Spring Cloud Ribbon的原理

 1 @Configuration
 2 @Conditional({RibbonAutoConfiguration.RibbonClassesConditions.class})
 3 @RibbonClients
 4 @AutoConfigureAfter(
 5     name = {"org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration"}
 6 )
 7 @AutoConfigureBefore({LoadBalancerAutoConfiguration.class, AsyncLoadBalancerAutoConfiguration.class})
 8 @EnableConfigurationProperties({RibbonEagerLoadProperties.class, ServerIntrospectorProperties.class})
 9 public class RibbonAutoConfiguration {
10     @Autowired(
11         required = false
12     )
13     private List<RibbonClientSpecification> configurations = new ArrayList();
14     @Autowired
15     private RibbonEagerLoadProperties ribbonEagerLoadProperties;
16 
17     //...略
18 
19     @Bean
20     @ConditionalOnMissingBean({LoadBalancerClient.class})
21     public LoadBalancerClient loadBalancerClient() {
22         return new RibbonLoadBalancerClient(this.springClientFactory());
23     }
24 
25     // ....略
26 
27 }    

 1 @Configuration(proxyBeanMethods = false)
 2 @ConditionalOnClass(RestTemplate.class)
 3 @ConditionalOnBean(LoadBalancerClient.class)
 4 @EnableConfigurationProperties(LoadBalancerRetryProperties.class)
 5 public class LoadBalancerAutoConfiguration {
 6 
 7     @LoadBalanced
 8     @Autowired(required = false)
 9     private List<RestTemplate> restTemplates = Collections.emptyList();
10 
11     @Autowired(required = false)
12     private List<LoadBalancerRequestTransformer> transformers = Collections.emptyList();
13 
14     @Bean
15     public SmartInitializingSingleton loadBalancedRestTemplateInitializerDeprecated(
16             final ObjectProvider<List<RestTemplateCustomizer>> restTemplateCustomizers) {
17         return () -> restTemplateCustomizers.ifAvailable(customizers -> {
18             for (RestTemplate restTemplate : LoadBalancerAutoConfiguration.this.restTemplates) {
19                 for (RestTemplateCustomizer customizer : customizers) {
20                     customizer.customize(restTemplate);
21                 }
22             }
23         });
24     }
25 
26     @Bean
27     @ConditionalOnMissingBean
28     public LoadBalancerRequestFactory loadBalancerRequestFactory(
29             LoadBalancerClient loadBalancerClient) {
30         return new LoadBalancerRequestFactory(loadBalancerClient, this.transformers);
31     }
32 
33     @Configuration(proxyBeanMethods = false)
34     @ConditionalOnMissingClass("org.springframework.retry.support.RetryTemplate")
35     static class LoadBalancerInterceptorConfig {
36 
37         @Bean
38         public LoadBalancerInterceptor ribbonInterceptor(
39                 LoadBalancerClient loadBalancerClient,
40                 LoadBalancerRequestFactory requestFactory) {
41             return new LoadBalancerInterceptor(loadBalancerClient, requestFactory);
42         }
43 
44         @Bean
45         @ConditionalOnMissingBean
46         public RestTemplateCustomizer restTemplateCustomizer(
47                 final LoadBalancerInterceptor loadBalancerInterceptor) {
48             return restTemplate -> {
49                 List<ClientHttpRequestInterceptor> list = new ArrayList<>(
50                         restTemplate.getInterceptors());
51                 list.add(loadBalancerInterceptor);
52                 restTemplate.setInterceptors(list);
53             };
54         }
55 
56     }
57 
58         // .....略    
59 }
60 
61