springboot源码解析-管中窥豹系列之web服务器（七） (2)

这个类里面有一个静态类: EmbeddedTomcat

@Configuration(proxyBeanMethods = false) @ConditionalOnClass({ Servlet.class, Tomcat.class, UpgradeProtocol.class }) @ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT) static class EmbeddedTomcat { @Bean TomcatServletWebServerFactory tomcatServletWebServerFactory( ObjectProvider<TomcatConnectorCustomizer> connectorCustomizers, ObjectProvider<TomcatContextCustomizer> contextCustomizers, ObjectProvider<TomcatProtocolHandlerCustomizer<?>> protocolHandlerCustomizers) { TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory(); factory.getTomcatConnectorCustomizers() .addAll(connectorCustomizers.orderedStream().collect(Collectors.toList())); factory.getTomcatContextCustomizers() .addAll(contextCustomizers.orderedStream().collect(Collectors.toList())); factory.getTomcatProtocolHandlerCustomizers() .addAll(protocolHandlerCustomizers.orderedStream().collect(Collectors.toList())); return factory; } }

ConditionOnClass : 它依赖 Servlet.class, Tomcat.class, UpgradeProtocol.class

ConditionalOnMissingBean： 防止重复加载

至此，factory怎么加载进spring就找到了

我们多看一点，这个类ServletWebServerFactoryConfiguration还有两个静态类

@Configuration(proxyBeanMethods = false) @ConditionalOnClass({ Servlet.class, Server.class, Loader.class, WebAppContext.class }) @ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT) static class EmbeddedJetty { @Bean JettyServletWebServerFactory JettyServletWebServerFactory( ObjectProvider<JettyServerCustomizer> serverCustomizers) { JettyServletWebServerFactory factory = new JettyServletWebServerFactory(); factory.getServerCustomizers().addAll(serverCustomizers.orderedStream().collect(Collectors.toList())); return factory; } } @Configuration(proxyBeanMethods = false) @ConditionalOnClass({ Servlet.class, Undertow.class, SslClientAuthMode.class }) @ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT) static class EmbeddedUndertow { @Bean UndertowServletWebServerFactory undertowServletWebServerFactory( ObjectProvider<UndertowDeploymentInfoCustomizer> deploymentInfoCustomizers, ObjectProvider<UndertowBuilderCustomizer> builderCustomizers) { UndertowServletWebServerFactory factory = new UndertowServletWebServerFactory(); factory.getDeploymentInfoCustomizers() .addAll(deploymentInfoCustomizers.orderedStream().collect(Collectors.toList())); factory.getBuilderCustomizers().addAll(builderCustomizers.orderedStream().collect(Collectors.toList())); return factory; } }

一个是生成jetty服务器工厂，一个是生成undertow服务器工厂

它们的加载，取决于依赖的class是否存在

tomcat: Servlet.class, Tomcat.class, UpgradeProtocol.class

jetty: Servlet.class, Server.class, Loader.class, WebAppContext.class

undertow: Servlet.class, Undertow.class, SslClientAuthMode.class

假如我们想换成undertow服务器，依赖改了就行了

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-undertow</artifactId> </dependency>

假如我们想换成jetty服务器，同理

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jetty</artifactId> </dependency>

思维拉回来，工厂有了，我们看看工厂怎么生成的webServer

TomcatServletWebServerFactory.java @Override public WebServer getWebServer(ServletContextInitializer... initializers) { if (this.disableMBeanRegistry) { Registry.disableRegistry(); } Tomcat tomcat = new Tomcat(); File baseDir = (this.baseDirectory != null) ? this.baseDirectory : createTempDir("tomcat"); tomcat.setBaseDir(baseDir.getAbsolutePath()); Connector connector = new Connector(this.protocol); connector.setThrowOnFailure(true); tomcat.getService().addConnector(connector); customizeConnector(connector); tomcat.setConnector(connector); tomcat.getHost().setAutoDeploy(false); configureEngine(tomcat.getEngine()); for (Connector additionalConnector : this.additionalTomcatConnectors) { tomcat.getService().addConnector(additionalConnector); } prepareContext(tomcat.getHost(), initializers); return getTomcatWebServer(tomcat); }

这个方法我们就不分析了，就是生成tomcat服务器，和spring关联不大，改天我们专门分析tomcat源码

至此，整个springboot的加载web服务器过程就完了