DWR在和spring集成时的bug,SpringCreator.getType???

DWR在和spring集成时,在dwr.xml中将设置creator="spring",告诉dwr将使用dwr的org.directwebremoting.spring.SpringCreator来创建对象实例,但是SpringCreator.getType地处理是不适当的,让我们来看看它的源码[dwr-3.0.0.116]:

public Class<?> getType()
    {
        if (clazz == null)
        {
            try
            {
                clazz = getInstance().getClass();
            }
            catch (InstantiationException ex)
            {
                log.error("Failed to instansiate object to detect type.", ex);
                return Object.class;
            }
        }

        return clazz;
    }

我们再来看看它的getInstance,最终由spring来创建实例.

public Object getInstance() throws InstantiationException
    {
        try
        {
            if (overrideFactory != null)
            {
                return overrideFactory.getBean(beanName);
            }

            if (factory == null)
            {
                factory = getBeanFactory();
            }

            if (factory == null)
            {
                log.error("DWR can't find a spring config. See following info logs for solutions");
                log.info("- Option 1. In dwr.xml, <create creator='spring' ...> add <param name='location1' value='beans.xml'/> for each spring config file.");
                log.info("- Option 2. Use a spring org.springframework.web.context.ContextLoaderListener.");
                log.info("- Option 3. Call SpringCreator.setOverrideBeanFactory() from your web-app");
                throw new InstantiationException("DWR can't find a spring config. See the logs for solutions");
            }

            return factory.getBean(beanName);
        }
        catch (InstantiationException ex)
        {
            throw ex;
        }
        catch (Exception ex)
        {
            throw new InstantiationException("Illegal Access to default constructor on " + clazz.getName() + " due to: " + ex);
        }
    }

getInstance将返回由spring来创建的实例,很明显SpringCreator.getType有点多此一举,它先创建了实例,再从实例的getClass获取对象的类型,而spring的beanFactory.getType同样有此功能,但它不需要先创建实例.

也许写这位代码的仁兄是不知道spring beanFactory.getType这个方法吧!

我把SpringCreator.getType改正后的代码 如下:

public Class<?> getType()
    {
        if (clazz == null)
        {
            try
            {
                if(overrideFactory != null){
                    clazz=overrideFactory.getType(beanName);
                }else {
                    if(factory == null)
                       factory = getBeanFactory();
                    clazz=factory.getType(beanName);
                }               
            }
            catch (Exception ex)
            {
                log.error("Failed to detect type.", ex);
                return Object.class;
            }
        }

        return clazz;
    }

 

如果出现 Error loading class for creator ...... 那么就修改SpringCreator吧!