@SpringBootApplcation
public static void main(String[] args) {
    SpringApplication.run(BlogAdminApplication.class, args);
    System.out.println("======== admin start success... ==========");
}

public static ConfigurableApplicationContext run(Class<?> primarySource, String... args) {
    return run(new Class[]{primarySource}, args);
}

@SpringBootApplication
public class BlogProjectApplication {
   public static void main(String[] args) {
       SpringApplication.run(ManagerController.class, args);
       System.out.println("======== admin start success... ==========");
   }
}

@FunctionalInterface
public interface ServletWebServerFactory {
    WebServer getWebServer(ServletContextInitializer... initializers);
}

省略。。。
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\
org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\
org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\
org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\
省略。。。

@RestController
@RequestMapping("project/manager")
@EnableAutoConfiguration
public class ManagerController extends AbstractController {

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
//
@ComponentScan(
    excludeFilters = {@Filter(
    type = FilterType.CUSTOM,
    classes = {TypeExcludeFilter.class}
), @Filter(
    type = FilterType.CUSTOM,
    classes = {AutoConfigurationExcludeFilter.class}
)}
)
public @interface SpringBootApplication {

public static ConfigurableApplicationContext run(Class<?>[] primarySources, String[] args) {
    return (new SpringApplication(primarySources)).run(args);
}

public SpringApplication(Class<?>... primarySources) {
    this((ResourceLoader)null, primarySources);
}
public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
    //資源加載器
   this.resourceLoader = resourceLoader;
   //斷言
   Assert.notNull(primarySources, "PrimarySources must not be null");
   //對(duì)primarySources進(jìn)行存儲(chǔ)到LinkedHashSet
   this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
   //1、推斷web應(yīng)用類別
   this.webApplicationType = WebApplicationType.deduceFromClasspath();
   //2、加載Spring應(yīng)用上下文初始化
   setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
   //3、加載Spring應(yīng)用事件監(jiān)聽(tīng)器
   setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
   //4、推斷應(yīng)用引導(dǎo)類
   this.mainApplicationClass = deduceMainApplicationClass();
}

this.webApplicationType = WebApplicationType.deduceFromClasspath();
private static final String[] SERVLET_INDICATOR_CLASSES = { "javax.servlet.Servlet",
      "org.springframework.web.context.ConfigurableWebApplicationContext" };
private static final String WEBMVC_INDICATOR_CLASS = "org.springframework." + "web.servlet.DispatcherServlet";
private static final String WEBFLUX_INDICATOR_CLASS = "org." + "springframework.web.reactive.DispatcherHandler";
private static final String JERSEY_INDICATOR_CLASS = "org.glassfish.jersey.servlet.ServletContainer";
private static final String SERVLET_APPLICATION_CONTEXT_CLASS = "org.springframework.web.context.WebApplicationContext";
private static final String REACTIVE_APPLICATION_CONTEXT_CLASS = "org.springframework.boot.web.reactive.context.ReactiveWebApplicationContext";
static WebApplicationType deduceFromClasspath() {
//當(dāng)DispatcherHandler存在，且DispatcherServlet、ServletContainer兩個(gè)不存在時(shí)；換言之，SpringBoot僅依賴WebFlux存在時(shí)，此時(shí)的應(yīng)用類型為REACTIVE
   if (ClassUtils.isPresent(WEBFLUX_INDICATOR_CLASS, null) && !ClassUtils.isPresent(WEBMVC_INDICATOR_CLASS, null)
         && !ClassUtils.isPresent(JERSEY_INDICATOR_CLASS, null)) {
      return WebApplicationType.REACTIVE;
   }
   //當(dāng)Servlet和ConfigurableWebApplicationContext均不存在時(shí)，當(dāng)前應(yīng)用為非Web應(yīng)用，即WebApplicationType.NONE，因?yàn)檫@些API均是Spring Web MVC必須的依賴
   for (String className : SERVLET_INDICATOR_CLASSES) {
      if (!ClassUtils.isPresent(className, null)) {
         return WebApplicationType.NONE;
      }
   }
   //當(dāng)WebFlux和Spring Web MVC同時(shí)存在時(shí)，Web應(yīng)用類型同樣是Servlet Web，即WebApplicationType.SERVLET
   return WebApplicationType.SERVLET;
}

setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));

private <T> Collection<T> getSpringFactoriesInstances(Class<T> type) {
   return getSpringFactoriesInstances(type, new Class<?>[] {});
}
private <T> Collection<T> getSpringFactoriesInstances(Class<T> type, Class<?>[] parameterTypes, Object... args) {
   //獲取類加載器
   ClassLoader classLoader = getClassLoader();
   // Use names and ensure unique to protect against duplicates
   //加載了META-INF/spring.factories資源中配置的ApplicationContextInitializer實(shí)現(xiàn)類名單。
   Set<String> names = new LinkedHashSet<>(SpringFactoriesLoader.loadFactoryNames(type, classLoader));
   //初始化
   List<T> instances = createSpringFactoriesInstances(type, parameterTypes, classLoader, args, names);
   AnnotationAwareOrderComparator.sort(instances);
   return instances;
}

private <T> List<T> createSpringFactoriesInstances(Class<T> type, Class<?>[] parameterTypes,
      ClassLoader classLoader, Object[] args, Set<String> names) {
   List<T> instances = new ArrayList<>(names.size());
   for (String name : names) {
      try {
      //從類加載器中獲取指定類
         Class<?> instanceClass = ClassUtils.forName(name, classLoader);
         //判斷instanceClass是不是type的子類
         Assert.isAssignable(type, instanceClass);
         //根據(jù)以上獲取的類名創(chuàng)建類的實(shí)例
         Constructor<?> constructor = instanceClass.getDeclaredConstructor(parameterTypes);
         //排序
         T instance = (T) BeanUtils.instantiateClass(constructor, args);
         instances.add(instance);
      }
      catch (Throwable ex) {
         throw new IllegalArgumentException("Cannot instantiate " + type + " : " + name, ex);
      }
   }
   return instances;
}

setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));

public void setListeners(Collection<? extends ApplicationListener<?>> listeners) {
   this.listeners = new ArrayList<>();
   this.listeners.addAll(listeners);
}

this.mainApplicationClass = deduceMainApplicationClass(); 
private Class<?> deduceMainApplicationClass() {
  try {
     StackTraceElement[] stackTrace = new RuntimeException().getStackTrace();
     for (StackTraceElement stackTraceElement : stackTrace) {
        if ("main".equals(stackTraceElement.getMethodName())) {
           return Class.forName(stackTraceElement.getClassName());
        }
     }
  }
  catch (ClassNotFoundException ex) {
     // Swallow and continue
  }
  return null;
}

/**
 * Fills in the execution stack trace. This method records within this
 * {@code Throwable} object information about the current state of
 * the stack frames for the current thread.
 *
 * <p>If the stack trace of this {@code Throwable} {@linkplain
 * Throwable#Throwable(String, Throwable, boolean, boolean) is not
 * writable}, calling this method has no effect.
 *
 * @return  a reference to this {@code Throwable} instance.
 * @see     java.lang.Throwable#printStackTrace()
 */
public synchronized Throwable fillInStackTrace() {
    if (stackTrace != null ||
        backtrace != null /* Out of protocol state */ ) {
        fillInStackTrace(0);
        stackTrace = UNASSIGNED_STACK;
    }
    return this;
}
private native Throwable fillInStackTrace(int dummy);