创建注解和对象
1.例子
/**
自定义注解 ,作用当spring扫描类上面有该注解时自动创建bean到spring容器中
**/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD, ElementType.ANNOTATION_TYPE})
public @interface MyAnnotion {
}
@MyAnnotion
public class HelloWord {
private String name = "lsr";
public String say(){
return "hello "+name;
}
}
2.定义DefinitionRegistryPostProcessor
@Configuration
public class DefinitionRegistryPostProcessor implements BeanDefinitionRegistryPostProcessor {
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory arg0) throws BeansException {
}
/**
* 先执行postProcessBeanDefinitionRegistry方法
* 在执行postProcessBeanFactory方法
*/
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
扫描自定义注解
ClassPathBeanDefinitionScanner scanner = new
ClassPathBeanDefinitionScanner(registry);
// bean 的名字生成规则在AnnotationBeanNameGenerator
scanner.setBeanNameGenerator(new AnnotationBeanNameGenerator());
// 设置哪些注解的扫描
scanner.addIncludeFilter(new AnnotationTypeFilter(MyAnnotion.class));
scanner.scan("com.anyly");
// 注意helloWord已经注册到容器中. 细看AnnotationBeanNameGenerator 的
generateBeanName()
}
}
3.测试bean是否在spring容器中
public static void main(String[] args) {
ApplicationContext applicationContext = SpringApplication.run(ApplicationBoot.class);
HelloWord helloWord = applicationContext.getBean("helloWord", HelloWord.class);
System.out.println(helloWord.say());
}
注意:默认扫描到的对象bean名字是开头大些转小写例如 HelloWord -> helloWord
