggerParam);
} catch (Exception e) {
    logger.error(">>>>>>>>>>> xxl-job trigger error, please check if the executor[{}] is running.", address, e);
    runResult = new ReturnT<String>(ReturnT.FAIL_CODE, ThrowableUtil.toString(e));
}

getExecutorBiz

XxlRpcReferenceBean referenceBean = new XxlRpcReferenceBean();
referenceBean.setClient(NettyHttpClient.class);
referenceBean.setSerializer(HessianSerializer.class);
referenceBean.setCallType(CallType.SYNC);
referenceBean.setLoadBalance(LoadBalance.ROUND);
referenceBean.setIface(ExecutorBiz.class);
referenceBean.setVersion(null);
referenceBean.setTimeout(3000);
referenceBean.setAddress(address);
referenceBean.setAccessToken(XxlJobAdminConfig.getAdminConfig().getAccessToken());
referenceBean.setInvokeCallback(null);
referenceBean.setInvokerFactory(null);
//返回了referenceBean.getObject方法返回的对象
executorBiz = (ExecutorBiz) referenceBean.getObject();

executorBizRepository.put(address, executorBiz);
return executorBiz;

getOjbect()方法，返回了一代理对象，最终会调用代理类的invoke方法

public Object getObject() throws Exception {
        //实例化了NettyHttpClient对象
        this.initClient();
        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class[]{this.iface}, new InvocationHandler() {});
}

invoke方法，核心代码如下：

//发送请求到服务端
XxlRpcReferenceBean.this.clientInstance.asyncSend(finalAddress, xxlRpcRequest);
XxlRpcResponse xxlRpcResponse = futureResponse.get(XxlRpcReferenceBean.this.timeout, TimeUnit.MILLISECONDS);
if (xxlRpcResponse.getErrorMsg() != null) {
   throw new XxlRpcException(xxlRpcResponse.getErrorMsg());
}
var31 = xxlRpcResponse.getResult();

public void asyncSend(String address, XxlRpcRequest xxlRpcRequest) throws Exception {
        ConnectClient.asyncSend(xxlRpcRequest, address, this.connectClientImpl, this.xxlRpcReferenceBean);
    }

private Class<? extends ConnectClient> connectClientImpl = NettyHttpConnectClient.class;
//传入的是NettyHttpConnectClient.class
public static void asyncSend(XxlRpcRequest xxlRpcRequest, String address, Class<? extends ConnectClient> connectClientImpl, XxlRpcReferenceBean xxlRpcReferenceBean) throws Exception {
   //获取一个连接
    ConnectClient clientPool = getPool(address, connectClientImpl, xxlRpcReferenceBean);

    try {
        clientPool.send(xxlRpcRequest);
    } catch (Exception var6) {
        throw var6;
    }
}

ConnectClient connectClient_new = (ConnectClient)connectClientImpl.newInstance();
try {
    connectClient_new.init(address, xxlRpcReferenceBean.getSerializerInstance(), xxlRpcReferenceBean.getInvokerFactory());
    connectClientMap.put(address, connectClient_new);
} catch (Exception var9) {
    connectClient_new.close();
    throw var9;
}

connectClient_new.init方法，启动了一个netty客端，发送请求到服务端

this.address = address;
URL url = new URL(address);
this.host = url.getHost();
int port = url.getPort() > -1 ? url.getPort() : 80;
this.group = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap();
((Bootstrap)((Bootstrap)((Bootstrap)((Bootstrap)bootstrap.group(this.group)).channel(NioSocketChannel.class)).handler(new ChannelInitializer<SocketChannel>() {
    public void initChannel(SocketChannel channel) throws Exception {
        channel.pipeline().addLast(new ChannelHandler[]{new IdleStateHandler(0L, 0L, 30L, TimeUnit.SECONDS)}).addLast(new ChannelHandler[]{new HttpClientCodec()}).addLast(new ChannelHandler[]{new HttpObjectAggregator(5242880)}).addLast(new ChannelHandler[]{new NettyHttpClientHandler(xxlRpcInvokerFactory, serializer, NettyHttpConnectClient.this)});
    }
})).option(ChannelOption.SO_KEEPALIVE, true)).option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10000);
this.channel = bootstrap.connect(this.host, port).sync().channel();
this.serializer = serializer;

三、总结

执行器项目启了一个netty服务端接收数据，根据接收参数执行不同的任务方法
调用中心项目启了一个Netty客户发送数据