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本文主要研究一下spring cloud netflix ribbon的eager load
RibbonAutoConfiguration
spring-cloud-netflix-ribbon-2.1.1.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/RibbonAutoConfiguration.java
@Configuration
@Conditional(RibbonAutoConfiguration.RibbonClassesConditions.class)
@RibbonClients
@AutoConfigureAfter(name = "org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration")
@AutoConfigureBefore({ LoadBalancerAutoConfiguration.class,
AsyncLoadBalancerAutoConfiguration.class })
@EnableConfigurationProperties({ RibbonEagerLoadProperties.class,
ServerIntrospectorProperties.class })
public class RibbonAutoConfiguration {
@Autowired(required = false)
private List configurations = new ArrayList<>();
@Autowired
private RibbonEagerLoadProperties ribbonEagerLoadProperties;
@Bean
public HasFeatures ribbonFeature() {
return HasFeatures.namedFeature("Ribbon", Ribbon.class);
}
@Bean
public SpringClientFactory springClientFactory() {
SpringClientFactory factory = new SpringClientFactory();
factory.setConfigurations(this.configurations);
return factory;
}
@Bean
@ConditionalOnMissingBean(LoadBalancerClient.class)
public LoadBalancerClient loadBalancerClient() {
return new RibbonLoadBalancerClient(springClientFactory());
}
@Bean
@ConditionalOnClass(name = "org.springframework.retry.support.RetryTemplate")
@ConditionalOnMissingBean
public LoadBalancedRetryFactory loadBalancedRetryPolicyFactory(
final SpringClientFactory clientFactory) {
return new RibbonLoadBalancedRetryFactory(clientFactory);
}
@Bean
@ConditionalOnMissingBean
public PropertiesFactory propertiesFactory() {
return new PropertiesFactory();
}
@Bean
@ConditionalOnProperty("ribbon.eager-load.enabled")
public RibbonApplicationContextInitializer ribbonApplicationContextInitializer() {
return new RibbonApplicationContextInitializer(springClientFactory(),
ribbonEagerLoadProperties.getClients());
}
@Configuration
@ConditionalOnClass(HttpRequest.class)
@ConditionalOnRibbonRestClient
protected static class RibbonClientHttpRequestFactoryConfiguration {
@Autowired
private SpringClientFactory springClientFactory;
@Bean
public RestTemplateCustomizer restTemplateCustomizer(
final RibbonClientHttpRequestFactory ribbonClientHttpRequestFactory) {
return restTemplate -> restTemplate
.setRequestFactory(ribbonClientHttpRequestFactory);
}
@Bean
public RibbonClientHttpRequestFactory ribbonClientHttpRequestFactory() {
return new RibbonClientHttpRequestFactory(this.springClientFactory);
}
}
// TODO: support for autoconfiguring restemplate to use apache http client or okhttp
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Conditional(OnRibbonRestClientCondition.class)
@interface ConditionalOnRibbonRestClient {
}
private static class OnRibbonRestClientCondition extends AnyNestedCondition {
OnRibbonRestClientCondition() {
super(ConfigurationPhase.REGISTER_BEAN);
}
@Deprecated // remove in Edgware"
@ConditionalOnProperty("ribbon.http.client.enabled")
static class ZuulProperty {
}
@ConditionalOnProperty("ribbon.restclient.enabled")
static class RibbonProperty {
}
}
/**
* {@link AllNestedConditions} that checks that either multiple classes are present.
*/
static class RibbonClassesConditions extends AllNestedConditions {
RibbonClassesConditions() {
super(ConfigurationPhase.PARSE_CONFIGURATION);
}
@ConditionalOnClass(IClient.class)
static class IClientPresent {
}
@ConditionalOnClass(RestTemplate.class)
static class RestTemplatePresent {
}
@ConditionalOnClass(AsyncRestTemplate.class)
static class AsyncRestTemplatePresent {
}
@ConditionalOnClass(Ribbon.class)
static class RibbonPresent {
}
}
} - RibbonAutoConfiguration启用了RibbonEagerLoadProperties、ServerIntrospectorProperties两个配置，这里主要是注册了SpringClientFactory，创建LoadBalancerClient、LoadBalancedRetryFactory、RibbonApplicationContextInitializer、RestTemplateCustomizer及RibbonClientHttpRequestFactory
RibbonApplicationContextInitializer
spring-cloud-netflix-ribbon-2.1.1.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/RibbonApplicationContextInitializer.java
public class RibbonApplicationContextInitializer
implements ApplicationListener {
private final SpringClientFactory springClientFactory;
// List of Ribbon client names
private final List clientNames;
public RibbonApplicationContextInitializer(SpringClientFactory springClientFactory,
List clientNames) {
this.springClientFactory = springClientFactory;
this.clientNames = clientNames;
}
protected void initialize() {
if (clientNames != null) {
for (String clientName : clientNames) {
this.springClientFactory.getContext(clientName);
}
}
}
@Override
public void onApplicationEvent(ApplicationReadyEvent event) {
initialize();
}
} - RibbonApplicationContextInitializer实现了ApplicationListener接口，其响应ApplicationReadyEvent事件执行initialize操作，这里主要是挨个对配置的clientNames执行springClientFactory.getContext(clientName)操作
SpringClientFactory
spring-cloud-netflix-ribbon-2.1.1.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/SpringClientFactory.java
public class SpringClientFactory extends NamedContextFactory {
//......
protected AnnotationConfigApplicationContext getContext(String name) {
return super.getContext(name);
}
//......
} - SpringClientFactory的getContext方法调用了父类NamedContextFactory的getContext
NamedContextFactory
spring-cloud-context-2.2.0.M1-sources.jar!/org/springframework/cloud/context/named/NamedContextFactory.java
public abstract class NamedContextFactory
implements DisposableBean, ApplicationContextAware {
//......
protected AnnotationConfigApplicationContext getContext(String name) {
if (!this.contexts.containsKey(name)) {
synchronized (this.contexts) {
if (!this.contexts.containsKey(name)) {
this.contexts.put(name, createContext(name));
}
}
}
return this.contexts.get(name);
}
protected AnnotationConfigApplicationContext createContext(String name) {
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
if (this.configurations.containsKey(name)) {
for (Class configuration : this.configurations.get(name)
.getConfiguration()) {
context.register(configuration);
}
}
for (Map.Entry entry : this.configurations.entrySet()) {
if (entry.getKey().startsWith("default.")) {
for (Class configuration : entry.getValue().getConfiguration()) {
context.register(configuration);
}
}
}
context.register(PropertyPlaceholderAutoConfiguration.class,
this.defaultConfigType);
context.getEnvironment().getPropertySources().addFirst(new MapPropertySource(
this.propertySourceName,
Collections.singletonMap(this.propertyName, name)));
if (this.parent != null) {
// Uses Environment from parent as well as beans
context.setParent(this.parent);
// jdk11 issue
// https://github.com/spring-cloud/spring-cloud-netflix/issues/3101
context.setClassLoader(this.parent.getClassLoader());
}
context.setDisplayName(generateDisplayName(name));
context.refresh();
return context;
}
//......
} - NamedContextFactory的getContext主要是返回或者创建AnnotationConfigApplicationContext
小结
- RibbonAutoConfiguration启用了RibbonEagerLoadProperties、ServerIntrospectorProperties两个配置，这里主要是注册了SpringClientFactory，创建LoadBalancerClient、LoadBalancedRetryFactory、RibbonApplicationContextInitializer、RestTemplateCustomizer及RibbonClientHttpRequestFactory
- RibbonApplicationContextInitializer实现了ApplicationListener接口，其响应ApplicationReadyEvent事件执行initialize操作，这里主要是挨个对配置的clientNames执行springClientFactory.getContext(clientName)操作
- SpringClientFactory的getContext方法调用了父类NamedContextFactory的getContext；NamedContextFactory的getContext主要是返回或者创建AnnotationConfigApplicationContext
doc
- RibbonClientConfiguration