我正在尝试使用在for循环中调用的方法从节点中提取值。
每次调用Method时,xpath.evaluate仅计算首次传入方法的原始节点。
- 示例节点
<doc>
<str name="subcategory">xyzabc</str>
<str name="type">QAs</str>
<str name="id">1234</str>
</doc>
- 用于调用的循环
ArrayList<Node> responseNodeList = parseResponse(*document as string*);
for(int k = 0;k<responseNodeList.size();k++){
Result resultNode = new Result();
resultNode.setUrl(new URL(getAttributeValue(responseNodeList.get(k),resultUrl)));
resultNode.setId(new String(getAttributeValue(responseNodeList.get(k),resultId)));
}
- 我提取值的方法
private String getAttributeValue(final Node responseNodeUrl, String attribute) throws SearchException {
try {
Node evalNode = null;
evalNode = responseNodeUrl;
try {
nodelisttostr(responseNodeUrl); // This is what i am printing out the node.. where we dont have a problem
} catch (TransformerFactoryConfigurationError e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
XPath xPath = XPathFactory.newInstance().newXPath();
XPathExpression expr = null;
expr = xPath.compile("/doc/str[@name='"+attribute+"']");
String result ;
result=(String) expr.evaluate(evalNode,XPathConstants.STRING);
xPath.reset();
System.out.println("++++++++"+result); //But when i print this out, it always prints the same value
return result;
} catch (XPathExpressionException e) {
log.error("Error in SearchEngine:getAttributeValue:: "+e.getMessage());
throw new SearchException(e);
}
}
答案 0 :(得分:0)
解决..
XpathExpression总是拿起传递给该方法的第一个节点,由于某种原因,它似乎被缓存了,我将我的评估字符串改为看起来像expr = xPath.compile(".//str[@name='"+attribute+"']");
,然后评估方法现在将当前视图文档。
谢谢大家。
答案 1 :(得分:-1)
如果在上面的XML上,您使用:
Thing
你会得到:
// Create a `ThingBase` class to "type-erase" `Thing`'s
// template parameter. `ThingBase` should contain your
// `func`, as `virtual`.
struct ThingBase
{
virtual void func();
};
// Your `Thing<T>` class should override `func`
template <typename T>
struct Thing : ThingBase
{
void func() override { /* ... */ }
};
// Your `IService` now only needs to be as follows:
struct IService
{
void func(ThingBase& x)
{
x.func();
}
};
如果您在XML上面的XPath表达式中使用//doc/str/@name
,即
Attribute='name="subcategory"'
Attribute='name="type"'
Attribute='name="id"'
然后你会得到:
contains
但我认为您只想用您的代码执行以下操作:
改变这个:
//doc/str/@name[contains(.,'e')]
即可添加额外的Attribute='name="subcategory"'
Attribute='name="type"'
:
expr = xPath.compile("/doc/str[@name='"+attribute+"']");
评估所有节点而不是第一个节点。
我希望这有帮助!