Spring实战之调用实例工厂方法创建Bean操作示例

<?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">
   <!-- 配置工厂Bean,该Bean负责产生其他Bean实例 -->
   <bean id="personFactory" class="org.crazyit.app.factory.PersonFactory"/>
   <!-- 下面配置驱动Spring调用personFactory Bean的getPerson()方法来创建Bean
   该bean元素包含的constructor-arg元素用于为工厂方法指定参数，
   因此这段配置会驱动Spring以反射方式来执行如下代码：
   PersonFactory pf = container.get("personFactory"); // container代表Spring容器
   chinese = pf.getPerson("chin"); -->
   <bean id="chinese" factory-bean="personFactory"
      factory-method="getPerson">
      <!-- 配置实例工厂方法的参数 -->
      <constructor-arg value="chin"/>
   </bean>
   <!-- 下面配置会驱动Spring以反射方式来执行如下代码：
   PersonFactory pf = container.get("personFactory"); // container代表Spring容器
   american = pf.getPerson("ame"); -->
   <bean id="american" factory-bean="personFactory"
      factory-method="getPerson">
      <constructor-arg value="ame"/>
   </bean>
</beans>

package org.crazyit.app.service;
public interface Person
{
   // 定义一个打招呼的方法
   public String sayHello(String name);
   // 定义一个告别的方法
   public String sayGoodBye(String name);
}

public class American implements Person
{
   // 实现Person接口必须实现如下两个方法
   public String sayHello(String name)
   {
      return name + ",Hello!";
   }
   public String sayGoodBye(String name)
   {
      return name + ",Good Bye!";
   }
}

package org.crazyit.app.service.impl;
import org.crazyit.app.service.*;
public class Chinese implements Person
{
   // 实现Person接口必须实现如下两个方法
   public String sayHello(String name)
   {
      return name + "，您好";
   }
   public String sayGoodBye(String name)
   {
      return name + "，下次再见";
   }
}

package org.crazyit.app.factory;
import org.crazyit.app.service.*;
import org.crazyit.app.service.impl.*;
public class PersonFactory
{
  // 获得Person实例的实例工厂方法
  // ethnic参数决定返回哪个Person实现类的实例
  public Person getPerson(String ethnic)
  {
    if (ethnic.equalsIgnoreCase("chin"))
    {
      return new Chinese();
    }
    else
    {
      return new American();
    }
  }
}

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)
  {
    ApplicationContext ctx = new
      ClassPathXmlApplicationContext("beans.xml");
    Person p1 = ctx.getBean("chinese"
      , Person.class);
    System.out.println(p1.sayHello("Mary"));
    System.out.println(p1.sayGoodBye("Mary"));
    Person p2 = ctx.getBean("american"
      , Person.class);
    System.out.println(p2.sayHello("Jack"));
    System.out.println(p2.sayGoodBye("Jack"));
  }
}