SpringBoot 动态代理|反射|注解（四）- 动态代理对象注入到Spring容器

摘要：上一篇动态代理反射注解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容器中。单元测试优化代码待续参考文章

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+ FactoryBean：可以将我们自定义的bean注入到spring容器

@Slf4j
@Component
public 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> 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> 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 getBeans(Class 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
@Data
public class HandlerInterfaceFactoryBean implements FactoryBean {
    private Class 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

@Slf4j
public class DynamicProxyBeanFactory implements InvocationHandler {

    private String className;
    private ApplicationContext applicationContext;

    private Map 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 classMap = applicationContext.getBeansOfType(Class.forName(className));
        log.info("DynamicProxyBeanFactory className:{} impl class:{}",className,classMap);

        for (Map.Entry 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 newMapperProxy(String classStr,ApplicationContext applicationContext,Class 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。

@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...