上一篇：SpringBoot 动态代理|反射|注解|AOP 优化代码(三)-注解
本篇我们将实现通过代理生成的对象注入到spring容器中。
首先需要实现BeanDefinitionRegistryPostProcessor, ApplicationContextAware两个接口，作用分别为：
ApplicationContextAware：可以获得ApplicationContext对象，然后获取Spring容器中的对象
BeanDefinitionRegistryPostProcessor：可以将我们自定义的bean注入到spring容器
@Slf4j@Componentpublic class HandlerBeanDefinitionRegistry implements BeanDefinitionRegistryPostProcessor, ApplicationContextAware { private ApplicationContext applicationContext; @Override public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException { /** * 获取AutoImpl注解的接口，这些接口就需要通过动态代理提供默认实现 */ Set<Class<?>> classes = getAutoImplClasses(); for (Class<?> clazz : classes) { /** * 获取继承自HandlerRouter的接口的泛型的类型typeName，传入到DynamicProxyBeanFactory * 以便传入到DynamicProxyBeanFactory扫描typeName的实现类，然后按照feign和url两种实现 * 方式分类 */ Type[] types = clazz.getGenericInterfaces(); ParameterizedType type = (ParameterizedType) types[0]; String typeName = type.getActualTypeArguments()[0].getTypeName(); /** * 通过FactoryBean注入到spring容器，HandlerInterfaceFactoryBean实现以下功能： * 1.调用动态代理DynamicProxyBeanFactory提供HandlerRouter子接口的默认实现 * 2.将第一步的默认实现，注入到spring容器 */ HandlerRouterAutoImpl handlerRouterAutoImpl = clazz.getAnnotation(HandlerRouterAutoImpl.class); BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(clazz); GenericBeanDefinition definition = (GenericBeanDefinition) builder.getRawBeanDefinition(); definition.getPropertyValues().add("interfaceClass", clazz); definition.getPropertyValues().add("typeName", typeName); definition.getPropertyValues().add("context", applicationContext); definition.setBeanClass(HandlerInterfaceFactoryBean.class); definition.setAutowireMode(GenericBeanDefinition.AUTOWIRE_BY_TYPE); beanDefinitionRegistry.registerBeanDefinition(handlerRouterAutoImpl.name(), definition); } } @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException { log.info("------------------------>postProcessBeanFactory"); } /** * 通过反射扫描出所有使用HandlerRouterAutoImpl的类 * @return */ private Set<Class<?>> getAutoImplClasses() { Reflections reflections = new Reflections( "io.ubt.iot.devicemanager.impl.handler.*", new TypeAnnotationsScanner(), new SubTypesScanner() ); return reflections.getTypesAnnotatedWith(HandlerRouterAutoImpl.class); } @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; log.info("------------------->setApplicationContext"); } /** * 通过class获取所有该类型的bean * * @param clazz * @return */ private Map<String, T> getBeans(Class<T> clazz) { return applicationContext.getBeansOfType(clazz); } private String getYmlProperty(String propery) { return applicationContext.getEnvironment().getProperty(propery); }}HandlerInterfaceFactoryBean 通过动态代理创建默认实现类
@Slf4j@Datapublic class HandlerInterfaceFactoryBean<T> implements FactoryBean<T> { private Class<T> interfaceClass; private String typeName; private ApplicationContext context; @Override public T getObject() throws Exception { Object object = DynamicProxyBeanFactory.newMapperProxy(typeName, context, interfaceClass); return (T) object; } @Override public Class<?> getObjectType() { return interfaceClass; } @Override public boolean isSingleton() { return true; }}DynamicProxyBeanFactory 最终实现
@Slf4jpublic class DynamicProxyBeanFactory implements InvocationHandler { private String className; private ApplicationContext applicationContext; private Map<ClientType, Object> clientMap = new HashMap<>(2); public DynamicProxyBeanFactory(String className, ApplicationContext applicationContext) { this.className = className; this.applicationContext = applicationContext; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { if (clientMap.size() == 0) { initClientMap(); } Integer env = (Integer) args[0]; return 1 == env.intValue() ? clientMap.get(ClientType.FEIGN) : clientMap.get(ClientType.URL); } private void initClientMap() throws ClassNotFoundException { //获取classStr 接口的所有实现类 Map<String,?> classMap = applicationContext.getBeansOfType(Class.forName(className)); log.info("DynamicProxyBeanFactory className:{} impl class:{}",className,classMap); for (Map.Entry<String,?> entry : classMap.entrySet()) { //根据ApiClientType注解将实现类分为Feign和Url两种类型 ApiClient apiClient = entry.getValue().getClass().getAnnotation(ApiClient.class); if (apiClient == null) { continue; } clientMap.put(apiClient.type(), entry.getValue()); } log.info("DynamicProxyBeanFactory clientMap:{}",clientMap); } public static <T> T newMapperProxy(String classStr,ApplicationContext applicationContext,Class<T> mapperInterface) { ClassLoader classLoader = mapperInterface.getClassLoader(); Class<?>[] interfaces = new Class[]{mapperInterface}; DynamicProxyBeanFactory proxy = new DynamicProxyBeanFactory(classStr,applicationContext); return (T) Proxy.newProxyInstance(classLoader, interfaces, proxy); }}以上便是注解获取目标类，动态代理提供默认实现，并注入到Spring容器的核心代码。
单元测试
@Slf4j@SpringBootTest@RunWith(SpringRunner.class)public class OptimizationTest { @Autowired @Qualifier("deviceHandlerRouter") private DeviceHandlerRouter deviceHandlerRouter; @Test public void dispatchApp() { DeviceHandler deviceHandlerFeignImpl = deviceHandlerRouter.getHandler(1, null); log.info("DeviceHandler-------------->{}",deviceHandlerFeignImpl); DeviceHandler deviceHandlerUrlImpl = deviceHandlerRouter.getHandler(2, null); log.info("DeviceHandler-------------->{}",deviceHandlerUrlImpl); } }Aop优化代码待续
参考文章https://blog.csdn.net/qq_2059...