技术标签: spring 详细 spring boot java 专业
大家在使用springboot的时候不得不感叹它的功能强大和方便,但是作为一个合格的程序员,单纯只是去使用框架是远远不够的!
我们知道,Spring Boot 项目创建完成后,即使不进行任何的配置,也能够顺利地运行,这都要归功于 Spring Boot 的自动化配置。
Spring Boot 默认使用 application.properties 或 application.yml 作为其全局配置文件,我们可以在该配置文件中对各种自动配置属性(server.port、logging.level.* 、spring.config.active.no-profile 等等)进行修改,并使之生效,那么您有没有想过这些属性是否有据可依呢?
而这个答案的回答是"是,肯定有据可依",当我们感叹框架功能之强大、使用之便捷之余,我们也要有深究原理的精神,任何框架的功能的强大和方便都是由一行行的代码所支撑的。
springboot的自动装箱功能的实现是基于spring factories机制所实现的。Spring Factories 机制是 Spring Boot 中的一种服务发现机制,这种扩展机制与 Java SPI 机制十分相似(而java的SPI机制这篇博客,我之前想着发表的,但是因为一些原因导致没有发表成功,在之后这段时间,我会找个时间发布,如果有不懂SPI服务的到时候可以去看一看)。Spring Boot 会自动扫描所有 Jar 包类路径下 META-INF/spring.factories 文件,并读取其中的内容,进行实例化,这种机制也是 Spring Boot Starter 的基础。
而spring factories机制的实现主要依赖一个SpringFactoriesLoader类和多个spring.factories 文件。
spring.factories文件和java属性文件(.properties)差不多,其中包含一组或多组键值对(key=vlaue),其中,key 的取值为接口的完全限定名;value 的取值为接口实现类的完全限定名,一个接口可以设置多个实现类,不同实现类之间使用“,”隔开,例如:
org.springframework.boot.autoconfigure.AutoConfigurationImportFilter=\
org.springframework.boot.autoconfigure.condition.OnBeanCondition,\
org.springframework.boot.autoconfigure.condition.OnClassCondition,\
org.springframework.boot.autoconfigure.condition.OnWebApplicationCondition
spring-core 包里定义了 SpringFactoriesLoader 类,这个类会扫描所有 Jar 包类路径下的 META-INF/spring.factories 文件,并获取指定接口的配置。在 SpringFactoriesLoader 类中定义了两个对外的方法,如下表。
方法 | 描述 |
---|---|
loadFactories(Class factoryType, @Nullable ClassLoader classLoader) | 根据接口获取其实现类的实例;该方法返回的是实现类对象列表 |
loadFactoryNames(Class<?> factoryType, @Nullable ClassLoader classLoader) | 根据接口l获取其实现类的名称;该方法返回的是实现类的类名的列表 |
以上两个方法的关键都是从指定的 ClassLoader 中获取 spring.factories 文件,并解析得到类名列表,具体代码如下:
loadFactories方法:能够获取指定接口的实现类对象
public static <T> List<T> loadFactories(Class<T> factoryType, @Nullable ClassLoader classLoader) {
Assert.notNull(factoryType, "'factoryType' must not be null");
ClassLoader classLoaderToUse = classLoader;
if (classLoader == null) {
classLoaderToUse = SpringFactoriesLoader.class.getClassLoader();
}
List<String> factoryImplementationNames = loadFactoryNames(factoryType, classLoaderToUse);
if (logger.isTraceEnabled()) {
logger.trace("Loaded [" + factoryType.getName() + "] names: " + factoryImplementationNames);
}
List<T> result = new ArrayList(factoryImplementationNames.size());
Iterator var5 = factoryImplementationNames.iterator();
while(var5.hasNext()) {
String factoryImplementationName = (String)var5.next();
result.add(instantiateFactory(factoryImplementationName, factoryType, classLoaderToUse));
}
AnnotationAwareOrderComparator.sort(result);
return result;
}
loadFactoryNames方法:能够根据接口获取其实现类类名的集合
public static List<String> loadFactoryNames(Class<?> factoryType, @Nullable ClassLoader classLoader) {
ClassLoader classLoaderToUse = classLoader;
if (classLoader == null) {
classLoaderToUse = SpringFactoriesLoader.class.getClassLoader();
}
String factoryTypeName = factoryType.getName();
return (List)loadSpringFactories(classLoaderToUse).getOrDefault(factoryTypeName, Collections.emptyList());
}
而在上面的loadFactoryNames方法中调用了一个内部方法loadSpringFactories方法,这个方法的作用能够读取该项目中所有 Jar 包类路径下 META-INF/spring.factories 文件的配置内容,并以 Map 集合的形式返回。
private static Map<String, List<String>> loadSpringFactories(ClassLoader classLoader) {
Map<String, List<String>> result = (Map)cache.get(classLoader);
if (result != null) {
return result;
} else {
HashMap result = new HashMap();
try {
Enumeration urls = classLoader.getResources("META-INF/spring.factories");
while(urls.hasMoreElements()) {
URL url = (URL)urls.nextElement();
UrlResource resource = new UrlResource(url);
Properties properties = PropertiesLoaderUtils.loadProperties(resource);
Iterator var6 = properties.entrySet().iterator();
while(var6.hasNext()) {
Entry<?, ?> entry = (Entry)var6.next();
String factoryTypeName = ((String)entry.getKey()).trim();
String[] factoryImplementationNames = StringUtils.commaDelimitedListToStringArray((String)entry.getValue());
String[] var10 = factoryImplementationNames;
int var11 = factoryImplementationNames.length;
for(int var12 = 0; var12 < var11; ++var12) {
String factoryImplementationName = var10[var12];
((List)result.computeIfAbsent(factoryTypeName, (key) -> {
return new ArrayList();
})).add(factoryImplementationName.trim());
}
}
}
result.replaceAll((factoryType, implementations) -> {
return (List)implementations.stream().distinct().collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
});
cache.put(classLoader, result);
return result;
} catch (IOException var14) {
throw new IllegalArgumentException("Unable to load factories from location [META-INF/spring.factories]", var14);
}
}
}
到此,我们就已经了解了spring factories的基本原理。下面我们再来了解自动配置的加载是如何实现的
Spring Boot 自动化配置也是基于 Spring Factories 机制实现的,在 spring-boot-autoconfigure-xxx.jar 类路径下的 META-INF/spring.factories 中设置了 Spring Boot 自动配置的内容 ,如下。
# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\
org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\
org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\
org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\
org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\
org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\
org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration,\
org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\
org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\
org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRestClientAutoConfiguration,\
org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.r2dbc.R2dbcDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.r2dbc.R2dbcRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\
org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientAutoConfiguration,\
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\
org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\
org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\
org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\
org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\
org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration,\
org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration,\
org.springframework.boot.autoconfigure.influx.InfluxDbAutoConfiguration,\
org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\
org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\
org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\
org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\
org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration,\
org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\
org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\
org.springframework.boot.autoconfigure.neo4j.Neo4jAutoConfiguration,\
org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\
org.springframework.boot.autoconfigure.quartz.QuartzAutoConfiguration,\
org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration,\
org.springframework.boot.autoconfigure.r2dbc.R2dbcTransactionManagerAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketMessagingAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketRequesterAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketServerAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketStrategiesAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration,\
org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration,\
org.springframework.boot.autoconfigure.security.rsocket.RSocketSecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.saml2.Saml2RelyingPartyAutoConfiguration,\
org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\
org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.client.reactive.ReactiveOAuth2ClientAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.resource.servlet.OAuth2ResourceServerAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.resource.reactive.ReactiveOAuth2ResourceServerAutoConfiguration,\
org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\
org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration,\
org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration,\
org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\
org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\
org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.HttpHandlerAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.error.ErrorWebFluxAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.reactive.WebSocketReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.servlet.WebSocketMessagingAutoConfiguration,\
org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration,\
org.springframework.boot.autoconfigure.webservices.client.WebServiceTemplateAutoConfiguration
以上配置中,value 取值是由多个 xxxAutoConfiguration (使用逗号分隔)组成,每个 xxxAutoConfiguration 都是一个自动配置类。Spring Boot 启动时,会利用 Spring-Factories 机制,将这些 xxxAutoConfiguration 实例化并作为组件加入到容器中,以实现 Spring Boot 的自动配置。
@EnableAutoConfiguration 注解用于开启 Spring Boot 的自动配置功能, 它使用 Spring 框架提供的 @Import 注解通过 AutoConfigurationImportSelector类(选择器)给容器中导入自动配置组件。而这个注解是SpringBootApplication的元注解之一。
而这个能够帮助SpringBootApplication这个注解实现自动装配的功能,当然,SpringBootApplication这个注解不单纯只有这一个功能,本文不对其他功能进行一个解释,再提一嘴SpringBootApplication注解的功能主要都是由它的元注解所完成。
好了,回到正题,我们知道SpringBootApplication的自动配置功能是由EnableAutoConfiguration 注解所实现的,我们现在就去看看这个注解
在这个注解中我们需要关注其中的Import元注解,它导入了一个AutoConfigurationImportSelector配置类,这个配置类会帮我们的EnableAutoConfiguration 注解完成自动配置功能。
AutoConfigurationImportSelector 类实现了 DeferredImportSelector 接口,AutoConfigurationImportSelector 中还包含一个静态内部类 AutoConfigurationGroup,它实现了 DeferredImportSelector 接口的内部接口 Group(Spring 5 新增)
在这个类中,我们需要重点关注三个方法:
他们的执行顺序是:getImportGroup—>process—>selectImports
下面我们将分别对以上 3 个方法及其调用过程进行介绍。
AutoConfigurationImportSelector 类中 getImportGroup() 方法主要用于获取实现了 DeferredImportSelector.Group 接口的类,代码如下
public Class<? extends Group> getImportGroup() {
return AutoConfigurationImportSelector.AutoConfigurationGroup.class;
}
静态内部类 AutoConfigurationGroup 中的核心方法是 process(),该方法通过调用 getAutoConfigurationEntry() 方法读取 spring.factories 文件中的内容,获得自动配置类的集合,代码如下
public void process(AnnotationMetadata annotationMetadata, DeferredImportSelector deferredImportSelector) {
Assert.state(deferredImportSelector instanceof AutoConfigurationImportSelector, () -> {
return String.format("Only %s implementations are supported, got %s", AutoConfigurationImportSelector.class.getSimpleName(), deferredImportSelector.getClass().getName());
});
AutoConfigurationImportSelector.AutoConfigurationEntry autoConfigurationEntry = ((AutoConfigurationImportSelector)deferredImportSelector).getAutoConfigurationEntry(annotationMetadata);
this.autoConfigurationEntries.add(autoConfigurationEntry);
Iterator var4 = autoConfigurationEntry.getConfigurations().iterator();
while(var4.hasNext()) {
String importClassName = (String)var4.next();
this.entries.putIfAbsent(importClassName, annotationMetadata);
}
}
getAutoConfigurationEntry() 方法通过调用 getCandidateConfigurations() 方法来获取自动配置类的完全限定名,并在经过排除、过滤等处理后,将其缓存到成员变量中,具体代码如下。
protected AutoConfigurationImportSelector.AutoConfigurationEntry getAutoConfigurationEntry(AnnotationMetadata annotationMetadata) {
if (!this.isEnabled(annotationMetadata)) {
return EMPTY_ENTRY;
} else {
AnnotationAttributes attributes = this.getAttributes(annotationMetadata);
List<String> configurations = this.getCandidateConfigurations(annotationMetadata, attributes);
configurations = this.removeDuplicates(configurations);
Set<String> exclusions = this.getExclusions(annotationMetadata, attributes);
this.checkExcludedClasses(configurations, exclusions);
configurations.removeAll(exclusions);
configurations = this.getConfigurationClassFilter().filter(configurations);
this.fireAutoConfigurationImportEvents(configurations, exclusions);
return new AutoConfigurationImportSelector.AutoConfigurationEntry(configurations, exclusions);
}
}
在 getCandidateConfigurations() 方法中,根据 Spring Factories 机制调用 SpringFactoriesLoader 的 loadFactoryNames() 方法,根据 EnableAutoConfiguration.class (自动配置接口)获取其实现类(自动配置类)的类名的集合
protected List<String> getCandidateConfigurations(AnnotationMetadata metadata, AnnotationAttributes attributes) {
List<String> configurations = SpringFactoriesLoader.loadFactoryNames(this.getSpringFactoriesLoaderFactoryClass(), this.getBeanClassLoader());
Assert.notEmpty(configurations, "No auto configuration classes found in META-INF/spring.factories. If you are using a custom packaging, make sure that file is correct.");
return configurations;
}
protected Class<?> getSpringFactoriesLoaderFactoryClass() {
return EnableAutoConfiguration.class;
}
以上所有方法执行完成后,selectImports() 会将 process() 方法处理后得到的自动配置类,进行过滤、排除,最后将所有自动配置类添加到容器中
public Iterable<Entry> selectImports() {
if (this.autoConfigurationEntries.isEmpty()) {
return Collections.emptyList();
} else {
Set<String> allExclusions = (Set)this.autoConfigurationEntries.stream().map(AutoConfigurationImportSelector.AutoConfigurationEntry::getExclusions).flatMap(Collection::stream).collect(Collectors.toSet());
Set<String> processedConfigurations = (Set)this.autoConfigurationEntries.stream().map(AutoConfigurationImportSelector.AutoConfigurationEntry::getConfigurations).flatMap(Collection::stream).collect(Collectors.toCollection(LinkedHashSet::new));
processedConfigurations.removeAll(allExclusions);
return (Iterable)this.sortAutoConfigurations(processedConfigurations, this.getAutoConfigurationMetadata()).stream().map((importClassName) -> {
return new Entry((AnnotationMetadata)this.entries.get(importClassName), importClassName);
}).collect(Collectors.toList());
}
}
好了,到此,我们的springboot的自动装箱原理就已经讲解完毕,如果觉得有收获的话,就给博主点点赞吧(o( ̄︶ ̄)o)。
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文章浏览阅读894次。Q: SylixOS 版权是什么形式, 是否分为<开发版税>和<运行时版税>.A: SylixOS 是开源并免费的操作系统, 支持 BSD/GPL 协议(GPL 版本暂未确定). 没有任何的运行时版税. 您可以用她来做任何 您喜欢做的项目. 也可以修改 SylixOS 的源代码, 不需要支付任何费用. 当然笔者希望您可以将使用 SylixOS 开发的项目 (不需要开源)或对 SylixOS 源码的修改及时告知笔者.需要指出: SylixOS 本身仅是笔者用来提升自己水平而开发的_select函数 导致堆栈溢出 sylixos