使用PIG中的xpath在XML中提取属性值

<Type>  
    <Source>        
        <TimeStamp>2016-02-19T12:27:06.387Z</TimeStamp>
        <IPAddress IPVersion="IPv4">x.xx.xxx.xxx</IPAddress>
        <Port>64435</Port>
        <DNS_Name>x.xx.xxx.xxx.range9-27.abc.com</DNS_Name>
    </Source>
 </Type>

我正在尝试使用下面的代码从上面的标签中检索所有值.

REGISTER piggybank-0.15.0.jar
            DEFINE XPath org.apache.pig.piggybank.evaluation.xml.XPath();

        A =  LOAD 'test.xml' using org.apache.pig.piggybank.storage.XMLLoader('Type') as (x:chararray);
        B = FOREACH A GENERATE 
                               XPath(x, 'Source/TimeStamp')
                               ,XPath(x, 'Source/IPAddress')
                               ,XPath(x, 'Source/IPAddress/@IPVersion')
                               ,XPath(x, 'Source/Port')
                               ,XPath(x, 'Source/DNS_Name');

当我转储B时,我得到以下输出,其中缺少IPVersion的值.

(2016-02-19T12:27:06.387Z,x.xx.xxx.xxx,,64435,x.xx.xxx.xxx.range9-27.abc.com)

有谁可以帮我解决这个问题？

> ignoreNamespace逻辑中断了对XML属性的搜索
https://issues.apache.org/jira/browse/PIG-4751
> ignoreNamepace参数默认为true且无法覆盖
https://issues.apache.org/jira/browse/PIG-4752

看看XPathAll here的解决方法