示例

@Component
public class IndexA {

    @Autowired
    IndexB bbb;

    public IndexA() {
        System.out.println("IndexA constructor...");
    }

    public void printf(){
        System.out.println("indexA printf : ");
        System.out.println("indexB --> " + (bbb == null ? null : bbb.getClass().getName()));
    }
}

@Component
public class IndexB {

    @Autowired
    IndexA aaa;

    public IndexB() {
        System.out.println("IndexB constructor...");
    }

    public void printf(){
        System.out.println("indexB printf : ");
        System.out.println("indexA --> " + (aaa == null ? null : aaa.getClass().getName()));
    }
}

@Configuration
@ComponentScan({
         "com.study.ioc.cyc"
})
public class StartConfig {
}