DWR 和 OpenSessionInViewFilter

项目中使用了Spring的OpenSessionInViewFilter，使得Hibernate的延时加载很方便，同时我也把DWR影射进取了，代码如下。

    <filter></filter>
        <filter-name></filter-name>hibernateFilter
        <filter-class></filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter
        <init-param></init-param>
    <param-name></param-name> singleSession
    <param-value></param-value> true
  
   

    <filter-mapping></filter-mapping>
        <filter-name></filter-name>securityFilter
        <url-pattern></url-pattern>/*
   

 

这样DWR就不会抱延时加载的错误了，但是它在把javaBean转换成JS的时候，调用了所有的Bean中的Get方法，这样Hibernate就把所有和这关联的属性都加载进来了，这样效率自然变低了，尤其是在加载Set的时候，一对多的时候，很慢，经常出错。，。。。。。。。。。

以上是我猜想的错误，就这样我想到修改源代码，个人适用的DWR版本是

Manifest-Version: 1.0
Ant-Version: Apache Ant 1.6.5
Created-By: 1.5.0_07-87 ("Apple Computer, Inc.")

把其中的org.directwebremoting.convert.CollectionConverter文件下这个方法修改为

 这样可以不加载Set了，其他属性还是加载，因为平时需要用到其他属性。

完成。。。。OK

public OutboundVariable convertOutbound(Object data, OutboundContext outctx) throws MarshallException
    {
        // Where we collect out converted children
        Map ovs = new TreeMap();

        // We need to do this before collecing the children to save recurrsion
        ObjectOutboundVariable ov = new ObjectOutboundVariable(outctx);
        outctx.put(data, ov);

        try
        {
            Map properties = getPropertyMapFromObject(data, true, false);
            for (Iterator it = properties.entrySet().iterator(); it.hasNext();)
            {
                Map.Entry entry = (Map.Entry) it.next();
                String name = (String) entry.getKey();
                Property property = (Property) entry.getValue();

                Object value = property.getValue(data);
                //如果为Set跳过------------------------------------------------
                if(value!=null&&value.getClass()==org.hibernate.collection.PersistentSet.class){
                    continue;
               
                }OutboundVariable nested = getConverterManager().convertOutbound(value, outctx);

                ovs.put(name, nested);
            }
        }
        catch (MarshallException ex)
        {
            throw ex;
        }
        catch (Exception ex)
        {
            throw new MarshallException(data.getClass(), ex);
        }

        ov.init(ovs, getJavascript());

        return ov;
    }

评论

1 楼 yelongkun 2007-07-10  

搞点简单的不好呀,看不懂呀