springboot自动装配原理

Z时代
2024-01-10
分类：综合

springboot自动装配原理

SpringBootApplication注解

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = { @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
        @Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication

@EnableAutoConfiguration完成了自动装配

@EnableXxx 注解一般用于开启某一项功能，是为了简化代码的导入，即使用了该类注

解，就会自动导入某些类。所以该类注解是组合注解，一般都会组合一个

@Import 注解，用

于导入指定的多个类，而被导入的类一般分为三种：配置类、选择器，与注册器。

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@AutoConfigurationPackage
@Import(AutoConfigurationImportSelector.class)
public @interface EnableAutoConfiguration

AutoConfigurationImportSelector类实现了查找XXAutoConfiguration类。核心方法

protected List<String> getCandidateConfigurations(AnnotationMetadata metadata, AnnotationAttributes attributes) {
　　　　// 查找jar包下面的META-INF/spring.factories
        List<String> configurations = SpringFactoriesLoader.loadFactoryNames(getSpringFactoriesLoaderFactoryClass(),
                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;
    }

spring.factories文件

# AutoConfigureCache auto-configuration imports org.springframework.boot.test.autoconfigure.core.AutoConfigureCache= org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration # AutoConfigureDataJdbc auto-configuration imports org.springframework.boot.test.autoconfigure.data.jdbc.AutoConfigureDataJdbc= org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration, org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration, org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration, org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration # AutoConfigureDataJpa auto-configuration imports org.springframework.boot.test.autoconfigure.orm.jpa.AutoConfigureDataJpa= org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration, org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration, org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration, org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration, org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration # AutoConfigureDataLdap auto-configuration imports org.springframework.boot.test.autoconfigure.data.ldap.AutoConfigureDataLdap= org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration, org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration, org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration # AutoConfigureDataMongo auto-configuration imports org.springframework.boot.test.autoconfigure.data.mongo.AutoConfigureDataMongo= 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.mongo.MongoAutoConfiguration, org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration, org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration # AutoConfigureDataNeo4j auto-configuration imports org.springframework.boot.test.autoconfigure.data.neo4j.AutoConfigureDataNeo4j= org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration, org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration, org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration # AutoConfigureDataRedis auto-configuration imports org.springframework.boot.test.autoconfigure.data.redis.AutoConfigureDataRedis= org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration, org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration # AutoConfigureJdbc auto-configuration imports org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureJdbc= org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration, org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration, org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration # AutoConfigureTestDatabase auto-configuration imports org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase= org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration # AutoConfigureJooq auto-configuration imports org.springframework.boot.test.autoconfigure.jooq.AutoConfigureJooq= org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration, org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration, org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration, org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration, org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration # AutoConfigureJson auto-configuration imports org.springframework.boot.test.autoconfigure.json.AutoConfigureJson= org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration, org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration, org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration # AutoConfigureJsonTesters auto-configuration imports org.springframework.boot.test.autoconfigure.json.AutoConfigureJsonTesters= org.springframework.boot.test.autoconfigure.json.JsonTestersAutoConfiguration, org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration, org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration, org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration # AutoConfigureWebClient auto-configuration imports org.springframework.boot.test.autoconfigure.web.reactive.AutoConfigureWebTestClient= org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration, org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration, org.springframework.boot.test.autoconfigure.web.reactive.WebTestClientAutoConfiguration # AutoConfigureWebFlux auto-configuration imports org.springframework.boot.test.autoconfigure.web.reactive.AutoConfigureWebFlux= org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration, org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration, org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration, org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration, org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration, org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration, org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration, org.springframework.boot.autoconfigure.web.reactive.error.ErrorWebFluxAutoConfiguration # AutoConfigureMockMvc auto-configuration imports org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc= org.springframework.boot.test.autoconfigure.web.servlet.MockMvcAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcSecurityAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebClientAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebDriverAutoConfiguration # AutoConfigureMockRestServiceServer org.springframework.boot.test.autoconfigure.web.client.AutoConfigureMockRestServiceServer= org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerAutoConfiguration # AutoConfigureRestDocs auto-configuration imports org.springframework.boot.test.autoconfigure.restdocs.AutoConfigureRestDocs= org.springframework.boot.test.autoconfigure.restdocs.RestDocsAutoConfiguration # AutoConfigureTestEntityManager auto-configuration imports org.springframework.boot.test.autoconfigure.orm.jpa.AutoConfigureTestEntityManager= org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManagerAutoConfiguration # AutoConfigureWebClient auto-configuration imports org.springframework.boot.test.autoconfigure.web.client.AutoConfigureWebClient= org.springframework.boot.test.autoconfigure.web.client.WebClientRestTemplateAutoConfiguration, org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration, org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration, org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration, org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration, org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration, org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration, org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration # AutoConfigureWebMvc auto-configuration imports org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureWebMvc= org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration, org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration, org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration, org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration, org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration, org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration, org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration, org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration, org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration, org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration, org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration, org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration, org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration, org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration, org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration # DefaultTestExecutionListenersPostProcessors org.springframework.boot.test.context.DefaultTestExecutionListenersPostProcessor= org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener$PostProcessor # Spring Test ContextCustomizerFactories org.springframework.test.context.ContextCustomizerFactory= org.springframework.boot.test.autoconfigure.OverrideAutoConfigurationContextCustomizerFactory, org.springframework.boot.test.autoconfigure.filter.TypeExcludeFiltersContextCustomizerFactory, org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizerFactory, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizerFactory # Test Execution Listeners org.springframework.test.context.TestExecutionListener= org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener

redis的自动装配过程

@Configuration
// 只有找到了RedisOperations这个类才会加载配置
@ConditionalOnClass(RedisOperations.class)
// 需要Redis的相关配置
@EnableConfigurationProperties(RedisProperties.class)
//导入jedis
@Import({ LettuceConnectionConfiguration.class, JedisConnectionConfiguration.class })
publicclass RedisAutoConfiguration {
    @Bean
　　//没有RedisTemplate的时候就会产生一个
    @ConditionalOnMissingBean(name = "redisTemplate")
public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory)
throws UnknownHostException {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);
return template;
    }
    @Bean
    @ConditionalOnMissingBean
public StringRedisTemplate stringRedisTemplate(RedisConnectionFactory redisConnectionFactory)
throws UnknownHostException {
        StringRedisTemplate template = new StringRedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
return template;
    }
}