通达信期权接口_Spring之ImportSelector接口浅析

新增ApplicationContextUtil类打印出容器中的bean

@Component
@Import(DogImportSelector.class)
public class ApplicationContextUtil implements ApplicationContextAware {
    private ApplicationContext applicationContext;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
        String[] names = applicationContext.getBeanDefinitionNames() ;
        for (String name:names
             ) {
            System.out.println(name);
        }
    }
}

启动项目打印结果如下：

selectImports方法返回String[],需要加入IOC容器进行管理的类都可以添加到数组之中，参数是AnnotationMetadata类型的，实现了ClassMetadata,AnnotatedTypeMetadata类，所以可以对@Import注解引入ImportSelector实现类所在的类上的注解及类实例本身进行操作，可以在selectImports方法中进行各种逻辑上的处理；

新增一个通达信期权接口,接口Dog

看下ImportSelector通达信期权接口,接口的源码

package org.springframework.context.annotation;

import org.springframework.core.type.AnnotationMetadata;

public interface ImportSelector {

	/**
	 * Select and return the names of which class(es) should be imported based on
	 * the {@link AnnotationMetadata} of the importing @{@link Configuration} class.
	 */
	String[] selectImports(AnnotationMetadata importingClassMetadata);

}

新增实现类BlackDog

public class BlackDog implements Dog {
    @Override
    public String dogName() {
        return '黑色Dog';
    }
}

Spring之ImportSelector接口浅析

新增实现类YellowDog

public class YellowDog implements Dog {
    @Override
    public String dogName() {
        return '黄色Dog';
    }
}

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