Spring Boot 自动配置的实现

@suppresswarnings ( "deprecation" )

@target (elementtype.type)

@retention (retentionpolicy.runtime)

@documented

@inherited

@autoconfigurationpackage

@import (enableautoconfigurationimportselector. class )

public @interface enableautoconfiguration {

   string enabled_override_property = "spring.boot.enableautoconfiguration" ;

   /**

    * exclude specific auto-configuration classes such that they will never be applied.

    * @return the classes to exclude

    */

   class <?>[] exclude() default {};

   /**

    * exclude specific auto-configuration class names such that they will never be

    * applied.

    * @return the class names to exclude

    * @since 1.3.0

    */

   string[] excludename() default {};

}

public class enableautoconfigurationimportselector

     extends autoconfigurationimportselector {

   @override

   protected boolean isenabled(annotationmetadata metadata) {

     if (getclass().equals(enableautoconfigurationimportselector. class )) {

       return getenvironment().getproperty(

           enableautoconfiguration.enabled_override_property, boolean . class ,

           true );

     }

     return true ;

   }

}

}

@override

   public string[] selectimports(annotationmetadata annotationmetadata) {

     if (!isenabled(annotationmetadata)) {

       return no_imports;

     }

     try {

       //1、 自动配置的元数据 spring-autocomfigure-metadata.properties

       // 自动配置的开启条件

       autoconfigurationmetadata autoconfigurationmetadata = autoconfigurationmetadataloader

           .loadmetadata( this .beanclassloader);

       annotationattributes attributes = getattributes(annotationmetadata);

       // 获取设置的自动配置列表 spring.factories

       list<string> configurations = getcandidateconfigurations(annotationmetadata,

           attributes);

       configurations = removeduplicates(configurations);

       configurations = sort(configurations, autoconfigurationmetadata);

       // 获取要排除的自动配置列表，可以通过 注解@enableautoconfiguration 的exclude和

        // 配置文件设置 spring.autoconfigure.exclude key的值

       set<string> exclusions = getexclusions(annotationmetadata, attributes);

       checkexcludedclasses(configurations, exclusions);

       configurations.removeall(exclusions);

        // 通过 spring-autocomfigure-metadata.properties conditiononclass 条件进行过滤

       configurations = filter(configurations, autoconfigurationmetadata);

       fireautoconfigurationimportevents(configurations, exclusions);

       return configurations.toarray( new string[configurations.size()]);

     }

     catch (ioexception ex) {

       throw new illegalstateexception(ex);

     }

   }

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.cloud.cloudautoconfiguration,\

org.springframework.boot.autoconfigure.context.configurationpropertiesautoconfiguration,\

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.cassandrarepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.couchbasedataautoconfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.couchbaserepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.elasticsearchautoconfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.elasticsearchdataautoconfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.elasticsearchrepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.jpa.jparepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.ldap.ldapdataautoconfiguration,\

org.springframework.boot.autoconfigure.data.ldap.ldaprepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.mongo.mongodataautoconfiguration,\

org.springframework.boot.autoconfigure.data.mongo.mongorepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.neo4j.neo4jdataautoconfiguration,\

org.springframework.boot.autoconfigure.data.neo4j.neo4jrepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.solr.solrrepositoriesautoconfiguration,\

org.springframework.boot.autoconfigure.data.redis.redisautoconfiguration,\

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.jest.jestautoconfiguration,\

org.springframework.boot.autoconfigure.freemarker.freemarkerautoconfiguration,\

org.springframework.boot.autoconfigure.gson.gsonautoconfiguration,\

org.springframework.boot.autoconfigure.h2.h2consoleautoconfiguration,\

org.springframework.boot.autoconfigure.hateoas.hypermediaautoconfiguration,\

@configuration

@conditionalonbean (datasource. class )

@conditionalonclass (jparepository. class )

@conditionalonmissingbean ({ jparepositoryfactorybean. class ,

     jparepositoryconfigextension. class })

@conditionalonproperty (prefix = "spring.data.jpa.repositories" , name = "enabled" , havingvalue = "true" , matchifmissing = true )

@import (jparepositoriesautoconfigureregistrar. class )

@autoconfigureafter (hibernatejpaautoconfiguration. class )

public class jparepositoriesautoconfiguration {

}

@target ({ elementtype.type, elementtype.method })

@retention (retentionpolicy.runtime)

@documented

@conditional (onbeancondition. class )

public @interface conditionalonbean {

   /**

    * the class type of bean that should be checked. the condition matches when any of

    * the classes specified is contained in the {@link applicationcontext}.

    * @return the class types of beans to check

    */

   class <?>[] value() default {};

   /**

    * the class type names of bean that should be checked. the condition matches when any

    * of the classes specified is contained in the {@link applicationcontext}.

    * @return the class type names of beans to check

    */

   string[] type() default {};

   /**

    * the annotation type decorating a bean that should be checked. the condition matches

    * when any of the annotations specified is defined on a bean in the

    * {@link applicationcontext}.

    * @return the class-level annotation types to check

    */

   class <? extends annotation>[] annotation() default {};

   /**

    * the names of beans to check. the condition matches when any of the bean names

    * specified is contained in the {@link applicationcontext}.

    * @return the name of beans to check

    */

   string[] name() default {};

   /**

    * strategy to decide if the application context hierarchy (parent contexts) should be

    * considered.

    * @return the search strategy

    */

   searchstrategy search() default searchstrategy.all;

}