Advanced wire

spring-waring

@Autowired
public void setDessert(Dessert dessert) {
  this.dessert = dessert;
}


===
Dessert.java接口有多个实现类
@Component
public class Cake implements Dessert { ... }
@Component
public class Cookies implements Dessert { ... }
@Component
public class IceCream implements Dessert { ... }

这时Spring会弄混解决办法
@Primary注释，可以和@Component和@Bean公用

auto-wire用法
---
@Component
@Primary
public class IceCream implements Dessert { ... }

JavaConf用法
---
@Bean
@Primary
public Dessert iceCream() {
    return new IceCream();
}

XML用法
<bean id="iceCream"
  class="com.desserteater.IceCream"
  primary="true" />