Spring学习笔记之Bean定义继承

若Bean定义文件内容很多,而且部分Bean的定义有重复,如属性相同,只有几个Bean有不同 的设置,则可以考虑继承某个Bean定义,好处多多:

People类


package com.nalis.spring;






public class People ...{


    private String name;




    private int age;






    public int getAge() ...{


        return age;


    }






    public void setAge(int age) ...{


        this.age = age;


    }






    public String getName() ...{


        return name;


    }






    public void setName(String name) ...{


        this.name = name;


    }


}



src目录下的beans.xml:


<?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-2.0.xsd">


    <bean id="inheritedPeople" abstract="true">


        <property name="name" value="guest" />


        <property name="age" value="18" />


    </bean>


    <bean id="temp1" class="com.nalis.spring.People"


        parent="inheritedPeople">


        <property name="name" value="nalis" />


        <property name="age" value="24" />


    </bean>


</beans>



测试类:BeaninheritedDemo

 


package com.nalis.spring;




import org.springframework.context.ApplicationContext;


import org.springframework.context.support.ClassPathXmlApplicationContext;






public class BeaninheritedDemo ...{








    public static void main(String[] args) ...{


        // TODO Auto-generated method stub


        ApplicationContext context = new ClassPathXmlApplicationContext(


                "beans.xml");


        People people = (People) context.getBean("temp1");


        System.out.println("name: " + people.getName());


        System.out.println("age: " + people.getAge());


    }




}

此上是完全抽象的Bean定义继承,还可以从一个Bean实例的定义中继承


<bean id="people" class="com.nalis.spring.People">


        <property name="name" value="zhang3" />


        <property name="age" value="44" />


</bean>




<bean id="temp2" class="com.nalis.spring.People"    parent="people">


        <property name="name" value="li4" />


        


</bean>

此例"people"已经实例化,若有必要,可用其他Bean(如"temp2")继承其定义.