Bean的自动装配4

Bean的自动装配---Constructor

Constructor模式

与byType的方式类似，不同之处在于它应用于构造器参数。如果在容器中没有找到与构造器参数类型一致的bean，那么将会抛出异常。

 

案例：
AddressServiceImpl.java
public class AddressServiceImpl {
  private String address;

public void setAddress(String address) {
	this.address = address;
}  
}
HomeAdsressServiceImpl.java
public class HomeAdsressServiceImpl {
	private String address;

	public void setAddress(String address) {
		this.address = address;
	}
	public HomeAdsressServiceImpl() {
		super();
	}
	public HomeAdsressServiceImpl(String address) {
		super();
		this.address = address;
	}
}
EmpServiceImpl.java
public class EmpServiceImpl {
	private AddressServiceImpl companyAddress;

	public EmpServiceImpl(AddressServiceImpl companyAddress) {
		super();
		this.companyAddress = companyAddress;
	}
}
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
           
	<bean id="addressServiceImpl" class="cn.csdn.service.AddressServiceImpl"
		scope="singleton">
		<property name="address">
			<value>北京</value>
		</property>
	</bean>
	
	<!-- 配置bean  相同类型只能在 配置文件中出现一次
	<bean id="homeAddressServiceImpl" class="cn.csdn.service.HomeAddressServiceImpl" scope="prototype">
	  <property name="address">
	    <value>北京</value>	    
	  </property>
	</bean>
	-->
	
	<!-- 自动装配 采用constructor 构造器中的参数是按照byType进行装配的 -->
	<bean id="empServiceImpl" class="cn.csdn.service.EmpServiceImpl" scope="singleton" autowire="constructor"/>
</beans>