三种实例化bean的方式

1.使用类构造器实例化
<bean id=“orderService" class="cn.itcast.OrderServiceBean"/>

2.使用静态工厂方法实例化
<bean id="persionServiceBean2" class="cn.com.xinli.service.impl.PersionServiceBeanFactory" factory-method="createPersionServiceBean"/>

public class PersionServiceBeanFactory
{
 public static PersionServiceBean createPersionServiceBean()
 {
  return new PersionServiceBean();
 }
}

例子:

(1).首先写工厂类.他其中包含产生我们的业务bean的方法

Java代码

1. package cn.com.xinli.service.impl;   
2.   
3.   
4. public class PersionServiceBeanFactory   
5. {   
6.     public static PersionServiceBean createPersionServiceBean()   
7.     {   
8.         return new PersionServiceBean();   
9.     }   
10. }  

package cn.com.xinli.service.impl;
public class PersionServiceBeanFactory
{
public static PersionServiceBean createPersionServiceBean()
{
return new PersionServiceBean();
}
}

(2).改写beans.xml :包含工厂类类名和产生业务bean的方法名字

 <bean id="persionServiceBean2" class="cn.com.xinli.service.impl.PersionServiceBeanFactory" factory-method="createPersionServiceBean"/>

 (3) 测试

Java代码

1. ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");   
2.         PersionSevice ps=(PersionSevice)ctx.getBean("persionServiceBean2");   
3.                                                         
4.         ps.save();  

ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
PersionSevice ps=(PersionSevice)ctx.getBean("persionServiceBean2");
ps.save();

 (4) 结果

2009-05-24 14:34:00,781  INFO (PersionServiceBean.java:12) - 我是save()方法!

3.使用实例工厂方法实例化:

<bean id="PersionServiceBeanFactory" class="cn.com.xinli.service.impl.PersionServiceBeanFactory"></bean>
    <bean id="persionServiceBean3" factory-bean="PersionServiceBeanFactory" factory-method="createPersionServiceBean2"></bean>

public  PersionServiceBean createPersionServiceBean2()
 {
  return new PersionServiceBean();
 }

例子:

(1). 首先写工厂类.他其中包含产生我们的业务bean的方法 ,在已有代码的基础上

Java代码

1. package cn.com.xinli.service.impl;   
2.   
3.   
4. public class PersionServiceBeanFactory   
5. {   
6.     public static PersionServiceBean createPersionServiceBean()   
7.     {   
8.         return new PersionServiceBean();   
9.     }   
10.        
11.     <SPAN style="COLOR: #ff0000">public  PersionServiceBean createPersionServiceBean2()   
12.     {   
13.         return new PersionServiceBean();   
14.     }</SPAN>   
15.        
16. }  

package cn.com.xinli.service.impl;
public class PersionServiceBeanFactory
{
public static PersionServiceBean createPersionServiceBean()
{
return new PersionServiceBean();
}
public  PersionServiceBean createPersionServiceBean2()
{
return new PersionServiceBean();
}
}

(2).改写beans.xml :写两个bean,一个是工厂bean,一个是利用工厂bean产生业务bean的bean.

Xml代码

1. <bean id="PersionServiceBeanFactory" class="cn.com.xinli.service.impl.PersionServiceBeanFactory"></bean>  
2.     <bean id="persionServiceBean3" factory-bean="PersionServiceBeanFactory" factory-method="createPersionServiceBean2"></bean>  

<bean id="PersionServiceBeanFactory" class="cn.com.xinli.service.impl.PersionServiceBeanFactory"></bean>
<bean id="persionServiceBean3" factory-bean="PersionServiceBeanFactory" factory-method="createPersionServiceBean2"></bean>

 (3) 测试

Java代码

1. ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");   
2.         PersionSevice ps=(PersionSevice)ctx.getBean("persionServiceBean3");   
3.                                                         
4.         ps.save();  

ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
PersionSevice ps=(PersionSevice)ctx.getBean("persionServiceBean3");
ps.save();

 (4) 结果

2009-05-24 14:49:17,812  INFO (PersionServiceBean.java:12) - 我是save()方法!

 (5) 注意,其实方式2和方式3的区别就在 工厂类中是如何产生业务bean的,方式2是static方式,方式3不是