使用其他Servlet容器
-Jetty（长连接）
-Undertow（不支持jsp）
替换为其他嵌入式Servlet容器
默认支持：
Tomcat（默认使用）
Jetty：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency> <!--引入其他的Servlet -->
<dependency>
<artifactId>spring‐boot‐starter‐jetty</artifactId>
<groupId>org.springframework.boot</groupId>
</dependency>
Undertow：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency> <!--引入其他的Servlet -->
<dependency>
<artifactId>spring‐boot‐starter‐undertow<</artifactId>
<groupId>org.springframework.boot</groupId>
</dependency>
右键排除依赖
嵌入式Servlet配置原理：
Servelt容器的自动配置类
@Configuration
@ConditionalOnWebApplication
@EnableConfigurationProperties({ServerProperties.class})
public class EmbeddedWebServerFactoryCustomizerAutoConfiguration {
public EmbeddedWebServerFactoryCustomizerAutoConfiguration() {
} @Configuration
@ConditionalOnClass({HttpServer.class})
public static class NettyWebServerFactoryCustomizerConfiguration {
public NettyWebServerFactoryCustomizerConfiguration() {
} @Bean
public NettyWebServerFactoryCustomizer nettyWebServerFactoryCustomizer(Environment environment, ServerProperties serverProperties) {
return new NettyWebServerFactoryCustomizer(environment, serverProperties);
}
} @Configuration
@ConditionalOnClass({Undertow.class, SslClientAuthMode.class})
public static class UndertowWebServerFactoryCustomizerConfiguration {
public UndertowWebServerFactoryCustomizerConfiguration() {
} @Bean
public UndertowWebServerFactoryCustomizer undertowWebServerFactoryCustomizer(Environment environment, ServerProperties serverProperties) {
return new UndertowWebServerFactoryCustomizer(environment, serverProperties);
}
} @Configuration
@ConditionalOnClass({Server.class, Loader.class, WebAppContext.class})
public static class JettyWebServerFactoryCustomizerConfiguration {
public JettyWebServerFactoryCustomizerConfiguration() {
} @Bean
public JettyWebServerFactoryCustomizer jettyWebServerFactoryCustomizer(Environment environment, ServerProperties serverProperties) {
return new JettyWebServerFactoryCustomizer(environment, serverProperties);
}
} @Configuration
@ConditionalOnClass({Tomcat.class, UpgradeProtocol.class})
public static class TomcatWebServerFactoryCustomizerConfiguration {
public TomcatWebServerFactoryCustomizerConfiguration() {
} @Bean
public TomcatWebServerFactoryCustomizer tomcatWebServerFactoryCustomizer(Environment environment, ServerProperties serverProperties) {
return new TomcatWebServerFactoryCustomizer(environment, serverProperties);
}
}
}
Tomcat 的Server的定制（Jetty、Netty、Undertow 类似）
TomcatWebServerFactoryCustomizer.java
public class TomcatWebServerFactoryCustomizer implements WebServerFactoryCustomizer<ConfigurableTomcatWebServerFactory>, Ordered {
private final Environment environment;
private final ServerProperties serverProperties;
public TomcatWebServerFactoryCustomizer(Environment environment, ServerProperties serverProperties) {
this.environment = environment;
this.serverProperties = serverProperties;
}
public int getOrder() {
return ;
}
public void customize(ConfigurableTomcatWebServerFactory factory) {
ServerProperties properties = this.serverProperties;
Tomcat tomcatProperties = properties.getTomcat();
PropertyMapper propertyMapper = PropertyMapper.get();
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getBasedir).whenNonNull().to(factory::setBaseDirectory);
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getBackgroundProcessorDelay).whenNonNull().as(Duration::getSeconds).as(Long::intValue).to(factory::setBackgroundProcessorDelay);
this.customizeRemoteIpValve(factory);
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getMaxThreads).when(this::isPositive).to((maxThreads) -> {
this.customizeMaxThreads(factory, tomcatProperties.getMaxThreads());
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getMinSpareThreads).when(this::isPositive).to((minSpareThreads) -> {
this.customi*Threads(factory, minSpareThreads);
});
propertyMapper.from(this::determineMaxHttpHeaderSize).whenNonNull().asInt(DataSize::toBytes).when(this::isPositive).to((maxHttpHeaderSize) -> {
this.customizeMaxHttpHeaderSize(factory, maxHttpHeaderSize);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getMaxSwallowSize).whenNonNull().asInt(DataSize::toBytes).to((maxSwallowSize) -> {
this.customizeMaxSwallowSize(factory, maxSwallowSize);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getMaxHttpPostSize).asInt(DataSize::toBytes).when((maxHttpPostSize) -> {
return maxHttpPostSize != ;
}).to((maxHttpPostSize) -> {
this.customizeMaxHttpPostSize(factory, maxHttpPostSize);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getAccesslog).when(Accesslog::isEnabled).to((enabled) -> {
this.customizeAccessLog(factory);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getUriEncoding).whenNonNull().to(factory::setUriEncoding);
properties.getClass();
propertyMapper.from(properties::getConnectionTimeout).whenNonNull().to((connectionTimeout) -> {
this.customizeConnectionTimeout(factory, connectionTimeout);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getMaxConnections).when(this::isPositive).to((maxConnections) -> {
this.customizeMaxConnections(factory, maxConnections);
});
tomcatProperties.getClass();
propertyMapper.from(tomcatProperties::getAcceptCount).when(this::isPositive).to((acceptCount) -> {
this.customizeAcceptCount(factory, acceptCount);
});
this.customizeStaticResources(factory);
this.customizeErrorReportValve(properties.getError(), factory);
}
.......
}
步骤：
1）、SpringBoot根据导入的依赖情况，给容器中添加相应的
EmbeddedServletContainerFactory【TomcatEmbeddedServletContainerFactory】
2）、容器中某个组件要创建对象就会惊动后置处理器；
EmbeddedServletContainerCustomizerBeanPostPro
只要是嵌入式的Servlet容器工厂，后置处理器就工作；
3）、后置处理器，从容器中获取所有的EmbeddedServletContainerCustomizer，调
用定制器的定制方法
嵌入式Servlet容器启动原理；
什么时候创建嵌入式的Servlet容器工厂？什么时候获取嵌入式的Servlet容器并启动Tomcat；
获取嵌入式的Servlet容器工厂：
断点
1）、SpringBoot应用启动运行run
2）、refreshContext(context);SpringBoot刷新IOC容器【创建IOC容器对象，并初始化容器
创建容器中的每一个组件】
3）、refresh(context);刷新刚才创建好的ioc容器
private void refreshContext(ConfigurableApplicationContext context) {
this.refresh(context);
if (this.registerShutdownHook) {
try {
context.registerShutdownHook();
} catch (AccessControlException var3) {
;
}
}
}
4）、 onRefresh(); web的ioc容器重写了onRefresh方法
5）、webioc容器会创建嵌入式的Servlet容器；ServletWebServerApplicationContext(
6）、获取嵌入式的Servlet容器工厂
7）、使用容器工厂获取嵌入式的Servlet容器
8）、嵌入式的Servlet容器创建对象并启动Servlet容
先启动嵌入式的Servlet容器，再将ioc容器中剩下没有创建出的对象获取出来；
IOC容器启动创建嵌入式的Servlet容器