自动装配

AutoConfigurationImportSelector实现，返回实现类Class名称的数组，并将其装配到ioc容器

@AutoConfigurationPackage使用该注解的类所在的包及其子包下所有组件扫描到spring Ioc 容器中

public class User{    private Long id;    private String name;省略getter、setter、构造函数}

实现例子

public interface ImportSelector {    String[] selectImports(AnnotationMetadata var1);}      数组中可以指定需要装配到IOC容器的类      可以批量装配      通过逻辑处理来实现Bean的选择性装配(根据上下文决定那些类能够被IOC容器初始化)

扩展@Conditional条件装配

条件接口返回true注入，false不注入

font color=\"#e65100\

public class DogConditional implements Condition {    @Overridefont color=\"#f57f17\

全局bean注入

@ConditionalOnProperty@Configuration@ConditionalOnProperty(value=\"gp.bean0enable\

自动装配

public class UserConditional implements Condition {    @Overridefont color=\"#f57f17\

自动装配流程1.通过@Import(AutoConfigurationImportSelector)实现配置类导入，但是这里不是传统span style=\

@EnableAutoConfiguration

包含

user的条件装配-配置

dog的条件装配-配置

其中en.conf为全局配置用于区分注册什么类型的bean

@Configurationpublic class DemoConfig {    @Conditional(UserConditional.class)    @Bean(name = \"user\")    public User user(){        User user = new User();        user.setId(1L);        user.setName(\"男用户\");        return user;    }    @Conditional(DogConditional.class)    @Bean(name = \"dog\")    public Dog dog(){        Dog dog = new Dog();        dog.setId(2L);        dog.setName(\"小白\");        return dog;    }}

public class Dog {    private Long id;    private String name;省略getter、setter、构造函数}

@Import(AutoConfigurationImportSelector.class)导入的不是一个Configuration类是一个AutoConfigurationImportSelector类

测试例子

注入的UserBean

@SpringBootApplicationpublic class ConditionalApplication10000 {    public static void main(String[] args) {        System.setProperty(\"en.conf\

当Spring Ioc容器中存在GpBean时，才会加载ConditionConfig 

在application.properties或application.yml中，当gp.bean.enable=true时才会加载ConditionConfig这个bean，如果没匹配上也会加载因为matchIfMissing=true，默认false

@FunctionalInterfacepublic interface Condition {font color=\"#e65100\

实现方法

@ConditionalOnResource@Configuration@ConditionalOnResource(resource=\"gp.properties\")public class ConditionConfig{}

@SpringBootApplication

注解类

启动类

注入的DogBean

@Overridepublic String[] selectImports(AnnotationMetadata annotationMetadata) {     if (!isEnabled(annotationMetadata)) {          return NO_IMPORTS;     }    AutoConfigurationMetadata autoConfigurationMetadata =          AutoConfigurationMetadataLoader.loadMetadata(this.beanClassLoader);font color=\"#e65100\

@Configuration@ConditionalOnBean(GpBean.class)public class ConditionConfig{}

======= 注册 bean =======public class FirstClass {    private String name = \"FirstClass\";    构造、setter、getter、tostring省略}public class SecondClass {    private String name = \"SecondClass\";    构造、setter、getter、tostring省略}=======ImportSelector实现类==public class GpImportSelector implements ImportSelector {    @Override    public String[] selectImports(AnnotationMetadata annotationMetadata) {font color=\"#f57f17\