springboot项目启动默认是加载classpath下spring.factories文件中的org.springframework.boot.autoconfigure.EnableAutoConfiguration属性的自动配置类列表。
Eureka客户端加载过程
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源码分析
package org.springframework.cloud.netflix.eureka;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.Map;
import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.EurekaInstanceConfig;
import com.netflix.appinfo.HealthCheckHandler;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.discovery.AbstractDiscoveryClientOptionalArgs;
import com.netflix.discovery.EurekaClient;
import com.netflix.discovery.EurekaClientConfig;
import org.springframework.aop.support.AopUtils;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.actuate.autoconfigure.health.ConditionalOnEnabledHealthIndicator;
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.SearchStrategy;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cloud.autoconfigure.RefreshAutoConfiguration;
import org.springframework.cloud.client.CommonsClientAutoConfiguration;
import org.springframework.cloud.client.ConditionalOnDiscoveryEnabled;
import org.springframework.cloud.client.actuator.HasFeatures;
import org.springframework.cloud.client.discovery.noop.NoopDiscoveryClientAutoConfiguration;
import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationProperties;
import org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguration;
import org.springframework.cloud.commons.util.InetUtils;
import org.springframework.cloud.context.scope.refresh.RefreshScope;
import org.springframework.cloud.netflix.eureka.config.DiscoveryClientOptionalArgsConfiguration;
import org.springframework.cloud.netflix.eureka.metadata.DefaultManagementMetadataProvider;
import org.springframework.cloud.netflix.eureka.metadata.ManagementMetadata;
import org.springframework.cloud.netflix.eureka.metadata.ManagementMetadataProvider;
import org.springframework.cloud.netflix.eureka.serviceregistry.EurekaAutoServiceRegistration;
import org.springframework.cloud.netflix.eureka.serviceregistry.EurekaRegistration;
import org.springframework.cloud.netflix.eureka.serviceregistry.EurekaServiceRegistry;
import org.springframework.cloud.util.ProxyUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Conditional;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.Lazy;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.util.StringUtils;
import static org.springframework.cloud.commons.util.IdUtils.getDefaultInstanceId;
@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnClass(EurekaClientConfig.class)
@Import(DiscoveryClientOptionalArgsConfiguration.class)
@ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
@ConditionalOnDiscoveryEnabled
@AutoConfigureBefore({ NoopDiscoveryClientAutoConfiguration.class,
CommonsClientAutoConfiguration.class, ServiceRegistryAutoConfiguration.class })
@AutoConfigureAfter(name = {
"org.springframework.cloud.autoconfigure.RefreshAutoConfiguration",
"org.springframework.cloud.netflix.eureka.EurekaDiscoveryClientConfiguration",
"org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration" })
public class EurekaClientAutoConfiguration {
private ConfigurableEnvironment env;
public EurekaClientAutoConfiguration(ConfigurableEnvironment env) {
this.env = env;
}
@Bean
public HasFeatures eurekaFeature() {
return HasFeatures.namedFeature("Eureka Client", EurekaClient.class);
}
// 加载配置文件 EurekaClientConfigBean
@Bean
@ConditionalOnMissingBean(value = EurekaClientConfig.class,
search = SearchStrategy.CURRENT)
public EurekaClientConfigBean eurekaClientConfigBean(ConfigurableEnvironment env) {
EurekaClientConfigBean client = new EurekaClientConfigBean();
if ("bootstrap".equals(this.env.getProperty("spring.config.name"))) {
// We don't register during bootstrap by default, but there will be another
// chance later.
client.setRegisterWithEureka(false);
}
return client;
}
@Bean
@ConditionalOnMissingBean
public ManagementMetadataProvider serviceManagementMetadataProvider() {
return new DefaultManagementMetadataProvider();
}
private String getProperty(String property) {
return this.env.containsProperty(property) ? this.env.getProperty(property) : "";
}
// 加载配置文件 EurekaInstanceConfigBean
@Bean
@ConditionalOnMissingBean(value = EurekaInstanceConfig.class,
search = SearchStrategy.CURRENT)
public EurekaInstanceConfigBean eurekaInstanceConfigBean(InetUtils inetUtils,
ManagementMetadataProvider managementMetadataProvider) {
String hostname = getProperty("eureka.instance.hostname");
boolean preferIpAddress = Boolean
.parseBoolean(getProperty("eureka.instance.prefer-ip-address"));
String ipAddress = getProperty("eureka.instance.ip-address");
boolean isSecurePortEnabled = Boolean
.parseBoolean(getProperty("eureka.instance.secure-port-enabled"));
String serverContextPath = env.getProperty("server.servlet.context-path", "/");
int serverPort = Integer.parseInt(
env.getProperty("server.port", env.getProperty("port", "8080")));
Integer managementPort = env.getProperty("management.server.port", Integer.class);
String managementContextPath = env
.getProperty("management.server.servlet.context-path");
Integer jmxPort = env.getProperty("com.sun.management.jmxremote.port",
Integer.class);
EurekaInstanceConfigBean instance = new EurekaInstanceConfigBean(inetUtils);
instance.setNonSecurePort(serverPort);
instance.setInstanceId(getDefaultInstanceId(env));
instance.setPreferIpAddress(preferIpAddress);
instance.setSecurePortEnabled(isSecurePortEnabled);
if (StringUtils.hasText(ipAddress)) {
instance.setIpAddress(ipAddress);
}
if (isSecurePortEnabled) {
instance.setSecurePort(serverPort);
}
if (StringUtils.hasText(hostname)) {
instance.setHostname(hostname);
}
String statusPageUrlPath = getProperty("eureka.instance.status-page-url-path");
String healthCheckUrlPath = getProperty("eureka.instance.health-check-url-path");
if (StringUtils.hasText(statusPageUrlPath)) {
instance.setStatusPageUrlPath(statusPageUrlPath);
}
if (StringUtils.hasText(healthCheckUrlPath)) {
instance.setHealthCheckUrlPath(healthCheckUrlPath);
}
ManagementMetadata metadata = managementMetadataProvider.get(instance, serverPort,
serverContextPath, managementContextPath, managementPort);
if (metadata != null) {
instance.setStatusPageUrl(metadata.getStatusPageUrl());
instance.setHealthCheckUrl(metadata.getHealthCheckUrl());
if (instance.isSecurePortEnabled()) {
instance.setSecureHealthCheckUrl(metadata.getSecureHealthCheckUrl());
}
Map<String, String> metadataMap = instance.getMetadataMap();
metadataMap.computeIfAbsent("management.port",
k -> String.valueOf(metadata.getManagementPort()));
}
else {
// without the metadata the status and health check URLs will not be set
// and the status page and health check url paths will not include the
// context path so set them here
if (StringUtils.hasText(managementContextPath)) {
instance.setHealthCheckUrlPath(
managementContextPath + instance.getHealthCheckUrlPath());
instance.setStatusPageUrlPath(
managementContextPath + instance.getStatusPageUrlPath());
}
}
setupJmxPort(instance, jmxPort);
return instance;
}
private void setupJmxPort(EurekaInstanceConfigBean instance, Integer jmxPort) {
Map<String, String> metadataMap = instance.getMetadataMap();
if (metadataMap.get("jmx.port") == null && jmxPort != null) {
metadataMap.put("jmx.port", String.valueOf(jmxPort));
}
}
@Bean
public EurekaServiceRegistry eurekaServiceRegistry() {
return new EurekaServiceRegistry();
}
// @Bean
// @ConditionalOnBean(AutoServiceRegistrationProperties.class)
// @ConditionalOnProperty(value =
// "spring.cloud.service-registry.auto-registration.enabled", matchIfMissing = true)
// public EurekaRegistration eurekaRegistration(EurekaClient eurekaClient,
// CloudEurekaInstanceConfig instanceConfig, ApplicationInfoManager
// applicationInfoManager, ObjectProvider<HealthCheckHandler> healthCheckHandler) {
// return EurekaRegistration.builder(instanceConfig)
// .with(applicationInfoManager)
// .with(eurekaClient)
// .with(healthCheckHandler)
// .build();
// }
// Eureka自动服务注册配置类
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
@ConditionalOnProperty(
value = "spring.cloud.service-registry.auto-registration.enabled",
matchIfMissing = true)
public EurekaAutoServiceRegistration eurekaAutoServiceRegistration(
ApplicationContext context, EurekaServiceRegistry registry,
EurekaRegistration registration) {
return new EurekaAutoServiceRegistration(context, registry, registration);
}
@Configuration(proxyBeanMethods = false)
@ConditionalOnMissingRefreshScope
protected static class EurekaClientConfiguration {
@Autowired
private ApplicationContext context;
@Autowired
private AbstractDiscoveryClientOptionalArgs<?> optionalArgs;
// 初始化EurekaClient
@Bean(destroyMethod = "shutdown")
@ConditionalOnMissingBean(value = EurekaClient.class,
search = SearchStrategy.CURRENT)
public EurekaClient eurekaClient(ApplicationInfoManager manager,
EurekaClientConfig config) {
return new CloudEurekaClient(manager, config, this.optionalArgs,
this.context);
}
@Bean
@ConditionalOnMissingBean(value = ApplicationInfoManager.class,
search = SearchStrategy.CURRENT)
public ApplicationInfoManager eurekaApplicationInfoManager(
EurekaInstanceConfig config) {
InstanceInfo instanceInfo = new InstanceInfoFactory().create(config);
return new ApplicationInfoManager(config, instanceInfo);
}
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
@ConditionalOnProperty(
value = "spring.cloud.service-registry.auto-registration.enabled",
matchIfMissing = true)
public EurekaRegistration eurekaRegistration(EurekaClient eurekaClient,
CloudEurekaInstanceConfig instanceConfig,
ApplicationInfoManager applicationInfoManager, @Autowired(
required = false) ObjectProvider<HealthCheckHandler> healthCheckHandler) {
return EurekaRegistration.builder(instanceConfig).with(applicationInfoManager)
.with(eurekaClient).with(healthCheckHandler).build();
}
}
@Configuration(proxyBeanMethods = false)
@ConditionalOnRefreshScope
protected static class RefreshableEurekaClientConfiguration {
@Autowired
private ApplicationContext context;
@Autowired
private AbstractDiscoveryClientOptionalArgs<?> optionalArgs;
@Bean(destroyMethod = "shutdown")
@ConditionalOnMissingBean(value = EurekaClient.class,
search = SearchStrategy.CURRENT)
@org.springframework.cloud.context.config.annotation.RefreshScope
@Lazy
public EurekaClient eurekaClient(ApplicationInfoManager manager,
EurekaClientConfig config, EurekaInstanceConfig instance,
@Autowired(required = false) HealthCheckHandler healthCheckHandler) {
// If we use the proxy of the ApplicationInfoManager we could run into a
// problem
// when shutdown is called on the CloudEurekaClient where the
// ApplicationInfoManager bean is
// requested but wont be allowed because we are shutting down. To avoid this
// we use the
// object directly.
ApplicationInfoManager appManager;
if (AopUtils.isAopProxy(manager)) {
appManager = ProxyUtils.getTargetObject(manager);
}
else {
appManager = manager;
}
CloudEurekaClient cloudEurekaClient = new CloudEurekaClient(appManager,
config, this.optionalArgs, this.context);
cloudEurekaClient.registerHealthCheck(healthCheckHandler);
return cloudEurekaClient;
}
@Bean
@ConditionalOnMissingBean(value = ApplicationInfoManager.class,
search = SearchStrategy.CURRENT)
@org.springframework.cloud.context.config.annotation.RefreshScope
@Lazy
public ApplicationInfoManager eurekaApplicationInfoManager(
EurekaInstanceConfig config) {
InstanceInfo instanceInfo = new InstanceInfoFactory().create(config);
return new ApplicationInfoManager(config, instanceInfo);
}
// 注册
@Bean
@org.springframework.cloud.context.config.annotation.RefreshScope
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
@ConditionalOnProperty(
value = "spring.cloud.service-registry.auto-registration.enabled",
matchIfMissing = true)
public EurekaRegistration eurekaRegistration(EurekaClient eurekaClient,
CloudEurekaInstanceConfig instanceConfig,
ApplicationInfoManager applicationInfoManager, @Autowired(
required = false) ObjectProvider<HealthCheckHandler> healthCheckHandler) {
return EurekaRegistration.builder(instanceConfig).with(applicationInfoManager)
.with(eurekaClient).with(healthCheckHandler).build();
}
}
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Conditional(OnMissingRefreshScopeCondition.class)
@interface ConditionalOnMissingRefreshScope {
}
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ConditionalOnClass(RefreshScope.class)
@ConditionalOnBean(RefreshAutoConfiguration.class)
@ConditionalOnProperty(value = "eureka.client.refresh.enable", havingValue = "true",
matchIfMissing = true)
@interface ConditionalOnRefreshScope {
}
private static class OnMissingRefreshScopeCondition extends AnyNestedCondition {
OnMissingRefreshScopeCondition() {
super(ConfigurationPhase.REGISTER_BEAN);
}
@ConditionalOnMissingClass("org.springframework.cloud.context.scope.refresh.RefreshScope")
static class MissingClass {
}
@ConditionalOnMissingBean(RefreshAutoConfiguration.class)
static class MissingScope {
}
@ConditionalOnProperty(value = "eureka.client.refresh.enable",
havingValue = "false")
static class OnPropertyDisabled {
}
}
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(Health.class)
protected static class EurekaHealthIndicatorConfiguration {
@Bean
@ConditionalOnMissingBean
@ConditionalOnEnabledHealthIndicator("eureka")
public EurekaHealthIndicator eurekaHealthIndicator(EurekaClient eurekaClient,
EurekaInstanceConfig instanceConfig, EurekaClientConfig clientConfig) {
return new EurekaHealthIndicator(eurekaClient, instanceConfig, clientConfig);
}
}
}
重点代码块如下：
配置文件的加载EurekaClientConfigBean、EurekaInstanceConfigBean
EurekaAutoServiceRegistration自动服务注册类，实现了SmartLifecycle接口（bean容器启动后调用）。
eurekaClient初始化。
image.png
// DiscoveryClient构造方法
{
if (args != null) {
this.healthCheckHandlerProvider = args.healthCheckHandlerProvider;
this.healthCheckCallbackProvider = args.healthCheckCallbackProvider;
this.eventListeners.addAll(args.getEventListeners());
this.preRegistrationHandler = args.preRegistrationHandler;
} else {
this.healthCheckCallbackProvider = null;
this.healthCheckHandlerProvider = null;
this.preRegistrationHandler = null;
}
this.applicationInfoManager = applicationInfoManager;
InstanceInfo myInfo = applicationInfoManager.getInfo();
clientConfig = config;
staticClientConfig = clientConfig;
transportConfig = config.getTransportConfig();
instanceInfo = myInfo;
if (myInfo != null) {
appPathIdentifier = instanceInfo.getAppName() + "/" + instanceInfo.getId();
} else {
logger.warn("Setting instanceInfo to a passed in null value");
}
this.backupRegistryProvider = backupRegistryProvider;
this.endpointRandomizer = endpointRandomizer;
this.urlRandomizer = new EndpointUtils.InstanceInfoBasedUrlRandomizer(instanceInfo);
localRegionApps.set(new Applications());
fetchRegistryGeneration = new AtomicLong(0);
remoteRegionsToFetch = new AtomicReference<String>(clientConfig.fetchRegistryForRemoteRegions());
remoteRegionsRef = new AtomicReference<>(remoteRegionsToFetch.get() == null ? null : remoteRegionsToFetch.get().split(","));
if (config.shouldFetchRegistry()) {
this.registryStalenessMonitor = new ThresholdLevelsMetric(this, METRIC_REGISTRY_PREFIX + "lastUpdateSec_", new long[]{15L, 30L, 60L, 120L, 240L, 480L});
} else {
this.registryStalenessMonitor = ThresholdLevelsMetric.NO_OP_METRIC;
}
if (config.shouldRegisterWithEureka()) {
this.heartbeatStalenessMonitor = new ThresholdLevelsMetric(this, METRIC_REGISTRATION_PREFIX + "lastHeartbeatSec_", new long[]{15L, 30L, 60L, 120L, 240L, 480L});
} else {
this.heartbeatStalenessMonitor = ThresholdLevelsMetric.NO_OP_METRIC;
}
logger.info("Initializing Eureka in region {}", clientConfig.getRegion());
if (!config.shouldRegisterWithEureka() && !config.shouldFetchRegistry()) {
logger.info("Client configured to neither register nor query for data.");
scheduler = null;
heartbeatExecutor = null;
cacheRefreshExecutor = null;
eurekaTransport = null;
instanceRegionChecker = new InstanceRegionChecker(new PropertyBasedAzToRegionMapper(config), clientConfig.getRegion());
// This is a bit of hack to allow for existing code using DiscoveryManager.getInstance()
// to work with DI'd DiscoveryClient
DiscoveryManager.getInstance().setDiscoveryClient(this);
DiscoveryManager.getInstance().setEurekaClientConfig(config);
initTimestampMs = System.currentTimeMillis();
logger.info("Discovery Client initialized at timestamp {} with initial instances count: {}",
initTimestampMs, this.getApplications().size());
return; // no need to setup up an network tasks and we are done
}
try {
// default size of 2 - 1 each for heartbeat and cacheRefresh
scheduler = Executors.newScheduledThreadPool(2,
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-%d")
.setDaemon(true)
.build());
heartbeatExecutor = new ThreadPoolExecutor(
1, clientConfig.getHeartbeatExecutorThreadPoolSize(), 0, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-HeartbeatExecutor-%d")
.setDaemon(true)
.build()
); // use direct handoff
cacheRefreshExecutor = new ThreadPoolExecutor(
1, clientConfig.getCacheRefreshExecutorThreadPoolSize(), 0, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
new ThreadFactoryBuilder()
.setNameFormat("DiscoveryClient-CacheRefreshExecutor-%d")
.setDaemon(true)
.build()
); // use direct handoff
eurekaTransport = new EurekaTransport();
scheduleServerEndpointTask(eurekaTransport, args);
AzToRegionMapper azToRegionMapper;
if (clientConfig.shouldUseDnsForFetchingServiceUrls()) {
azToRegionMapper = new DNSBasedAzToRegionMapper(clientConfig);
} else {
azToRegionMapper = new PropertyBasedAzToRegionMapper(clientConfig);
}
if (null != remoteRegionsToFetch.get()) {
azToRegionMapper.setRegionsToFetch(remoteRegionsToFetch.get().split(","));
}
instanceRegionChecker = new InstanceRegionChecker(azToRegionMapper, clientConfig.getRegion());
} catch (Throwable e) {
throw new RuntimeException("Failed to initialize DiscoveryClient!", e);
}
if (clientConfig.shouldFetchRegistry() && !fetchRegistry(false)) {
fetchRegistryFromBackup();
}
// call and execute the pre registration handler before all background tasks (inc registration) is started
if (this.preRegistrationHandler != null) {
this.preRegistrationHandler.beforeRegistration();
}
if (clientConfig.shouldRegisterWithEureka() && clientConfig.shouldEnforceRegistrationAtInit()) {
try {
if (!register() ) {
throw new IllegalStateException("Registration error at startup. Invalid server response.");
}
} catch (Throwable th) {
logger.error("Registration error at startup: {}", th.getMessage());
throw new IllegalStateException(th);
}
}
// finally, init the schedule tasks (e.g. cluster resolvers, heartbeat, instanceInfo replicator, fetch
initScheduledTasks();
try {
Monitors.registerObject(this);
} catch (Throwable e) {
logger.warn("Cannot register timers", e);
}
// This is a bit of hack to allow for existing code using DiscoveryManager.getInstance()
// to work with DI'd DiscoveryClient
DiscoveryManager.getInstance().setDiscoveryClient(this);
DiscoveryManager.getInstance().setEurekaClientConfig(config);
initTimestampMs = System.currentTimeMillis();
logger.info("Discovery Client initialized at timestamp {} with initial instances count: {}",
initTimestampMs, this.getApplications().size());
}
/**
* Initializes all scheduled tasks.
*/
private void initScheduledTasks() {
if (clientConfig.shouldFetchRegistry()) {
// registry cache refresh timer
int registryFetchIntervalSeconds = clientConfig.getRegistryFetchIntervalSeconds();
int expBackOffBound = clientConfig.getCacheRefreshExecutorExponentialBackOffBound();
cacheRefreshTask = new TimedSupervisorTask(
"cacheRefresh",
scheduler,
cacheRefreshExecutor,
registryFetchIntervalSeconds,
TimeUnit.SECONDS,
expBackOffBound,
new CacheRefreshThread()
);
scheduler.schedule(
cacheRefreshTask,
registryFetchIntervalSeconds, TimeUnit.SECONDS);
}
if (clientConfig.shouldRegisterWithEureka()) {
int renewalIntervalInSecs = instanceInfo.getLeaseInfo().getRenewalIntervalInSecs();
int expBackOffBound = clientConfig.getHeartbeatExecutorExponentialBackOffBound();
logger.info("Starting heartbeat executor: " + "renew interval is: {}", renewalIntervalInSecs);
// Heartbeat timer
heartbeatTask = new TimedSupervisorTask(
"heartbeat",
scheduler,
heartbeatExecutor,
renewalIntervalInSecs,
TimeUnit.SECONDS,
expBackOffBound,
new HeartbeatThread()
);
scheduler.schedule(
heartbeatTask,
renewalIntervalInSecs, TimeUnit.SECONDS);
// InstanceInfo replicator
instanceInfoReplicator = new InstanceInfoReplicator(
this,
instanceInfo,
clientConfig.getInstanceInfoReplicationIntervalSeconds(),
2); // burstSize
statusChangeListener = new ApplicationInfoManager.StatusChangeListener() {
@Override
public String getId() {
return "statusChangeListener";
}
@Override
public void notify(StatusChangeEvent statusChangeEvent) {
if (InstanceStatus.DOWN == statusChangeEvent.getStatus() ||
InstanceStatus.DOWN == statusChangeEvent.getPreviousStatus()) {
// log at warn level if DOWN was involved
logger.warn("Saw local status change event {}", statusChangeEvent);
} else {
logger.info("Saw local status change event {}", statusChangeEvent);
}
instanceInfoReplicator.onDemandUpdate();
}
};
if (clientConfig.shouldOnDemandUpdateStatusChange()) {
applicationInfoManager.registerStatusChangeListener(statusChangeListener);
}
instanceInfoReplicator.start(clientConfig.getInitialInstanceInfoReplicationIntervalSeconds());
} else {
logger.info("Not registering with Eureka server per configuration");
}
}
启动关键性代码需仔细阅读。
CloudEurekaClient私有成员EurekaHttpClient。
private AtomicReference<EurekaHttpClient> eurekaHttpClient = new AtomicReference<>();
EurekaHttpClient getEurekaHttpClient() {
if (this.eurekaHttpClient.get() == null) {
try {
Object eurekaTransport = this.eurekaTransportField.get(this);
Field registrationClientField = ReflectionUtils
.findField(eurekaTransport.getClass(), "registrationClient");
ReflectionUtils.makeAccessible(registrationClientField);
this.eurekaHttpClient.compareAndSet(null,
(EurekaHttpClient) registrationClientField.get(eurekaTransport));
}
catch (IllegalAccessException e) {
log.error("error getting EurekaHttpClient", e);
}
}
return this.eurekaHttpClient.get();
}
Client端启动过程
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