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.