250.Spring 依赖注入-构造器注入

/*带参数，方便利用构造器进行注入*/ 
 public CatDaoImpl(String message){ 
 this. message = message; 
 } 
<bean id="CatDaoImpl" class="com.CatDaoImpl"> 
<constructor-arg value=" message "></constructor-arg> 
</bean>
 public class Id { 
 private int id; 
 public int getId() { return id; } 
 public void setId(int id) { this.id = id; } 
} 
<bean id="id" class="com.id "> <property name="id" value="123"></property> </bean>