XPath and XML

Question

I have an xml file
<?xml version='1.0' encoding='UTF-8'?>
<myBook>
<friend>
<name>Smith</name>
<Address>NY</Address>
<Birthday year='1976' month='12' day='23' />
</friend>
</myBook>
Now I am writing a java application to access different Nodes of this xml file as per required. For example the query for a friend with birthday 09/22/76 will be
//myBook/Birthday[@year = '76' and month = '09' and day = '22']
and it works. But I am stuck with what if I want to get info of friends with birthdays between 06/23/78 and 09/16/78.
Any ideas and help would be greatly appreciated.
Thanx

Answer 1

You can (and probably should) deal with this type of decision making using Java instead of XPath due to performance reasons. However, if you must deal with it using XPath, here is a sample.
Assume that you have the following XML document fragment:
<myBook>
<friend>
<name>Smith</name>
<Birthday year='1976' month='06' day='15' />
</friend>
<friend>
<name>Joe</name>
<Birthday year='1976' month='06' day='23' />
</friend>
<friend>
<name>Bill</name>
<Birthday year='1976' month='09' day='15' />
</friend>
<friend>
<name>Bill</name>
<Birthday year='1976' month='09' day='21' />
</friend>
</myBook>
The following XPath query will return the nodes that contains friend nodes where the month is between 6 and 9.
XPath:
//friend/Birthday[(@month>'5')][(@month <'10')]/parent::*
Result:
<friend>
     <name>Smith</name>
     <Birthday year="1976" month="06" day="15" />
</friend>
<friend>
     <name>Joe</name>
     <Birthday year="1976" month="06" day="23" />
</friend>
<friend>
     <name>Bill</name>
     <Birthday year="1976" month="09" day="15" />
</friend>
<friend>
     <name>Bill</name>
     <Birthday year="1976" month="09" day="21" />
</friend>
Then you have to look at each returned node and decide whether to accept it or reject.
Note: You have to use & to escape "<" and ">" in the XPath as the comparison operator