객체가 스스로 참조하는 객체를 생성하지 않고, 외부 환경(컨테이너)에서 삽입 되는 형태를 DI(Dependency Injection)라고 한다. 그리고, DI를 구현하는 방법은 2가지가 있다.

1. 생성자(Constructor) 방식

public class Shop {   
  private final StockManager stockManager;   
  private final String shopZipCode;   
  public Shop(StockManager stockManager, String shopZipCode) {   
       this.stockManager = stockManager;   
       this.shopZipCode = shopZipCode;   
  }   
}

2. 세터(Setter) 방식

public class Shop {   
  StockManager stockManager;   
  String shopZipCode;   
  /**  
  * @service name="StockManager"       
  */  
  public void setStockManager(StockManager stockManager) {   
      this.stockManager = stockManager;   
  }   
  /**  
  * @config name="shopZipCode"       
  */  
  public void setStockManager(String shopZipCode) {   
      this.shopZipCode= shopZipCode;   
  }   
  // TODO - Joe - how does setter injector do config ? Same way?   
  public void initialize() {   
      // all setXXXs are now done  
  }   
}