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解決springboot application.properties server.port配置問(wèn)題

更新時(shí)間：2021年08月13日 10:19:03 作者：quentinschuman

這篇文章主要介紹了解決springboot application.properties server.port配置問(wèn)題，具有很好的參考價(jià)值，希望對(duì)大家有所幫助。如有錯(cuò)誤或未考慮完全的地方，望不吝賜教

springboot application.properties server.port配置的問(wèn)題

近年來(lái)，springboot以其快速構(gòu)建方便便捷，開(kāi)箱即用，約定優(yōu)于配置（Convention Over Configuration）的特性深受廣大開(kāi)發(fā)者喜愛(ài)。

springboot已經(jīng)集成配置好了一套web開(kāi)發(fā)的默認(rèn)配置，開(kāi)發(fā)者可以無(wú)需修改任何配置即可開(kāi)始一個(gè)web工程，但是實(shí)際情況中有時(shí)候開(kāi)發(fā)者還是需要修改部分默認(rèn)配置項(xiàng)來(lái)使其更加契合自己的項(xiàng)目需求。

下面就其中一個(gè)小問(wèn)題做個(gè)記錄

在配置服務(wù)啟動(dòng)的端口時(shí)，springboot默認(rèn)在application.properties配置文件中提供了server.port配置項(xiàng)來(lái)

讓開(kāi)發(fā)者自行配置服務(wù)啟動(dòng)端口號(hào)，**但是注意：**

#服務(wù)啟動(dòng)端口號(hào)
server.port=8889

該配置項(xiàng)要想生效其實(shí)是依賴于項(xiàng)目中內(nèi)嵌的tomcat容器，如下圖：

內(nèi)嵌tomcat的jar包依賴包含在pom中

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

如果pom中不引人上述依賴，那么項(xiàng)目中不會(huì)導(dǎo)入內(nèi)嵌tomcat的jar包，相應(yīng)的application.properties配置文件中server.port配置項(xiàng)也將無(wú)法生效，因?yàn)樵撆渲庙?xiàng)實(shí)際上修改的就是內(nèi)嵌tomcat的web端口號(hào)。

Spring Boot server.port配置原理

我們經(jīng)常配置server.port=xxx，但其實(shí)這是一個(gè)比較復(fù)雜的過(guò)程才生效的，這次講講生效的過(guò)程。

1. autoConfigure

本質(zhì)來(lái)源于自動(dòng)配置

org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration

TomcatServletWebServerFactory

為什么是這個(gè)類，核心是beanPostProcess原理

@ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
public class ServerProperties {
 
	/**
	 * Server HTTP port.
	 */
	private Integer port;

beanPostProcess

public class WebServerFactoryCustomizerBeanPostProcessor implements BeanPostProcessor, BeanFactoryAware {
 
	private ListableBeanFactory beanFactory; 
	private List<WebServerFactoryCustomizer<?>> customizers;  
	@Override
	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
		if (bean instanceof WebServerFactory) {
			postProcessBeforeInitialization((WebServerFactory) bean);
		}
		return bean;
	} 
	
	@SuppressWarnings("unchecked")
	private void postProcessBeforeInitialization(WebServerFactory webServerFactory) {
		LambdaSafe.callbacks(WebServerFactoryCustomizer.class, getCustomizers(), webServerFactory)
				.withLogger(WebServerFactoryCustomizerBeanPostProcessor.class)
				.invoke((customizer) -> customizer.customize(webServerFactory));
	}
 
    private Collection<WebServerFactoryCustomizer<?>> getCustomizers() {
		if (this.customizers == null) {
			// Look up does not include the parent context
			this.customizers = new ArrayList<>(getWebServerFactoryCustomizerBeans());
			this.customizers.sort(AnnotationAwareOrderComparator.INSTANCE);
			this.customizers = Collections.unmodifiableList(this.customizers);
		}
		return this.customizers;
	}
 
	@SuppressWarnings({ "unchecked", "rawtypes" })
	private Collection<WebServerFactoryCustomizer<?>> getWebServerFactoryCustomizerBeans() {
		return (Collection) this.beanFactory.getBeansOfType(WebServerFactoryCustomizer.class, false, false).values();
	}

最終

beanFactory.getBeansOfType(WebServerFactoryCustomizer.class, false, false).values()

WebServerFactoryCustomizer對(duì)象.customize(webServerFactory)

@Configuration
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@ConditionalOnClass(ServletRequest.class)
@ConditionalOnWebApplication(type = Type.SERVLET)
@EnableConfigurationProperties(ServerProperties.class)
@Import({ ServletWebServerFactoryAutoConfiguration.BeanPostProcessorsRegistrar.class,
		ServletWebServerFactoryConfiguration.EmbeddedTomcat.class,
		ServletWebServerFactoryConfiguration.EmbeddedJetty.class,
		ServletWebServerFactoryConfiguration.EmbeddedUndertow.class })
public class ServletWebServerFactoryAutoConfiguration {
 
	@Bean
	public ServletWebServerFactoryCustomizer servletWebServerFactoryCustomizer(ServerProperties serverProperties) {
		return new ServletWebServerFactoryCustomizer(serverProperties);
	}

這里就將port設(shè)置好了。