对象放到spring容器

把一个对象放到spring容器中
1.FactoryBean

@Component
public class MyFactoryBean implements FactoryBean {
    
    @Override
    public Object getObject() throws Exception {
        return null;//返回一个bean
    }

    @Override
    public Class<?> getObjectType() {
        return null;//类的类型
    }

    @Override
    public boolean isSingleton() {
        return false;
    }
}

2.registerSingle
AnnotationConfigApplicationContext.getBeanFactory().registerSingleton( "xx",new XXXX() );
3.@Bean

    @Bean
    public IndexDao indexDao(){
        return new IndexDao();
    }