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 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