Spring bean inheritance bean 继承

Bean definition inheritance

定义一个基类：

package com.myapp.core.inherit;

public class Father {
	 private  String name;
	 private  int  age;
	 private  String  type;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	
	public  String  toString(){
		return  "["+name+","+age+","+type+"]";
	}
	 
}

对应的xml配置文件：

<!-- show the  bean  inheritance  just  see  the  following  setting -->
   
   <bean id="father" class="com.myapp.core.inherit.Father" >
     <property name="name" value="tom"> </property>
     <property name="age" value="50"></property>
   </bean>
   
   <bean id="son" parent="father">
    <property name="age" value="24"></property>
    <property name="type" value="child"></property>
   </bean>

对应的测试类：

package com.myapp.core.inherit;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainTest {
   public static void main(String[] args) {
	 ApplicationContext  context = new  ClassPathXmlApplicationContext("SpringBeans.xml");
	 
	 Father    son  = (Father)context.getBean("son");
	 
	 //Father    father  = (Father)context.getBean("father");
	 
	 
	 System.out.println(son);
}
}

输出结果：

[tom,24,child]

如果需要把基类定义为模板 需要在基类中加入 abstract="true" 属性

修改后为：

<span style="font-size:10px;">  
   <!-- show the  bean  inheritance  just  see  the  following  setting -->
   
   <bean id="father" class="com.myapp.core.inherit.Father" abstract="true" >
     <property name="name" value="tom"> </property>
     <property name="age" value="50"></property>
   </bean>
   
   <bean id="son" parent="father">
    <property name="age" value="24"></property>
    <property name="type" value="child"></property>
   </bean>
   

</span>

定义为抽象的基类不能再获取对象了，因为不可实例化，

 Father    father  = (Father)context.getBean("father");

如果实例化会报如下异常：

Exception in thread "main" org.springframework.beans.factory.BeanIsAbstractException: Error creating bean with name 'father': Bean definition is abstract