SpringCloud源码剖析-Eureka Client取消注册

@SingletonpublicclassDiscoveryClientimplementsEurekaClient {
    ....省略部分代码...
/**//关闭Eureak Client，从Eureak Server中取消服务的注册* Shuts down Eureka Client. Also sends a deregistration request to the* eureka server.*/@PreDestroy@Overridepublicsynchronizedvoidshutdown() {
if (isShutdown.compareAndSet(false, true)) {
logger.info("Shutting down DiscoveryClient ...");
//1.移除掉服务状态监听器if (statusChangeListener!=null&&applicationInfoManager!=null) {
applicationInfoManager.unregisterStatusChangeListener(statusChangeListener.getId());
            }
//2.注销定时任务cancelScheduledTasks();
// If APPINFO was registered//如果开启了shouldUnregisterOnShutdown 取消注册(默认true)，if (applicationInfoManager!=null&&clientConfig.shouldRegisterWithEureka()
&&clientConfig.shouldUnregisterOnShutdown()) {
//3.修改实例的注册状态为 DOWNapplicationInfoManager.setInstanceStatus(InstanceStatus.DOWN);
//4.取消注册unregister();
            }
//5.注销eurekaTransportif (eurekaTransport!=null) {
eurekaTransport.shutdown();
            }
//6.注销心跳状态监视器heartbeatStalenessMonitor.shutdown();
//7.注销注册表状态监视器registryStalenessMonitor.shutdown();
logger.info("Completed shut down of DiscoveryClient");
        }
    }
//注销定时任务privatevoidcancelScheduledTasks() {
if (instanceInfoReplicator!=null) {
instanceInfoReplicator.stop();
        }
if (heartbeatExecutor!=null) {
heartbeatExecutor.shutdownNow();
        }
if (cacheRefreshExecutor!=null) {
cacheRefreshExecutor.shutdownNow();
        }
if (scheduler!=null) {
scheduler.shutdownNow();
        }
    }
//注销EurekaTransport ，privatestaticfinalclassEurekaTransport {
privateClosableResolverbootstrapResolver;
privateTransportClientFactorytransportClientFactory;
privateEurekaHttpClientregistrationClient;
privateEurekaHttpClientFactoryregistrationClientFactory;
privateEurekaHttpClientqueryClient;
privateEurekaHttpClientFactoryqueryClientFactory;
voidshutdown() {
if (registrationClientFactory!=null) {
registrationClientFactory.shutdown();
            }
if (queryClientFactory!=null) {
queryClientFactory.shutdown();
            }
if (registrationClient!=null) {
registrationClient.shutdown();
            }
if (queryClient!=null) {
queryClient.shutdown();
            }
if (transportClientFactory!=null) {
transportClientFactory.shutdown();
            }
if (bootstrapResolver!=null) {
bootstrapResolver.shutdown();
            }
        }
    }

/**向eureka发送取消注册请求* unregister w/ the eureka service.*/voidunregister() {
// It can be null if shouldRegisterWithEureka == falseif(eurekaTransport!=null&&eurekaTransport.registrationClient!=null) {
try {
logger.info("Unregistering ...");
//向eureka发送取消注册的http请求EurekaHttpResponse<Void>httpResponse=eurekaTransport.registrationClient.cancel(instanceInfo.getAppName(), instanceInfo.getId());
logger.info(PREFIX+"{} - deregister  status: {}", appPathIdentifier, httpResponse.getStatusCode());
        } catch (Exceptione) {
logger.error(PREFIX+"{} - de-registration failed{}", appPathIdentifier, e.getMessage(), e);
        }
    }
}

@OverridepublicEurekaHttpResponse<Void>cancel(StringappName, Stringid) {
StringurlPath="apps/"+appName+'/'+id;
ClientResponseresponse=null;
try {
BuilderresourceBuilder=jerseyClient.resource(serviceUrl).path(urlPath).getRequestBuilder();
addExtraHeaders(resourceBuilder);
//发送Delete请求response=resourceBuilder.delete(ClientResponse.class);
returnanEurekaHttpResponse(response.getStatus()).headers(headersOf(response)).build();
    } finally {
if (logger.isDebugEnabled()) {
logger.debug("Jersey HTTP DELETE {}/{}; statusCode={}", serviceUrl, urlPath, response==null?"N/A" : response.getStatus());
        }
if (response!=null) {
response.close();
        }
    }
}