关于springboot:81SpringBoot启动流程把spring应用跑起来

刷新 IOC 容器 refreshContext

private void refreshContext(ConfigurableApplicationContext context) {if (this.registerShutdownHook) {
            try {context.registerShutdownHook();
            }
            catch (AccessControlException ex) {// Not allowed in some environments.}
        }
        //spring 的外围源码
        refresh((ApplicationContext) context);
    }

============== 进入 refresh((ApplicationContext) context);
@Deprecated
protected void refresh(ApplicationContext applicationContext) {Assert.isInstanceOf(ConfigurableApplicationContext.class, applicationContext);
        refresh((ConfigurableApplicationContext) applicationContext);
    }

protected void refresh(ConfigurableApplicationContext applicationContext) {applicationContext.refresh();
}

@Override
public final void refresh() throws BeansException, IllegalStateException {
        try {super.refresh();
        }
        catch (RuntimeException ex) {
            WebServer webServer = this.webServer;
            if (webServer != null) {webServer.stop();
            }
            throw ex;
        }
}

//spring ioc 容器的经典的初始化过程
public void refresh() throws BeansException, IllegalStateException {
        Object var1 = this.startupShutdownMonitor;
        synchronized(this.startupShutdownMonitor) {StartupStep contextRefresh = this.applicationStartup.start("spring.context.refresh");
            this.prepareRefresh();
            ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();
            this.prepareBeanFactory(beanFactory);

            try {this.postProcessBeanFactory(beanFactory);
                StartupStep beanPostProcess = this.applicationStartup.start("spring.context.beans.post-process");
                this.invokeBeanFactoryPostProcessors(beanFactory);
                this.registerBeanPostProcessors(beanFactory);
                beanPostProcess.end();
                this.initMessageSource();
                this.initApplicationEventMulticaster();
                this.onRefresh();
                this.registerListeners();
                // 实例化容器中所有的组件
                this.finishBeanFactoryInitialization(beanFactory);
                this.finishRefresh();} catch (BeansException var10) {if (this.logger.isWarnEnabled()) {this.logger.warn("Exception encountered during context initialization - cancelling refresh attempt:" + var10);
                }

                this.destroyBeans();
                this.cancelRefresh(var10);
                throw var10;
            } finally {this.resetCommonCaches();
                contextRefresh.end();}

        }
    }

callRunners(context, applicationArguments)

private void callRunners(ApplicationContext context, ApplicationArguments args) {
        // 筹备 runners 汇合 
        List<Object> runners = new ArrayList<>();
//getBeansOfType：依据类型获取组件 CommandLineRunner，ApplicationRunner    
        runners.addAll(context.getBeansOfType(ApplicationRunner.class).values());
        runners.addAll(context.getBeansOfType(CommandLineRunner.class).values());
        // 合并所有 runner 并且依照 @Order 进行排序
        AnnotationAwareOrderComparator.sort(runners);
        // 遍历遍历所有的 runner。调用各自的 run 办法
        for (Object runner : new LinkedHashSet<>(runners)) {if (runner instanceof ApplicationRunner) {callRunner((ApplicationRunner) runner, args);
            }
            if (runner instanceof CommandLineRunner) {callRunner((CommandLineRunner) runner, args);
            }
        }
    }

@FunctionalInterface
public interface ApplicationRunner {

    /**
     * Callback used to run the bean.
     * @param args incoming application arguments
     * @throws Exception on error
     */
    void run(ApplicationArguments args) throws Exception;

}

@FunctionalInterface
public interface CommandLineRunner {

    /**
     * Callback used to run the bean.
     * @param args incoming main method arguments
     * @throws Exception on error
     */
    void run(String... args) throws Exception;

}

handleRunFailure(context, ex, listeners);

private void handleRunFailure(ConfigurableApplicationContext context, Throwable exception,
            SpringApplicationRunListeners listeners) {
        try {
            try {handleExitCode(context, exception);
                if (listeners != null) {// 调用 listeners.failed(context, exception);
                    listeners.failed(context, exception);
                }
            }
            finally {reportFailure(getExceptionReporters(context), exception);
                if (context != null) {context.close();
                }
            }
        }
        catch (Exception ex) {logger.warn("Unable to close ApplicationContext", ex);
        }
        ReflectionUtils.rethrowRuntimeException(exception);
    }

// 如果有异样，持续捕捉异样
handleRunFailure(context, ex, null);

private void handleRunFailure(ConfigurableApplicationContext context, Throwable exception,
            SpringApplicationRunListeners listeners) {
        try {
            try {handleExitCode(context, exception);
                if (listeners != null) {
//running 如果有问题。持续告诉 failed。// 调用所有 Listener 的 failed；告诉所有的监听器 failed 以后我的项目运行失败
                    listeners.failed(context, exception);
                }
            }
            finally {reportFailure(getExceptionReporters(context), exception);
                if (context != null) {context.close();
                }
            }
        }
        catch (Exception ex) {logger.warn("Unable to close ApplicationContext", ex);
        }
        ReflectionUtils.rethrowRuntimeException(exception);
    }