注册bean到IOC容器

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[toc]

1.使用BeanFactoryPostProcessor

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@Component
public class ConstomBeadFactoryPostProcessor implements BeanFactoryPostProcessor {

    private Logger log = LoggerFactory.getLogger(ConstomBeadFactoryPostProcessor.class);

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {

        GenericBeanDefinition genericBeanDefinition = (GenericBeanDefinition) beanFactory.getBeanDefinition("demonBean");

        /**
         * 属性注入方式，
         * 	 * @see #AUTOWIRE_NO   0，默认 @Autowired
         * 	 * @see #AUTOWIRE_BY_NAME  setter方法
         * 	 * @see #AUTOWIRE_BY_TYPE
         * 	 * @see #AUTOWIRE_CONSTRUCTOR  构造方法注入
         * 	 * @see #AUTOWIRE_AUTODETECT
         */
        int autowireMode = genericBeanDefinition.getAutowireMode();
        log.debug("{}, autowireMode={}", genericBeanDefinition.getBeanClassName(), autowireMode);


        /**
         * 修改 bean的 构造方式
         */
        GenericBeanDefinition personBeanDefinition = (GenericBeanDefinition) beanFactory.getBeanDefinition("person");
        ConstructorArgumentValues constructorArgumentValues = new ConstructorArgumentValues();
        constructorArgumentValues.addIndexedArgumentValue(0,"zero");
        personBeanDefinition.setConstructorArgumentValues(constructorArgumentValues);

//        log.debug("beanFactory={}", beanFactory);

    }
}

2. 通过@Import

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@Import(ImportClassA.class) //导入普通类，ok
@Configuration
public class ConstomEnableAutoConfig {

}

3. 通过@Import + ImportBeanDefinitionRegistrar

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@Import(ConstomImportBeanDefinitionRegister.class) //导入注册器， ok    mybatis方式
@Configuration
public class ConstomEnableAutoConfig {

}

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public class ConstomImportBeanDefinitionRegister implements ImportBeanDefinitionRegistrar {
    @Override
    public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry beanDefinitionRegistry) {
        System.out.println("------------- ConstomImportBeanDefinitionRegister");

        /**
         * 注册一个 bean 到 IOC容器
         */
        RootBeanDefinition rootBeanDefinition = new RootBeanDefinition(InstA.class);
        beanDefinitionRegistry.registerBeanDefinition("instA", rootBeanDefinition);


        /**
         * 注册一个 bean 到 IOC容器
         */
        RootBeanDefinition beanDefinition = new RootBeanDefinition(IConstomMapper.class);
        beanDefinition.setBeanClass(ConstomMapperFactoryBean.class);
        beanDefinitionRegistry.registerBeanDefinition("iConstomMapper", rootBeanDefinition);

    }
}

4.通过@Import + ImportSelector

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@Import(ConstomImportSelector.class) // 批量导入，ok   springboot自动装配原理
@Configuration
public class ConstomEnableAutoConfig {

}
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public class ConstomImportSelector implements ImportSelector {
    // V1
//    @Override
//    public String[] selectImports(AnnotationMetadata annotationMetadata) {
//        return new String[]{"com.zero.beandefition.importtest.InstB"};
//    }

    /**
     * V2
     */
    @Override
    public String[] selectImports(AnnotationMetadata annotationMetadata) {
        // 读取 META-INF/spring.factories 文件配置
        // keys是 com.zero.beandefition.importtest.ImportConfig

        List<String> ts = SpringFactoriesLoader.loadFactoryNames(ConstomEnableAutoConfig.class,
            ConstomImportSelector.class.getClassLoader());

        ts = Lists.newArrayList("com.zero.beandefition.importtest.InstB");

//        return ts.toArray(new String[ts.size()]);
        return StringUtils.toStringArray(ts);
    }
}