SpringBoot常用配置简介

1. SpringBoot中几个常用的配置的简单介绍

• 一个简单的Spring.factories

  # Bootstrap components org.springframework.cloud.bootstrap.BootstrapConfiguration=\ org.springframework.cloud.config.server.bootstrap.ConfigServerBootstrapConfiguration # Application listeners org.springframework.context.ApplicationListener=\ org.springframework.cloud.config.server.bootstrap.ConfigServerBootstrapApplicationListener       # Autoconfiguration org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ org.springframework.cloud.config.server.config.EncryptionAutoConfiguration,\ org.springframework.cloud.config.server.config.SingleEncryptorAutoConfiguration

• BootstrapConfiguration简介

  Spring.factories中的配置项， org.springframework.cloud.bootstrap.BootstrapConfiguration，会在Spring启动之前的准备上下文阶段将其加入到容器中。我们在介绍 一文中曾详细解释Configuration中的解析。BootstrapConfiguration是在刷新（refresh）阶段将class作为预选的配置类@Configuration注入到容器中的，在阶段会解析此class。

• 加载BootstrapConfiguration配置的类

List
    
      names = SpringFactoriesLoader                .loadFactoryNames(BootstrapConfiguration.class, classLoader);        for (String name : StringUtils.commaDelimitedListToStringArray(                environment.getProperty("spring.cloud.bootstrap.sources", ""))) {            names.add(name);        }        // TODO: is it possible or sensible to share a ResourceLoader?        SpringApplicationBuilder builder = new SpringApplicationBuilder()                .profiles(environment.getActiveProfiles()).bannerMode(Mode.OFF)                .environment(bootstrapEnvironment)                .properties("spring.application.name:" + configName)                .registerShutdownHook(false).logStartupInfo(false).web(false);        List
     
      > sources = new ArrayList<>();        for (String name : names) {            Class
       cls = ClassUtils.resolveClassName(name, null);            try {                cls.getDeclaredAnnotations();            }            catch (Exception e) {                continue;            }            sources.add(cls);        }        builder.sources(sources.toArray(new Class[sources.size()]));        AnnotationAwareOrderComparator.sort(sources);        final ConfigurableApplicationContext context = builder.run();
     
    

• 加载BootstrapConfiguration配置的类

private void prepareContext(ConfigurableApplicationContext context,ConfigurableEnvironment environment, SpringApplicationRunListeners listeners,ApplicationArguments applicationArguments, Banner printedBanner) {        context.setEnvironment(environment);        postProcessApplicationContext(context);        applyInitializers(context);        listeners.contextPrepared(context);        if (this.logStartupInfo) {            logStartupInfo(context.getParent() == null);            logStartupProfileInfo(context);        }    // Add boot specific singleton beans        context.getBeanFactory().registerSingleton("springApplicationArguments",                applicationArguments);        if (printedBanner != null) {            context.getBeanFactory().registerSingleton("springBootBanner", printedBanner);        }        // Load the sources        Set

• ApplicationListener简介

  org.springframework.context.ApplicationListener会在SpringBoot中几个典型事件产生后调用onApplicationEvent方法。详见。

• Autoconfiguration简介

  org.springframework.boot.autoconfigure.EnableAutoConfiguration是SpringBoot中最常见配置，用于自动配置。只要有@EnableAutoConfiguration注解，该配置的所有类都会自动加载到Spring容器中。