springboot-内置tomcat

跟踪springboot自启动tomcat

    工作需要修改内置tomcat连接参数，将自己分析前后分享。​   springboot 内置tomcat，tomcat为自动开启的配置，进入@SpringBootApplication注解。

//@SpringBootApplication注解源码@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@SpringBootConfiguration@EnableAutoConfiguration    //开启自启动程序@ComponentScan(excludeFilters = {      @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),      @Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })public @interface SpringBootApplication {

//@EnableAutoConfiguration 注解源码@SuppressWarnings("deprecation")@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@AutoConfigurationPackage@Import(EnableAutoConfigurationImportSelector.class) //加载需要自启动的配置文件public @interface EnableAutoConfiguration {

​   springboot原理，就是使用SpingFactoriesLoader.loadFactoryNames 扫描具有META-INFO/spring.factories文件的jar包 。​   加载容器的配置文件 EmbeddedServletContainerAutoConfiguration,在配置文件中，内置tomcat（满足tomcat容器条件的bean存在），只要满足Jetty、Undertow的条件，可以切换为其他容器。

//EmbeddedServletContainerAutoConfiguration 源码@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)@Configuration@ConditionalOnWebApplication@Import(BeanPostProcessorsRegistrar.class)public class EmbeddedServletContainerAutoConfiguration {   /**    * Nested configuration if Tomcat is being used.    */   @Configuration       //tomcat启动条件（springboot内置存在）   @ConditionalOnClass({ Servlet.class, Tomcat.class })     @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class, search = SearchStrategy.CURRENT)   public static class EmbeddedTomcat {      @Bean      public TomcatEmbeddedServletContainerFactory tomcatEmbeddedServletContainerFactory() {         return new TomcatEmbeddedServletContainerFactory();      }   }   /**    * Nested configuration if Jetty is being used.    */   @Configuration     //jetty启动条件 ：导入相应的pom文件即可   @ConditionalOnClass({ Servlet.class, Server.class, Loader.class,         WebAppContext.class })      @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class, search = SearchStrategy.CURRENT)   public static class EmbeddedJetty {      @Bean      public JettyEmbeddedServletContainerFactory jettyEmbeddedServletContainerFactory() {         return new JettyEmbeddedServletContainerFactory();      }   }   /**    * Nested configuration if Undertow is being used.    */   @Configuration     //Undertow 启动条件   @ConditionalOnClass({ Servlet.class, Undertow.class, SslClientAuthMode.class })   @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class, search = SearchStrategy.CURRENT)   public static class EmbeddedUndertow {      @Bean      public UndertowEmbeddedServletContainerFactory undertowEmbeddedServletContainerFactory() {         return new UndertowEmbeddedServletContainerFactory();      }   }

​   以tomcat为例，继续看如何加载并配置servlet容器       TomcatEmbeddedServletContainerFactory 获取容器

@Overridepublic EmbeddedServletContainer getEmbeddedServletContainer(      ServletContextInitializer... initializers) {   Tomcat tomcat = new Tomcat();   File baseDir = (this.baseDirectory != null ? this.baseDirectory         : createTempDir("tomcat"));   tomcat.setBaseDir(baseDir.getAbsolutePath());  //通过nio1连接 org.apache.coyote.http11.Http11NioProtocol   Connector connector = new Connector(this.protocol);     tomcat.getService().addConnector(connector);   customizeConnector(connector);  //connector 个性化配置  //模板设计模式   tomcat.setConnector(connector);   tomcat.getHost().setAutoDeploy(false);   configureEngine(tomcat.getEngine());   for (Connector additionalConnector : this.additionalTomcatConnectors) {      tomcat.getService().addConnector(additionalConnector);   }   prepareContext(tomcat.getHost(), initializers);   return getTomcatEmbeddedServletContainer(tomcat);}

​   继续跟踪查看customizeConnector(connector);   ​   查看此方法源码 所以有两种方式可以实现个性化的connector​   1.继承 TomcatEmbeddedServletContainerFactory 重写此方法，加入个性化配置​   2.实现TomcatConnectorCustomizer 接口，将实现类加入到TomcatEmbeddedServletContainerFactory 

for (TomcatConnectorCustomizer customizer : this.tomcatConnectorCustomizers) {   customizer.customize(connector);  //个性化配置的主要接口}

//添加个性化connector类  TomcatConnectorCustomizerpublic void addConnectorCustomizers(      TomcatConnectorCustomizer... tomcatConnectorCustomizers) {   Assert.notNull(tomcatConnectorCustomizers,         "TomcatConnectorCustomizers must not be null");   this.tomcatConnectorCustomizers.addAll(Arrays.asList(tomcatConnectorCustomizers));}  

​   TomcatConnectorCustomizer  自定义个性化connector（实现此类后，将实现类接入到factory中即可）

public interface TomcatConnectorCustomizer {   /**    * Customize the connector.    * @param connector the connector to customize    */   void customize(Connector connector);}