Package jakarta.servlet.jsp.tagext

Class TagData

java.lang.Object

jakarta.servlet.jsp.tagext.TagData

All Implemented Interfaces:

Cloneable

public class TagData
extends Object
implements 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.

Field Summary

Fields

Modifier and Type	Field	Description
static final Object	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).

Constructor Summary

Constructors

Constructor	Description
TagData(Object[][] atts)	Constructor for TagData.
TagData(Hashtable<String,Object> attrs)	Constructor for a TagData.

Method Summary

Modifier and Type	Method	Description
Object	getAttribute(String attName)	The value of the attribute.
Enumeration<String>	getAttributes()	Enumerates the attributes.
String	getAttributeString(String attName)	Get the value for a given attribute.
String	getId()	The value of the tag's id attribute.
void	setAttribute(String attName, Object value)	Set the value of an attribute.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

REQUEST_TIME_VALUE

public static final Object 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).

Constructor Details

TagData

public TagData(Object[][] atts)

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.

TagData

public TagData(Hashtable<String,Object> attrs)

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.

Method Details

getId

public String 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.

getAttribute

public Object getAttribute(String attName)

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

setAttribute

public void setAttribute(String attName,
 Object value)

Set the value of an attribute.

Parameters:

attName - the name of the attribute

value - the value.

getAttributeString

public String getAttributeString(String attName)

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

getAttributes

public Enumeration<String> getAttributes()

Enumerates the attributes.

Returns:

An enumeration of the attributes in a TagData