Feign注解源码
Feign注解源码
EnableFeignClients注解背后加载流程
- @EnableFeignClients的
@Import(FeignClientsRegistrar.class)实现注册 class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar, ResourceLoaderAware, EnvironmentAware注册类
@Override public void registerBeanDefinitions(AnnotationMetadata metadata, BeanDefinitionRegistry registry) { //注册默认配置 registerDefaultConfiguration(metadata, registry); registerFeignClients(metadata, registry); }1.1 registerDefaultConfiguration
private void registerDefaultConfiguration(AnnotationMetadata metadata, BeanDefinitionRegistry registry) { //获取@EnableFeignClients注解中声明的变量值 Map<String, Object> defaultAttrs = metadata .getAnnotationAttributes(EnableFeignClients.class.getName(), true); if (defaultAttrs != null && defaultAttrs.containsKey("defaultConfiguration")) { String name; //该方法是否继承任何类 if (metadata.hasEnclosingClass()) { name = "default." + metadata.getEnclosingClassName(); } else { //name = "default" + 包名 + 启动类 name = "default." + metadata.getClassName(); } //构造上下文中需要用到的Bean信息并注册 registerClientConfiguration(registry, name, defaultAttrs.get("defaultConfiguration")); } } private void registerClientConfiguration(BeanDefinitionRegistry registry, Object name, Object configuration) { //构造FeignClientSpecification类 BeanDefinitionBuilder builder = BeanDefinitionBuilder .genericBeanDefinition(FeignClientSpecification.class); //把main函数类名传入 builder.addConstructorArgValue(name); //传入配置项 builder.addConstructorArgValue(configuration); //通过registerBeanDefinition注册Bean registry.registerBeanDefinition( name + "." + FeignClientSpecification.class.getSimpleName(), builder.getBeanDefinition()); }