Dubbo 源码阅读（五）@EnableDubbo

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
@EnableDubboConfig   //解析属性文件
@DubboComponentScan  //扫描@Service和@reference
public @interface EnableDubbo {

    @AliasFor(annotation = DubboComponentScan.class, attribute = "basePackages")
    String[] scanBasePackages() default {};

    @AliasFor(annotation = DubboComponentScan.class, attribute = "basePackageClasses")
    Class<?>[] scanBasePackageClasses() default {};

    @AliasFor(annotation = EnableDubboConfig.class, attribute = "multiple")
    boolean multipleConfig() default false;
}

@EnableDubboConfig

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
@Import(DubboConfigConfigurationSelector.class)
public @interface EnableDubboConfig {
    boolean multiple() default false;
}

跟 DubboConfigConfigurationSelector：

public class DubboConfigConfigurationSelector implements ImportSelector, Ordered {

    @Override
    public String[] selectImports(AnnotationMetadata importingClassMetadata) {

        AnnotationAttributes attributes = AnnotationAttributes.fromMap(
                importingClassMetadata.getAnnotationAttributes(EnableDubboConfig.class.getName()));

        boolean multiple = attributes.getBoolean("multiple");

        if (multiple) {
            return of(DubboConfigConfiguration.Multiple.class.getName());
        } else {
            return of(DubboConfigConfiguration.Single.class.getName());
        }
    }

    private static <T> T[] of(T... values) {
        return values;
    }

    @Override
    public int getOrder() {
        return HIGHEST_PRECEDENCE;
    }
}

跟 DubboConfigConfiguration.Single：

@EnableDubboConfigBindings({
    @EnableDubboConfigBinding(prefix = "dubbo.application", type = ApplicationConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.module", type = ModuleConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.registry", type = RegistryConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.protocol", type = ProtocolConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.monitor", type = MonitorConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.provider", type = ProviderConfig.class),
    @EnableDubboConfigBinding(prefix = "dubbo.consumer", type = ConsumerConfig.class)
})
public static class Single {

}

@DubboComponentScan

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(DubboComponentScanRegistrar.class)
public @interface DubboComponentScan {

    String[] value() default {};
    String[] basePackages() default {};
    Class<?>[] basePackageClasses() default {};
}

类 DubboComponentScanRegistrar

@Override
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
	//处理@DubboComponentScan的basePackages basePackageClasses value属性
	//返回所有要扫描的包名
    Set<String> packagesToScan = getPackagesToScan(importingClassMetadata);
	//注册能处理@Service的BeanPostProcessor
    registerServiceAnnotationBeanPostProcessor(packagesToScan, registry);
	//注册能处理@Reference的BeanPostProcessor
    registerReferenceAnnotationBeanPostProcessor(registry);

}