1.整合spring+hibernate中，让spring接管hibernate的session工厂有一段代码
[
java]
<bean id="sFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
查看源码：org.springframework.orm.hibernate3.LocalSessionFactoryBean:
[
java]
public class LocalSessionFactoryBean extends AbstractSessionFactoryBean implements BeanClassLoaderAware
在到AbstractSessionFactoryBean:
[
java]
public abstract class AbstractSessionFactoryBean
implements FactoryBean<SessionFactory>, InitializingBean, DisposableBean, PersistenceExceptionTranslator
发现了实现了一个factoryBean<T>,里面给了个泛型(SeesionFactory).
注：这个bean和其他的bean不一样,spring中有两种bean.
普通bean和bean工厂,即FactoryBean. FactoryBean 返回的不是这个类的实例，其返回的是该工厂Bean的getObject()方法所返回的对象
普通的Bean直接返回指定类(配置中的class属性的值)的一个实例.
一个小例子：
[
java]
package org.ymm.entity;
import org.springframework.beans.factory.FactoryBean;
/**
* TestBean 类实现了FactoryBean<T>
* @author witho_000
*
*/
public class TestBean implements FactoryBean<Object>{
public Object getObject() throws Exception {
// TODO Auto-generated method stub
return "string类型";
}
@Override
public Class<?> getObjectType() {
// TODO Auto-generated method stub
return null;
}
@Override
public boolean isSingleton() {
// TODO Auto-generated method stub
return false;
}
}
[
java]
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsichemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.sprinsgframework.org/schema/context/spring-context-3.0.xsd">
<!-- 测试factorybean -->
<bean id="factorybean1" class="org.ymm.entity.TestBean" />
</beans>
[
java]
package org.ym.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.ymm.entity.TestBean;
/**
* Tester测试类
* @author witho_000
*
*/
public class Tester {
public static void main(String[] args) {
ApplicationContext cont=new ClassPathXmlApplicationContext("beans.xml");
String s= cont.getBean(";factorybean1",String.class);
System.out.println(s.getClass());
}
}
显然没有报错，返回的正是String类型。而不是spring配置的TestBean类型;
网上找到的小技巧：
String s= cont.getBean(";factorybean1",String.class);
bean的id前加个;得到的就是TestBean
作者:without0815
