Bean异步初始化，让你的应用启动飞起来

protected void invokeInitMethods(String beanName, final Object bean, @Nullable RootBeanDefinition mbd)        throws Throwable {    // 先看bean是不是实现了InitializingBean，如果是则执行afterPropertiesSet方法。    boolean isInitializingBean = (bean instanceof InitializingBean);    if (isInitializingBean && (mbd == null || !mbd.isExternallyManagedInitMethod("afterPropertiesSet"))) {        if (System.getSecurityManager() != null) {            AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () -> {                ((InitializingBean) bean).afterPropertiesSet();                return null;            }, getAccessControlContext());        } else {            ((InitializingBean) bean).afterPropertiesSet();        }    }    // xml定义的init方法    if (mbd != null && bean.getClass() != NullBean.class) {        String initMethodName = mbd.getInitMethodName();        if (StringUtils.hasLength(initMethodName) &&                !(isInitializingBean && "afterPropertiesSet".equals(initMethodName)) &&                !mbd.isExternallyManagedInitMethod(initMethodName)) {            invokeCustomInitMethod(beanName, bean, mbd);        }    }}

public class AsyncInitBeanFactory extends DefaultListableBeanFactory {
    private static final Logger logger = LoggerFactory.getLogger(AsyncInitBeanFactory.class);
    // 省略
    @Override    protected void invokeInitMethods(String beanName, Object bean, RootBeanDefinition mbd) throws Throwable {        if (AsyncInitBeanNameContainer.MIDDLEWARE_ASYNC_HSF_BEAN_NAME.contains(beanName)) {            // hsf异步init            this.asyncCallInitMethods(TaskUtil.threadPool4HsfBean, beanName, bean, mbd);        } else if (AsyncInitBeanNameContainer.MIDDLEWARE_ASYNC_INIT_BEAN_NAME.contains(beanName)) {            // 其他bean异步init            this.asyncCallInitMethods(TaskUtil.threadPool4NormalMBean, beanName, bean, mbd);        } else {            // 同步init call父类原来的invokeInitMethods            try {                super.invokeInitMethods(beanName, bean, mbd);            } catch (Exception e) {                logger.error("middleware-bean-accelerator sync-init error: {}", e.getMessage(), e);                throw e;            }        }    }    // 省略}

public class AsyncAccelerateInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext>, Ordered {
    @Override    public void initialize(ConfigurableApplicationContext context) {        // 是否开启异步初始化        if (ConfigUtil.isEnableAccelerate(context) && context instanceof GenericApplicationContext) {          AsyncInitBeanFactory beanFactory = new AsyncInitBeanFactory(context.getBeanFactory());
            // 通过反射替换beanFactory            try {                Field field = GenericApplicationContext.class.getDeclaredField("beanFactory");                field.setAccessible(true);                field.set(context, beanFactory);            } catch (Throwable e) {                throw new RuntimeException(e);            }        }    }}

@Overridepublic Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName)        throws BeansException {
    Object result = existingBean;    // 把BeanPostProcesss都抓出来调用一下    for (BeanPostProcessor processor : getBeanPostProcessors()) {        Object current = processor.postProcessBeforeInitialization(result, beanName);        if (current == null) {            return result;        }        result = current;    }    return result;}

public class AsyncCommonAnnotationBeanPostProcessor extends CommonAnnotationBeanPostProcessor {    private static final Logger logger = LoggerFactory.getLogger(AsyncCommonAnnotationBeanPostProcessor.class);
    @Override    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {        // 如果是我指定的beanName 那么走异步初始化, 把super.postProcessBeforeInitialization(bean, beanName) 放进线程池里执行        if (AsyncInitBeanNameContainer.MIDDLEWARE_ASYNC_POST_CONSTRUCT_BEAN_NAME.contains(beanName)) {            // 异步初始化            this.asyncExecutePostConstruct(bean, beanName);        } else {            // 同步初始化            return super.postProcessBeforeInitialization(bean, beanName);        }        return bean;    }    // 略}

public class OverrideAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter {
    @Override    public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {        // 替换掉原处理@PostConstruct注解的后置处理器        if ("org.springframework.context.annotation.internalCommonAnnotationProcessor".equals(beanName)) {            AsyncCommonAnnotationBeanPostProcessor asyncBeanPostProcessor = new AsyncCommonAnnotationBeanPostProcessor();            // 省略基础的设置            return asyncBeanPostProcessor;        }        return super.postProcessBeforeInstantiation(beanClass, beanName);    }}

@Servicepublic class XXXService {        @HSFConsumer(serviceVersion = "1.0.0", serviceGroup = "HSF")    private OrderService orderService;
    // 省略}

public class HsfBeanNameCollector implements BeanFactoryPostProcessor, BeanClassLoaderAware {    private ClassLoader classLoader;
    @Override    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {        // 省略        for (String beanName : beanFactory.getBeanDefinitionNames()) {            BeanDefinition definition = beanFactory.getBeanDefinition(beanName);            String beanClassName = definition.getBeanClassName();
            Class<?> clazz = ClassUtils.resolveClassName(definition.getBeanClassName(), this.classLoader);            ReflectionUtils.doWithFields(clazz, field -> {                if (AnnotationUtils.getAnnotation(field, HSFConsumer.class) == null) {                    return;                }                // 收集HsfConsumerBeanName方便后续异步化                AsyncInitStaticVariables.MIDDLEWARE_ASYNC_HSF_BEAN_NAME.add(field.getName());            });        }    }
    @Override    public void setBeanClassLoader(ClassLoader classLoader) {        this.classLoader = classLoader;    }}

public class HSFSpringConsumerBean implements FactoryBean, InitializingBean, ApplicationListener, ApplicationContextAware {    // 省略    @Override    public Object getObject() throws Exception {        return consumerBean.getObject();    }    // 省略}

public class HSFApiConsumerBean {    // 省略
    /**     * 初始化     *     * @throws Exception     */    public void init() throws Exception {        // 省略        synchronized (metadata) {            // 省略                        metadata.init();            try {                // 动态代理类的设置就在这里                metadata.setTarget(consume(metadata));              // 省略            } catch (Exception e) {                // 省略            } catch (Throwable t) {                // 省略            }
            // 省略        }    }    // 省略}

public class NewHsfSpringConsumerBean extends HSFSpringConsumerBean {    // 省略    private Future<?> initTaskFuture;
    /**     * 重写NewHsfSpringConsumerBean的主要目的 在此加入卡点 防止hsfSpringConsumerBean未初始化完成导致的npe     *     * @return     * @throws Exception     */    @Override    public Object getObject() throws Exception {        this.waitHsfInit();        return super.getObject();    }
    private void waitHsfInit() {        if (this.initTaskFuture == null) {            logger.warn("middleware-bean-accelerator, hsf getObject wait future is null.");            return;        }        try {            this.initTaskFuture.get();        } catch (InterruptedException | ExecutionException e) {            throw new RuntimeException(e);        }    }    // 省略}

public class OverrideAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter {    private final AsyncInitBeanFactory beanFactory;
    // 省略
    @Override    public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {        // 修改beanDefinition 使容器创建自定义的HsfSpringConsumerBean        if (beanClass == HSFSpringConsumerBean.class) {            this.reviseBeanDefinition(beanName, NewHsfSpringConsumerBean.class);            // 返回null可以让实例化的任务交由spring容器            return null;        }        return super.postProcessBeforeInstantiation(beanClass, beanName);    }
    @Override    public boolean postProcessAfterInstantiation(Object bean, String beanName) {        if (bean.getClass() == NewHsfSpringConsumerBean.class) {            this.reviseBeanDefinition(beanName, HSFSpringConsumerBean.class);        }        return super.postProcessAfterInstantiation(bean, beanName);    }
    /**     * 修改beanDefinition     * 设置NewHsfSpringConsumerBean使容器创建自定义的HsfSpringConsumerBean 实例化后设置回来     *     * @param beanName     * @return     */    private void reviseBeanDefinition(String beanName, Class<?> clazz) {        try {            Method methodOfRootBeanDefinition = this.beanFactory.getClass().                    getSuperclass().getSuperclass().getSuperclass().                    getDeclaredMethod("getMergedLocalBeanDefinition", String.class);            methodOfRootBeanDefinition.setAccessible(true);            RootBeanDefinition beanDefinition = (RootBeanDefinition) methodOfRootBeanDefinition.invoke(this.beanFactory, beanName);            // 重点步骤: 修改beanDefinition 使容器创建自定义的HsfSpringConsumerBean, 并在实例化后设置回来            beanDefinition.setBeanClass(clazz);        } catch (InvocationTargetException | NoSuchMethodException | IllegalAccessException e) {            throw new RuntimeException(e);        }    }}