springboot源码从main函数开始
public static void main(String[] args) {
ApplicationContext app = SpringApplication.run(BeikbankApplication.class, args);
}
进入run方法,再持续进入到实际操作的步骤
public static ConfigurableApplicationContext run(Object source, String... args) {
return run(new Object[] { source }, args);
}
public static ConfigurableApplicationContext run(Object[] sources, String[] args) {
return new SpringApplication(sources).run(args);
}
public ConfigurableApplicationContext run(String... args) {
//秒表计时器,用来记录整个容器启动时间
StopWatch stopWatch = new StopWatch();
stopWatch.start();
ConfigurableApplicationContext context = null;
FailureAnalyzers analyzers = null;
//配置headless系统属性
configureHeadlessProperty();
//获取springbootApplication注解的类信息开启监听
SpringApplicationRunListeners listeners = getRunListeners(args);
listeners.starting();
try {
//应用参数初始化
ApplicationArguments applicationArguments = new DefaultApplicationArguments(
args);
//环境变量初始化
ConfigurableEnvironment environment = prepareEnvironment(listeners,
applicationArguments);
//打印banner,就是spring图形
Banner printedBanner = printBanner(environment);
//创建应用上下文,默认会得到AnnotationConfigEmbeddedWebApplicationContext
context = createApplicationContext();
//反射加载实例化FailureAnalyzer实现类
analyzers = new FailureAnalyzers(context);
//上下文环境准备
prepareContext(context, environment, listeners, applicationArguments,
printedBanner);
//主要的IOC过程,也是springMVC的主要过程,进行bean的相关接口初始化和bean实例化
refreshContext(context);
//到上一步tomcat已经启动完成了,这里算是springboot的扩展接口,可以自己实现ApplicationRunner或CommandLineRunner接口,在这里进行实例化开始运行
afterRefresh(context, applicationArguments);
//发布事件监听器
listeners.finished(context, null);
//停止计时
stopWatch.stop();
if (this.logStartupInfo) {
new StartupInfoLogger(this.mainApplicationClass)
.logStarted(getApplicationLog(), stopWatch);
}
return context;
}
catch (Throwable ex) {
handleRunFailure(context, listeners, analyzers, ex);
throw new IllegalStateException(ex);
}
}
我把主要步骤的每一步都标明了注释,看起来这里很多都是springboot特有,但主要的实现还是对springMVC的继承,你去看springmvc的源码,会发现,它主要的过程就是refreshContext这个方法所展现的过程