@Configuration与@Component作为配置类的区别详解

/**
 * @Description 测试用的配置类
 * @Author 弟中弟
 * @CreateTime 2019/6/18 14:35
 */
@Configuration
public class MyBeanConfig {
 @Bean
 public Country country(){
  return new Country();
 }
 @Bean
 public UserInfo userInfo(){
  return new UserInfo(country());
 }
}

/**
 * @Description 测试用的配置类
 * @Author 弟中弟
 * @CreateTime 2019/6/18 14:36
 */
@Component
public class MyBeanConfig {
 @Bean
 public Country country(){
  return new Country();
 }
 @Bean
 public UserInfo userInfo(){
  return new UserInfo(country());
 }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoTest {

  @Autowired
  private Country country;

  @Autowired
  private UserInfo userInfo;

  @Test
  public void myTest() {
    boolean result = userInfo.getCountry() == country;
    System.out.println(result ? "同一个country" : "不同的country");
  }

}

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface Configuration {
  @AliasFor(
    annotation = Component.class
  )
  String value() default "";
}

<bean id="country" class="com.hhh.demo.Country" scope="singleton"/>

/**
 * @Description 测试用的配置类
 * @Author 弟中弟
 * @CreateTime 2019/6/18 14:36
 */
@Component
public class MyBeanConfig {
 @Autowired
 private Country country;
 @Bean
 public Country country(){
  return new Country();
 }
 @Bean
 public UserInfo userInfo(){
  return new UserInfo(country);
 }
}