Dependency injection (IoC)

Dependency injection settings are completed by declaring @Inject and @By annotations on the class member attributes, and only class objects managed by the Bean container support dependencies. Injection, below is an example:

• Example:

  // 业务接口
  public interface IDemo {
      String sayHi();
  }
  
  // 业务接口实现类1
  @Bean
  public class DemoOne implements IDemo {
      public String sayHi() {
          return "Hello, YMP! I'm DemoOne.";
      }
  }
  
  // 业务接口实现类2
  @Bean
  public class DemoTwo implements IDemo {
      public String sayHi() {
          return "Hello, YMP! I'm DemoTwo.";
      }
  }

• Test code:

  @Bean
  public class TestDemo {
  
      @Inject
      private IDemo __demo1;
  
      @Inject
      @By(DemoOne.class)
      private IDemo __demo2;
  
      public void sayHi() {
          // _demo1注入的将是最后被注册到容器的IDemo接口实现类
          System.out.println(__demo1.sayHi());
          // _demo2注入的是由@By注解指定的DemoOne类
          System.out.println(__demo2.sayHi());
      }
  
      public static void main(String[] args) throws Exception {
          YMP.get().init();
          try {
              TestDemo _demo = YMP.get().getBean(TestDemo.class);
              _demo.sayHi();
          } finally {
              YMP.get().destroy();
          }
      }
  }