public class PackAnnotationApplicationContext extends GenericWebApplicationContext {


  public PackAnnotationApplicationContext() {
    AnnotationConfigUtils.registerAnnotationConfigProcessors(this);
  }


  @Override
  protected void onRefresh() {
    super.onRefresh();
    try {
      // 創(chuàng)建WebServer
      createWebServer() ;
    } catch (Exception e) {
      throw new ApplicationContextException("Unable to start web server", e) ;
    }
  }


  @Override
  protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
    beanFactory.addBeanPostProcessor(new PackServletContextAwareProcessor(this)) ;
    super.postProcessBeanFactory(beanFactory);
  }


  private void createWebServer() throws Exception {
    final int PORT = 8088 ;


    Tomcat tomcat = new Tomcat() ;
    // 獲取Server節(jié)點(diǎn) ---》 server.xml 【Server節(jié)點(diǎn)】
    Server server = tomcat.getServer() ;
    // 獲取Service節(jié)點(diǎn) ---》 server.xml 【Server---> Service節(jié)點(diǎn)】
    Service service = server.findService("Tomcat") ;


    // 配置Connector ---》 server.xml 【Server---> Service--->Connector節(jié)點(diǎn)】
    Http11NioProtocol protocol = new Http11NioProtocol() ;
    ThreadPoolExecutor executor = new ThreadPoolExecutor(1, 1, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<>()) ;
    // 配置Connector ---》 server.xml 【Server---> Service--->Executor節(jié)點(diǎn)】
    protocol.setExecutor(executor) ;
    protocol.setConnectionTimeout(20000);
    Connector connector = new Connector(protocol) ;
    // 設(shè)置訪問(wèn)端口
    connector.setPort(PORT) ;
    connector.setURIEncoding("UTF-8") ;
    service.addConnector(connector) ;


    // 配置Engine ---》 server.xml 【Server--->Service--->Engine】
    StandardEngine engine = new StandardEngine() ;
    // 這里的設(shè)置的默認(rèn)host要和下面StandardHost設(shè)置的name一致
    engine.setDefaultHost("localhost");
    // 配置Engine ---》 server.xml 【Server--->Service--->Engine--->Host】
    StandardHost host = new StandardHost() ;
    host.setName("localhost") ;
    host.setAppBase(System.getProperties().getProperty("user.home")) ;
    engine.addChild(host) ;
    service.setContainer(engine) ;


    // 配置Context ---》 server.xml 【Server--->Service--->Engine--->Host--->Context】
    StandardContext context = new StandardContext() ;
    // 如果不配置這個(gè)，則會(huì)有這個(gè)錯(cuò)誤：One or more components marked the context as not correctly configured
    context.addLifecycleListener(new FixContextListener()) ;
    // 訪問(wèn)路徑
    context.setPath("");
    // Context節(jié)點(diǎn)添加到Host節(jié)點(diǎn)
    host.addChild(context) ;


    context.addServletContainerInitializer(new ServletContainerInitializer() {
      @Override
      public void onStartup(Set<Class<?>> c, ServletContext servletContext) throws ServletException {
        // 這個(gè)的主要作用是，當(dāng)一個(gè)Bean實(shí)現(xiàn)了ServletContextAware接口時(shí)，用來(lái)注入該ServletContext對(duì)象
        PackAnnotationApplicationContext.this.setServletContext(servletContext) ;
        DispatcherServlet dispatcherServlet = PackAnnotationApplicationContext.this.getBean(DispatcherServlet.class) ;
        Dynamic dynamic = servletContext.addServlet("dispatcherServlet", dispatcherServlet) ;
        dynamic.setLoadOnStartup(0) ;
        dynamic.addMapping("/*") ;
      }
    }, null);
    tomcat.start();
  }
}

public class PackSpringApplication {


  private Class<?>[] primarySources ;


  public PackSpringApplication(Class<?>[] primarySources) {
    this.primarySources = primarySources ;
  }


  public ConfigurableApplicationContext run(String[] args) {
    ConfigurableApplicationContext context =  new PackAnnotationApplicationContext() ;
    prepareEnvironment(context, args) ;
    prepareContext(context) ;
    refreshContex(context) ;
    return context ;
  }
  // 刷新上下文，核心就是調(diào)用AbstractApplicationContext#refresh方法
  private void refreshContex(ConfigurableApplicationContext context) {
    context.refresh() ;
  }
  // 注備上下文環(huán)境，這里簡(jiǎn)單處理了命令行參數(shù)
  private void prepareEnvironment(ConfigurableApplicationContext context, String[] args) {
    ConfigurableEnvironment environment = new StandardEnvironment() ;
    PropertySource<?> propertySource = new SimpleCommandLinePropertySource(args) ;
    environment.getPropertySources().addFirst(propertySource) ;
    context.setEnvironment(environment) ;
  }
  // 準(zhǔn)備上下文
  private void prepareContext(ConfigurableApplicationContext context) {
    BeanDefinitionRegistry registry = getBeanDefinitionRegistry(context) ;
    BeanNameGenerator generator = new DefaultBeanNameGenerator() ; 
    for (Class<?> clazz : primarySources) {
      AbstractBeanDefinition definition = BeanDefinitionBuilder.genericBeanDefinition(clazz).getBeanDefinition() ;
      registry.registerBeanDefinition(generator.generateBeanName(definition, registry), definition) ;
    }
  }


  private BeanDefinitionRegistry getBeanDefinitionRegistry(ApplicationContext context) {
    if (context instanceof BeanDefinitionRegistry) {
      return (BeanDefinitionRegistry) context;
    }
    if (context instanceof AbstractApplicationContext) {
      return (BeanDefinitionRegistry) ((AbstractApplicationContext) context).getBeanFactory();
    }
    throw new IllegalStateException("Could not locate BeanDefinitionRegistry");
  }
  public static ConfigurableApplicationContext run(Class<?> primarySource, String[] args) {
    return new PackSpringApplication(new Class<?>[] {primarySource}).run(args) ;
  }
}

@Configuration
public class WebConfig {


  @Bean
  public DispatcherServlet dispatcherServlet() {
    DispatcherServlet dispatcherServlet = new DispatcherServlet();
    dispatcherServlet.setDispatchOptionsRequest(true) ;
    dispatcherServlet.setDispatchTraceRequest(true) ;
    dispatcherServlet.setThrowExceptionIfNoHandlerFound(true) ;
    dispatcherServlet.setPublishEvents(true) ;
    dispatcherServlet.setEnableLoggingRequestDetails(true) ;
    return dispatcherServlet ;
  }
}

@RestController
@RequestMapping("/demo")
public class DemoController {


  @GetMapping("/index")
  public Object index() {
    return "index......" ;
  }
  @GetMapping("/body")
  public User body() {
    return new User(1, "測(cè)試") ;
  }
}

@Configuration
@ComponentScan({"com.pack.main.programmatic_tomcat_04"})
public class DemoApplication {


  public static void main(String[] args) {
    PackSpringApplication.run(DemoApplication.class, args) ;
  }
}

@Bean
public RequestMappingHandlerAdapter requestMappingHandlerAdapter() {
  RequestMappingHandlerAdapter handlerAdapter = new RequestMappingHandlerAdapter() ;
  List<HttpMessageConverter<?>> messageConverters = new ArrayList<>() ;
  messageConverters.add(new StringHttpMessageConverter());
  messageConverters.add(new MappingJackson2HttpMessageConverter()) ;
  handlerAdapter.setMessageConverters(messageConverters) ;
  return handlerAdapter ;
}