Spring实战——协调作用域不同步的Bean

向右看齐 2021-07-24 21:03 255阅读 0赞

**一 配置**

<?xml version="1.0" encoding="GBK"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://www.springframework.org/schema/beans"
         xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
         <bean id="chinese"  class="org.crazyit.app.service.impl.Chinese">
               
               <lookup-method name="getDog" bean="gunDog"/>
         </bean>
         
         <bean id="gunDog"  class="org.crazyit.app.service.impl.GunDog"
               scope="prototype">
               <property name="name" value="旺财"/>
         </bean>
    </beans>

**二 接口**

1 Dog

package org.crazyit.app.service;
    
    public interface Dog
    {
         public String run();
    }

2 Person

package org.crazyit.app.service;
    
    public interface Person
    {
         public void hunt();
    }

**三 实现类**

GunDog

package org.crazyit.app.service.impl;
    import org.crazyit.app.service.*;
    
    public class GunDog implements Dog
    {
         private String name;
         public void setName(String name)
         {
               this.name = name;
         }
         public String getName()
         {
               return name;
         }
         public String run()
         {
               return "我是一只叫" + getName()
                    + "的猎犬，奔跑迅速..." ;
         }
    }

Chinese

package org.crazyit.app.service.impl;
    import org.crazyit.app.service.*;
    
    public abstract class Chinese implements Person
    {
         private Dog dog;
         // 定义抽象方法，该方法用于获取被依赖Bean
         public abstract Dog getDog();
         public void hunt()
         {
               System.out.println("我带着：" + getDog() + "出去打猎");
               System.out.println(getDog().run());
         }
    }

**四 测试类**

package lee;
    
    
    import org.springframework.context.*;
    import org.springframework.context.support.*;
    
    
    import org.crazyit.app.service.*;
    
    public class SpringTest
    {
        public static void main(String[] args)
        {
            // 以类加载路径下的beans.xml作为配置文件，创建Spring容器
            ApplicationContext ctx = new
                ClassPathXmlApplicationContext("beans.xml");
            Person p1 = ctx.getBean("chinese" , Person.class);
            Person p2 = ctx.getBean("chinese" , Person.class);
            // 由于chinese Bean是singleton行为，
            // 因此程序两次获取的chinese Bean是同一个实例。
            System.out.println(p1 == p2);
            p1.hunt();
            p2.hunt();
        }
    }

**五 测试结果**

true
    我带着：org.crazyit.app.service.impl.GunDog@69a3d1d出去打猎
    我是一只叫旺财的猎犬，奔跑迅速...
    我带着：org.crazyit.app.service.impl.GunDog@86be70a出去打猎
    我是一只叫旺财的猎犬，奔跑迅速...