Could someone please help me undertand what this method does.
This is what the API docs say, but I cannot make head or tail of it (slow-brain-monday perhaps)
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findAncestorWithClass
public static final JspTag findAncestorWithClass(JspTag from, java.lang.Class<?> klass)
Find the instance of a given class type that is closest to a given instance. This method uses the getParent method from the Tag and/or SimpleTag interfaces. This method is used for coordination among cooperating tags.
For every instance of TagAdapter encountered while traversing the ancestors, the tag handler returned by TagAdapter.getAdaptee() - instead of the TagAdpater itself - is compared to klass. If the tag handler matches, it - and not its TagAdapter - is returned.
The current version of the specification only provides one formal way of indicating the observable type of a tag handler: its tag handler implementation class, described in the tag-class subelement of the tag element. This is extended in an informal manner by allowing the tag library author to indicate in the description subelement an observable type. The type should be a subtype of the tag handler implementation class or void. This addititional constraint can be exploited by a specialized container that knows about that specific tag library, as in the case of the JSP standard tag library.
When a tag library author provides information on the observable type of a tag handler, client programmatic code should adhere to that constraint. Specifically, the Class passed to findAncestorWithClass should be a subtype of the observable type.
Parameters:
from - The instance from where to start looking.
klass - The subclass of JspTag or interface to be matched
Returns:
the nearest ancestor that implements the interface or is an instance of the class specified
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