那麼在引入角色介面LiuJianming之後，類與類之間的關係變為：

在這種情況下，WuJianDao還是和角色LiuJianming、演員LiuDeHua之間存在耦合關係。

• 其一 控制
• 其二 反轉

Public class WuJianDao {
  private LiuJianming ljm;
  //1：注入劉建明的具體扮演者
  public WuJianDao(LiuJianming ljm) {
     this.ljm = ljm;
  }
    public void tianTai() {
             ljm.declare(“我想做一個好人！”)
    }
}

Public class Director {
  public void direct() {
     //2.指定角色的扮演者
     LiuJianming ljm = new LiuDeHua();
     //3.注入具體扮演者到劇本中
     WuJianDao wjd = new WuJianDao(ljm);
     wjd.tianTai();
   }
}
 

Public class WuJianDao {
  private LiuJianming ljm;
  //1.屬性注入方法
  public void setLjm(LiuJianmin ljm) {
     this.ljm = ljm;
  }
  public void tianTai() {
     ljm.declare(“我想做一個好人！”)
    }
}

Public class Director {
  public void direct() {
     LiuJianming ljm = new LiuDeHua();
     WuJianDao wjd = new WuJianDao();
     //2.呼叫屬性Setter方法注入
     wjd.setLjm(ljm);
     wjd.tianTai();
}

Public interface ActorArrangable {
  void injectLjm(LiuJianming ljm);
}

Public class WuJianDao
implements ActorArrangable {
  private LiuJianming ljm;
  //1.實現介面方法
  public void injectLjm(LiuJianming ljm)
    {this.ljm = ljm; }
  public void tianTai() {
     ljm.declare(“我想做一個好人！”)
    }
}

Public class Director {
  public void direct() {
     LiuJianming ljm = new LiuDeHua();
     WuJianDao wjd= new WuJianDao();
     wjd.injectLjm(ljm);
     wjd.tianTai();
   }
}

<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:p="http://www.springframework.org/schema/p"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
  <bean id="ljm" class="cn.lovepi.chapter02.ioc.LiuDeHua"/>
  <bean id="wjd" class="cn.lovepi.chapter02.ioc.WuJianDao"
        p:geli-ref="ljm"/>
</beans>