抽象工程、单例

用spring获取bean违例
1：定义工程接口
package com.spdx.app.proxy;


public interface IBeanFactory
{
    public Object createBean(String beanName);
}

2：定义抽象工程，实现单例
public abstract class AbstractBeanFactory implements IBeanFactory
{
   
    private static String className = "com.spdx.app.proxy.SimpleBeanFactory";
   
    private static Object lock = new Object();
   
    private static AbstractBeanFactory instance;
   
    public static AbstractBeanFactory getInstance()
    {
        if (null == instance)
        {
            synchronized (lock)
            {
                if (null == instance)
                {
                    try
                    {
                        Class clazz = Class.forName(className);
                        instance = (AbstractBeanFactory) clazz.newInstance();
                    }
                    catch (ClassNotFoundException e)
                    {
                    }
                    catch (InstantiationException e)
                    {
                    }
                    catch (IllegalAccessException e)
                    {
                    }
                }
            }
        }
        return instance;
    }
}

3：工厂实现

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;


public class SimpleBeanFactory extends AbstractBeanFactory
{

    private ApplicationContext application = null;
   
    private Resource resource = null;
   
    private BeanFactory beanFactory = null;
   
    public SimpleBeanFactory()
    {
        application = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
        application = new FileSystemXmlApplicationContext("src/applicationContext.xml");
       
        //resource = new ClassPathResource("applicationContext.xml");
        //beanFactory = new XmlBeanFactory(resource);
       
        System.out.println("init application...");
    }
   
    public Object createBean(String beanName)
    {
        return application.getBean(beanName);
        //return beanFactory.getBean(beanName);
    }
}