This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Boot 3.3.4!spring-doc.cn

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Boot 3.3.4!spring-doc.cn

Each Spring Boot web application includes an embedded web server. This feature leads to a number of how-to questions, including how to change the embedded server and how to configure the embedded server. This section answers those questions.spring-doc.cn

Use Another Web Server

Many Spring Boot starters include default embedded containers.spring-doc.cn

  • For servlet stack applications, the spring-boot-starter-web includes Tomcat by including spring-boot-starter-tomcat, but you can use spring-boot-starter-jetty or spring-boot-starter-undertow instead.spring-doc.cn

  • For reactive stack applications, the spring-boot-starter-webflux includes Reactor Netty by including spring-boot-starter-reactor-netty, but you can use spring-boot-starter-tomcat, spring-boot-starter-jetty, or spring-boot-starter-undertow instead.spring-doc.cn

When switching to a different HTTP server, you need to swap the default dependencies for those that you need instead. To help with this process, Spring Boot provides a separate starter for each of the supported HTTP servers.spring-doc.cn

The following Maven example shows how to exclude Tomcat and include Jetty for Spring MVC:spring-doc.cn

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
	<exclusions>
		<!-- Exclude the Tomcat dependency -->
		<exclusion>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-tomcat</artifactId>
		</exclusion>
	</exclusions>
</dependency>
<!-- Use Jetty instead -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>

The following Gradle example configures the necessary dependencies and a module replacement to use Undertow in place of Reactor Netty for Spring WebFlux:spring-doc.cn

dependencies {
	implementation "org.springframework.boot:spring-boot-starter-undertow"
	implementation "org.springframework.boot:spring-boot-starter-webflux"
	modules {
		module("org.springframework.boot:spring-boot-starter-reactor-netty") {
			replacedBy("org.springframework.boot:spring-boot-starter-undertow", "Use Undertow instead of Reactor Netty")
		}
	}
}
spring-boot-starter-reactor-netty is required to use the WebClient class, so you may need to keep a dependency on Netty even when you need to include a different HTTP server.
spring-boot-starter-reactor-netty is required to use the WebClient class, so you may need to keep a dependency on Netty even when you need to include a different HTTP server.

Disabling the Web Server

If your classpath contains the necessary bits to start a web server, Spring Boot will automatically start it. To disable this behavior configure the WebApplicationType in your application.properties, as shown in the following example:spring-doc.cn

spring.main.web-application-type=none
spring:
  main:
    web-application-type: "none"

Change the HTTP Port

In a standalone application, the main HTTP port defaults to 8080 but can be set with server.port (for example, in application.properties or as a System property). Thanks to relaxed binding of Environment values, you can also use SERVER_PORT (for example, as an OS environment variable).spring-doc.cn

To switch off the HTTP endpoints completely but still create a WebApplicationContext, use server.port=-1 (doing so is sometimes useful for testing).spring-doc.cn

For more details, see Customizing Embedded Servlet Containers in the ‘Spring Boot Features’ section, or the ServerProperties class.spring-doc.cn

Use a Random Unassigned HTTP Port

To scan for a free port (using OS natives to prevent clashes) use server.port=0.spring-doc.cn

Discover the HTTP Port at Runtime

You can access the port the server is running on from log output or from the WebServerApplicationContext through its WebServer. The best way to get that and be sure it has been initialized is to add a @Bean of type ApplicationListener<WebServerInitializedEvent> and pull the container out of the event when it is published.spring-doc.cn

Tests that use @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) can also inject the actual port into a field by using the @LocalServerPort annotation, as shown in the following example:spring-doc.cn

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
import org.springframework.boot.test.web.server.LocalServerPort;

@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
class MyWebIntegrationTests {

	@LocalServerPort
	int port;

	// ...

}
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment
import org.springframework.boot.test.web.server.LocalServerPort

@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
class MyWebIntegrationTests {

	@LocalServerPort
	var port = 0

	// ...

}

@LocalServerPort is a meta-annotation for @Value("${local.server.port}"). Do not try to inject the port in a regular application. As we just saw, the value is set only after the container has been initialized. Contrary to a test, application code callbacks are processed early (before the value is actually available).spring-doc.cn

@LocalServerPort is a meta-annotation for @Value("${local.server.port}"). Do not try to inject the port in a regular application. As we just saw, the value is set only after the container has been initialized. Contrary to a test, application code callbacks are processed early (before the value is actually available).spring-doc.cn

Enable HTTP Response Compression

HTTP response compression is supported by Jetty, Tomcat, Reactor Netty, and Undertow. It can be enabled in application.properties, as follows:spring-doc.cn

server.compression.enabled=true
server:
  compression:
    enabled: true

By default, responses must be at least 2048 bytes in length for compression to be performed. You can configure this behavior by setting the server.compression.min-response-size property.spring-doc.cn

By default, responses are compressed only if their content type is one of the following:spring-doc.cn

You can configure this behavior by setting the server.compression.mime-types property.spring-doc.cn

Configure SSL

SSL can be configured declaratively by setting the various server.ssl.* properties, typically in application.properties or application.yaml. See Ssl for details of all of the supported properties.spring-doc.cn

The following example shows setting SSL properties using a Java KeyStore file:spring-doc.cn

server.port=8443
server.ssl.key-store=classpath:keystore.jks
server.ssl.key-store-password=secret
server.ssl.key-password=another-secret
server:
  port: 8443
  ssl:
    key-store: "classpath:keystore.jks"
    key-store-password: "secret"
    key-password: "another-secret"

Using configuration such as the preceding example means the application no longer supports a plain HTTP connector at port 8080. Spring Boot does not support the configuration of both an HTTP connector and an HTTPS connector through application.properties. If you want to have both, you need to configure one of them programmatically. We recommend using application.properties to configure HTTPS, as the HTTP connector is the easier of the two to configure programmatically.spring-doc.cn

Using PEM-encoded files

You can use PEM-encoded files instead of Java KeyStore files. You should use PKCS#8 key files wherever possible. PEM-encoded PKCS#8 key files start with a -----BEGIN PRIVATE KEY----- or -----BEGIN ENCRYPTED PRIVATE KEY----- header.spring-doc.cn

If you have files in other formats, e.g., PKCS#1 (-----BEGIN RSA PRIVATE KEY-----) or SEC 1 (-----BEGIN EC PRIVATE KEY-----), you can convert them to PKCS#8 using OpenSSL:spring-doc.cn

openssl pkcs8 -topk8 -nocrypt -in <input file> -out <output file>

The following example shows setting SSL properties using PEM-encoded certificate and private key files:spring-doc.cn

server.port=8443
server.ssl.certificate=classpath:my-cert.crt
server.ssl.certificate-private-key=classpath:my-cert.key
server.ssl.trust-certificate=classpath:ca-cert.crt
server:
  port: 8443
  ssl:
    certificate: "classpath:my-cert.crt"
    certificate-private-key: "classpath:my-cert.key"
    trust-certificate: "classpath:ca-cert.crt"

Using SSL Bundles

Alternatively, the SSL trust material can be configured in an SSL bundle and applied to the web server as shown in this example:spring-doc.cn

server.port=8443
server.ssl.bundle=example
server:
  port: 8443
  ssl:
    bundle: "example"
The server.ssl.bundle property can not be combined with the discrete Java KeyStore or PEM property options under server.ssl.

Configure Server Name Indication

Tomcat, Netty, and Undertow can be configured to use unique SSL trust material for individual host names to support Server Name Indication (SNI). SNI configuration is not supported with Jetty, but Jetty can automatically set up SNI if multiple certificates are provided to it.spring-doc.cn

Assuming SSL bundles named web, web-alt1, and web-alt2 have been configured, the following configuration can be used to assign each bundle to a host name served by the embedded web server:spring-doc.cn

server.port=8443
server.ssl.bundle=web
server.ssl.server-name-bundles[0].server-name=alt1.example.com
server.ssl.server-name-bundles[0].bundle=web-alt1
server.ssl.server-name-bundles[1].server-name=alt2.example.com
server.ssl.server-name-bundles[1].bundle=web-alt2
server:
  port: 8443
  ssl:
    bundle: "web"
    server-name-bundles:
      - server-name: "alt1.example.com"
        bundle: "web-alt1"
      - server-name: "alt2.example.com"
        bundle: "web-alt2"

The bundle specified with server.ssl.bundle will be used for the default host, and for any client that does support SNI. This default bundle must be configured if any server.ssl.server-name-bundles are configured.spring-doc.cn

The server.ssl.bundle property can not be combined with the discrete Java KeyStore or PEM property options under server.ssl.

Configure HTTP/2

You can enable HTTP/2 support in your Spring Boot application with the server.http2.enabled configuration property. Both h2 (HTTP/2 over TLS) and h2c (HTTP/2 over TCP) are supported. To use h2, SSL must also be enabled. When SSL is not enabled, h2c will be used. You may, for example, want to use h2c when your application is running behind a proxy server that is performing TLS termination.spring-doc.cn

HTTP/2 With Tomcat

Spring Boot ships by default with Tomcat 10.1.x which supports h2c and h2 out of the box. Alternatively, you can use libtcnative for h2 support if the library and its dependencies are installed on the host operating system.spring-doc.cn

The library directory must be made available, if not already, to the JVM library path. You can do so with a JVM argument such as -Djava.library.path=/usr/local/opt/tomcat-native/lib. More on this in the official Tomcat documentation.spring-doc.cn

HTTP/2 With Jetty

For HTTP/2 support, Jetty requires the additional org.eclipse.jetty.http2:jetty-http2-server dependency. To use h2c no other dependencies are required. To use h2, you also need to choose one of the following dependencies, depending on your deployment:spring-doc.cn

HTTP/2 With Reactor Netty

The spring-boot-webflux-starter is using by default Reactor Netty as a server. Reactor Netty supports h2c and h2 out of the box. For optimal runtime performance, this server also supports h2 with native libraries. To enable that, your application needs to have an additional dependency.spring-doc.cn

Spring Boot manages the version for the io.netty:netty-tcnative-boringssl-static "uber jar", containing native libraries for all platforms. Developers can choose to import only the required dependencies using a classifier (see the Netty official documentation).spring-doc.cn

HTTP/2 With Undertow

Undertow supports h2c and h2 out of the box.spring-doc.cn

Configure the Web Server

Generally, you should first consider using one of the many available configuration keys and customize your web server by adding new entries in your application.properties or application.yaml file. See Discover Built-in Options for External Properties). The server.* namespace is quite useful here, and it includes namespaces like server.tomcat.*, server.jetty.* and others, for server-specific features. See the list of Common Application Properties.spring-doc.cn

The previous sections covered already many common use cases, such as compression, SSL or HTTP/2. However, if a configuration key does not exist for your use case, you should then look at WebServerFactoryCustomizer. You can declare such a component and get access to the server factory relevant to your choice: you should select the variant for the chosen Server (Tomcat, Jetty, Reactor Netty, Undertow) and the chosen web stack (servlet or reactive).spring-doc.cn

The example below is for Tomcat with the spring-boot-starter-web (servlet stack):spring-doc.cn

import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.stereotype.Component;

@Component
public class MyTomcatWebServerCustomizer implements WebServerFactoryCustomizer<TomcatServletWebServerFactory> {

	@Override
	public void customize(TomcatServletWebServerFactory factory) {
		// customize the factory here
	}

}
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory
import org.springframework.boot.web.server.WebServerFactoryCustomizer
import org.springframework.stereotype.Component

@Component
class MyTomcatWebServerCustomizer : WebServerFactoryCustomizer<TomcatServletWebServerFactory?> {

	override fun customize(factory: TomcatServletWebServerFactory?) {
		// customize the factory here
	}

}
Spring Boot uses that infrastructure internally to auto-configure the server. Auto-configured WebServerFactoryCustomizer beans have an order of 0 and will be processed before any user-defined customizers, unless it has an explicit order that states otherwise.

Once you have got access to a WebServerFactory using the customizer, you can use it to configure specific parts, like connectors, server resources, or the server itself - all using server-specific APIs.spring-doc.cn

In addition Spring Boot provides:spring-doc.cn

Server Servlet stack Reactive stack

Tomcatspring-doc.cn

TomcatServletWebServerFactoryspring-doc.cn

TomcatReactiveWebServerFactoryspring-doc.cn

Jettyspring-doc.cn

JettyServletWebServerFactoryspring-doc.cn

JettyReactiveWebServerFactoryspring-doc.cn

Undertowspring-doc.cn

UndertowServletWebServerFactoryspring-doc.cn

UndertowReactiveWebServerFactoryspring-doc.cn

Reactorspring-doc.cn

N/Aspring-doc.cn

NettyReactiveWebServerFactoryspring-doc.cn

As a last resort, you can also declare your own WebServerFactory bean, which will override the one provided by Spring Boot. When you do so, auto-configured customizers are still applied on your custom factory, so use that option carefully.spring-doc.cn

Spring Boot uses that infrastructure internally to auto-configure the server. Auto-configured WebServerFactoryCustomizer beans have an order of 0 and will be processed before any user-defined customizers, unless it has an explicit order that states otherwise.
Server Servlet stack Reactive stack

Tomcatspring-doc.cn

TomcatServletWebServerFactoryspring-doc.cn

TomcatReactiveWebServerFactoryspring-doc.cn

Jettyspring-doc.cn

JettyServletWebServerFactoryspring-doc.cn

JettyReactiveWebServerFactoryspring-doc.cn

Undertowspring-doc.cn

UndertowServletWebServerFactoryspring-doc.cn

UndertowReactiveWebServerFactoryspring-doc.cn

Reactorspring-doc.cn

N/Aspring-doc.cn

NettyReactiveWebServerFactoryspring-doc.cn

Add a Servlet, Filter, or Listener to an Application

In a servlet stack application, that is with the spring-boot-starter-web, there are two ways to add Servlet, Filter, ServletContextListener, and the other listeners supported by the Servlet API to your application:spring-doc.cn

Add a Servlet, Filter, or Listener by Using a Spring Bean

To add a Servlet, Filter, or servlet *Listener by using a Spring bean, you must provide a @Bean definition for it. Doing so can be very useful when you want to inject configuration or dependencies. However, you must be very careful that they do not cause eager initialization of too many other beans, because they have to be installed in the container very early in the application lifecycle. (For example, it is not a good idea to have them depend on your DataSource or JPA configuration.) You can work around such restrictions by initializing the beans lazily when first used instead of on initialization.spring-doc.cn

In the case of filters and servlets, you can also add mappings and init parameters by adding a FilterRegistrationBean or a ServletRegistrationBean instead of or in addition to the underlying component.spring-doc.cn

If no dispatcherType is specified on a filter registration, REQUEST is used. This aligns with the servlet specification’s default dispatcher type.spring-doc.cn

Like any other Spring bean, you can define the order of servlet filter beans; please make sure to check the Registering Servlets, Filters, and Listeners as Spring Beans section.spring-doc.cn

Disable Registration of a Servlet or Filter

As described earlier, any Servlet or Filter beans are registered with the servlet container automatically. To disable registration of a particular Filter or Servlet bean, create a registration bean for it and mark it as disabled, as shown in the following example:spring-doc.cn

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class MyFilterConfiguration {

	@Bean
	public FilterRegistrationBean<MyFilter> registration(MyFilter filter) {
		FilterRegistrationBean<MyFilter> registration = new FilterRegistrationBean<>(filter);
		registration.setEnabled(false);
		return registration;
	}

}
import org.springframework.boot.web.servlet.FilterRegistrationBean
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration

@Configuration(proxyBeanMethods = false)
class MyFilterConfiguration {

	@Bean
	fun registration(filter: MyFilter): FilterRegistrationBean<MyFilter> {
		val registration = FilterRegistrationBean(filter)
		registration.isEnabled = false
		return registration
	}

}

Add Servlets, Filters, and Listeners by Using Classpath Scanning

@WebServlet, @WebFilter, and @WebListener annotated classes can be automatically registered with an embedded servlet container by annotating a @Configuration class with @ServletComponentScan and specifying the package(s) containing the components that you want to register. By default, @ServletComponentScan scans from the package of the annotated class.spring-doc.cn

If no dispatcherType is specified on a filter registration, REQUEST is used. This aligns with the servlet specification’s default dispatcher type.spring-doc.cn

Configure Access Logging

Access logs can be configured for Tomcat, Undertow, and Jetty through their respective namespaces.spring-doc.cn

For instance, the following settings log access on Tomcat with a custom pattern.spring-doc.cn

server.tomcat.basedir=my-tomcat
server.tomcat.accesslog.enabled=true
server.tomcat.accesslog.pattern=%t %a %r %s (%D microseconds)
server:
  tomcat:
    basedir: "my-tomcat"
    accesslog:
      enabled: true
      pattern: "%t %a %r %s (%D microseconds)"
The default location for logs is a logs directory relative to the Tomcat base directory. By default, the logs directory is a temporary directory, so you may want to fix Tomcat’s base directory or use an absolute path for the logs. In the preceding example, the logs are available in my-tomcat/logs relative to the working directory of the application.

Access logging for Undertow can be configured in a similar fashion, as shown in the following example:spring-doc.cn

server.undertow.accesslog.enabled=true
server.undertow.accesslog.pattern=%t %a %r %s (%D milliseconds)
server.undertow.options.server.record-request-start-time=true
server:
  undertow:
    accesslog:
      enabled: true
      pattern: "%t %a %r %s (%D milliseconds)"
    options:
      server:
        record-request-start-time: true

Note that, in addition to enabling access logging and configuring its pattern, recording request start times has also been enabled. This is required when including the response time (%D) in the access log pattern. Logs are stored in a logs directory relative to the working directory of the application. You can customize this location by setting the server.undertow.accesslog.dir property.spring-doc.cn

Finally, access logging for Jetty can also be configured as follows:spring-doc.cn

server.jetty.accesslog.enabled=true
server.jetty.accesslog.filename=/var/log/jetty-access.log
server:
  jetty:
    accesslog:
      enabled: true
      filename: "/var/log/jetty-access.log"

By default, logs are redirected to System.err. For more details, see the Jetty documentation.spring-doc.cn

The default location for logs is a logs directory relative to the Tomcat base directory. By default, the logs directory is a temporary directory, so you may want to fix Tomcat’s base directory or use an absolute path for the logs. In the preceding example, the logs are available in my-tomcat/logs relative to the working directory of the application.

Running Behind a Front-end Proxy Server

If your application is running behind a proxy, a load-balancer or in the cloud, the request information (like the host, port, scheme…​) might change along the way. Your application may be running on 10.10.10.10:8080, but HTTP clients should only see example.org.spring-doc.cn

RFC7239 "Forwarded Headers" defines the Forwarded HTTP header; proxies can use this header to provide information about the original request. You can configure your application to read those headers and automatically use that information when creating links and sending them to clients in HTTP 302 responses, JSON documents or HTML pages. There are also non-standard headers, like X-Forwarded-Host, X-Forwarded-Port, X-Forwarded-Proto, X-Forwarded-Ssl, and X-Forwarded-Prefix.spring-doc.cn

If the proxy adds the commonly used X-Forwarded-For and X-Forwarded-Proto headers, setting server.forward-headers-strategy to NATIVE is enough to support those. With this option, the Web servers themselves natively support this feature; you can check their specific documentation to learn about specific behavior.spring-doc.cn

If this is not enough, Spring Framework provides a ForwardedHeaderFilter for the servlet stack and a ForwardedHeaderTransformer for the reactive stack. You can use them in your application by setting server.forward-headers-strategy to FRAMEWORK.spring-doc.cn

If you are using Tomcat and terminating SSL at the proxy, server.tomcat.redirect-context-root should be set to false. This allows the X-Forwarded-Proto header to be honored before any redirects are performed.
If your application runs in a supported Cloud Platform, the server.forward-headers-strategy property defaults to NATIVE. In all other instances, it defaults to NONE.

Customize Tomcat’s Proxy Configuration

If you use Tomcat, you can additionally configure the names of the headers used to carry “forwarded” information, as shown in the following example:spring-doc.cn

server.tomcat.remoteip.remote-ip-header=x-your-remote-ip-header
server.tomcat.remoteip.protocol-header=x-your-protocol-header
server:
  tomcat:
    remoteip:
      remote-ip-header: "x-your-remote-ip-header"
      protocol-header: "x-your-protocol-header"

Tomcat is also configured with a regular expression that matches internal proxies that are to be trusted. See the server.tomcat.remoteip.internal-proxies entry in the appendix for its default value. You can customize the valve’s configuration by adding an entry to application.properties, as shown in the following example:spring-doc.cn

server.tomcat.remoteip.internal-proxies=192\.168\.\d{1,3}\.\d{1,3}
server:
  tomcat:
    remoteip:
      internal-proxies: "192\\.168\\.\\d{1,3}\\.\\d{1,3}"
You can trust all proxies by setting the internal-proxies to empty (but do not do so in production).

You can take complete control of the configuration of Tomcat’s RemoteIpValve by switching the automatic one off (to do so, set server.forward-headers-strategy=NONE) and adding a new valve instance using a WebServerFactoryCustomizer bean.spring-doc.cn

If you are using Tomcat and terminating SSL at the proxy, server.tomcat.redirect-context-root should be set to false. This allows the X-Forwarded-Proto header to be honored before any redirects are performed.
If your application runs in a supported Cloud Platform, the server.forward-headers-strategy property defaults to NATIVE. In all other instances, it defaults to NONE.
You can trust all proxies by setting the internal-proxies to empty (but do not do so in production).

Enable Multiple Connectors with Tomcat

You can add an org.apache.catalina.connector.Connector to the TomcatServletWebServerFactory, which can allow multiple connectors, including HTTP and HTTPS connectors, as shown in the following example:spring-doc.cn

import org.apache.catalina.connector.Connector;

import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class MyTomcatConfiguration {

	@Bean
	public WebServerFactoryCustomizer<TomcatServletWebServerFactory> connectorCustomizer() {
		return (tomcat) -> tomcat.addAdditionalTomcatConnectors(createConnector());
	}

	private Connector createConnector() {
		Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
		connector.setPort(8081);
		return connector;
	}

}
import org.apache.catalina.connector.Connector
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory
import org.springframework.boot.web.server.WebServerFactoryCustomizer
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration

@Configuration(proxyBeanMethods = false)
class MyTomcatConfiguration {

	@Bean
	fun connectorCustomizer(): WebServerFactoryCustomizer<TomcatServletWebServerFactory> {
		return WebServerFactoryCustomizer { tomcat: TomcatServletWebServerFactory ->
			tomcat.addAdditionalTomcatConnectors(
				createConnector()
			)
		}
	}

	private fun createConnector(): Connector {
		val connector = Connector("org.apache.coyote.http11.Http11NioProtocol")
		connector.port = 8081
		return connector
	}

}

Enable Tomcat’s MBean Registry

Embedded Tomcat’s MBean registry is disabled by default. This minimizes Tomcat’s memory footprint. If you want to use Tomcat’s MBeans, for example so that they can be used by Micrometer to expose metrics, you must use the server.tomcat.mbeanregistry.enabled property to do so, as shown in the following example:spring-doc.cn

server.tomcat.mbeanregistry.enabled=true
server:
  tomcat:
    mbeanregistry:
      enabled: true

Enable Multiple Listeners with Undertow

Add an UndertowBuilderCustomizer to the UndertowServletWebServerFactory and add a listener to the Builder, as shown in the following example:spring-doc.cn

import io.undertow.Undertow.Builder;

import org.springframework.boot.web.embedded.undertow.UndertowServletWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class MyUndertowConfiguration {

	@Bean
	public WebServerFactoryCustomizer<UndertowServletWebServerFactory> undertowListenerCustomizer() {
		return (factory) -> factory.addBuilderCustomizers(this::addHttpListener);
	}

	private Builder addHttpListener(Builder builder) {
		return builder.addHttpListener(8080, "0.0.0.0");
	}

}
import io.undertow.Undertow
import org.springframework.boot.web.embedded.undertow.UndertowBuilderCustomizer
import org.springframework.boot.web.embedded.undertow.UndertowServletWebServerFactory
import org.springframework.boot.web.server.WebServerFactoryCustomizer
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration

@Configuration(proxyBeanMethods = false)
class MyUndertowConfiguration {

	@Bean
	fun undertowListenerCustomizer(): WebServerFactoryCustomizer<UndertowServletWebServerFactory> {
		return WebServerFactoryCustomizer { factory: UndertowServletWebServerFactory ->
			factory.addBuilderCustomizers(
				UndertowBuilderCustomizer { builder: Undertow.Builder -> addHttpListener(builder) })
		}
	}

	private fun addHttpListener(builder: Undertow.Builder): Undertow.Builder {
		return builder.addHttpListener(8080, "0.0.0.0")
	}

}

Create WebSocket Endpoints Using @ServerEndpoint

If you want to use @ServerEndpoint in a Spring Boot application that used an embedded container, you must declare a single ServerEndpointExporter @Bean, as shown in the following example:spring-doc.cn

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

@Configuration(proxyBeanMethods = false)
public class MyWebSocketConfiguration {

	@Bean
	public ServerEndpointExporter serverEndpointExporter() {
		return new ServerEndpointExporter();
	}

}
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.web.socket.server.standard.ServerEndpointExporter

@Configuration(proxyBeanMethods = false)
class MyWebSocketConfiguration {

	@Bean
	fun serverEndpointExporter(): ServerEndpointExporter {
		return ServerEndpointExporter()
	}

}

The bean shown in the preceding example registers any @ServerEndpoint annotated beans with the underlying WebSocket container. When deployed to a standalone servlet container, this role is performed by a servlet container initializer, and the ServerEndpointExporter bean is not required.spring-doc.cn