Package javax.servlet.jsp.tagext
Class TagData
java.lang.Object
javax.servlet.jsp.tagext.TagData
- All Implemented Interfaces:
Cloneable
The (translation-time only) attribute/value information for a tag instance.
TagData is only used as an argument to the isValid, validate, and getVariableInfo methods of TagExtraInfo, which are invoked at translation time.
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Field Summary
Modifier and TypeFieldDescriptionstatic final Object
Distinguished value for an attribute to indicate its value is a request-time expression (which is not yet available because TagData instances are used at translation-time). -
Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptiongetAttribute
(String attName) The value of the attribute.Enumerates the attributes.getAttributeString
(String attName) Get the value for a given attribute.getId()
The value of the tag's id attribute.void
setAttribute
(String attName, Object value) Set the value of an attribute.
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Field Details
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REQUEST_TIME_VALUE
Distinguished value for an attribute to indicate its value is a request-time expression (which is not yet available because TagData instances are used at translation-time).
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Constructor Details
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TagData
Constructor for TagData.A typical constructor may be
static final Object[][] att = { { "connection", "conn0" }, { "id", "query0" } }; static final TagData td = new TagData(att);
All values must be Strings except for those holding the distinguished object REQUEST_TIME_VALUE.- Parameters:
atts
- the static attribute and values. May be null.
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TagData
Constructor for a TagData. If you already have the attributes in a hashtable, use this constructor.- Parameters:
attrs
- A hashtable to get the values from.
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Method Details
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getId
The value of the tag's id attribute.- Returns:
- the value of the tag's id attribute, or null if no such attribute was specified.
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getAttribute
The value of the attribute. If a static value is specified for an attribute that accepts a request-time attribute expression then that static value is returned, even if the value is provided in the body of a <jsp:attribute> action. The distinguished object REQUEST_TIME_VALUE is only returned if the value is specified as a request-time attribute expression or via the <jsp:attribute> action with a body that contains dynamic content (scriptlets, scripting expressions, EL expressions, standard actions, or custom actions). Returns null if the attribute is not set.- Parameters:
attName
- the name of the attribute- Returns:
- the attribute's value
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setAttribute
Set the value of an attribute.- Parameters:
attName
- the name of the attributevalue
- the value.
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getAttributeString
Get the value for a given attribute.- Parameters:
attName
- the name of the attribute- Returns:
- the attribute value string
- Throws:
ClassCastException
- if attribute value is not a String
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getAttributes
Enumerates the attributes.- Returns:
- An enumeration of the attributes in a TagData
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