javax.servlet.jsp.tagext
Class TagSupport


java.lang.Object

  |

  +--javax.servlet.jsp.tagext.TagSupport

Direct Known Subclasses:
BodyTagSupport

public class TagSupport
extends java.lang.Object
implements Tag, java.io.Serializable

Actions in a Tag Library are defined through subclasses of Tag.

See Also:
Serialized Form

Field Summary
protected  java.lang.String id
           
protected  PageContext pageContext
           
 
Constructor Summary
TagSupport()
          Default constructor, all subclasses are required to only define a public constructor with the same signature, and to call the superclass constructor.
 
Method Summary
 int doEndTag()
          Process the end tag.
 int doStartTag()
          Process the start tag for this instance.
static Tag findAncestorWithClass(Tag from, java.lang.Class klass)
          Find the instance of a given class type that is closest to a given instance.
 java.lang.String getId()
          The value of the id attribute of this tag; or null.
 Tag getParent()
          The Tag instance enclosing this tag instance.
 java.lang.Object getValue(java.lang.String k)
          Get a value
 java.util.Enumeration getValues()
          Enumerate the values
 void release()
          release() called after doEndTag() to reset state
 void removeValue(java.lang.String k)
          Remove a value
 void setId(java.lang.String id)
          Set the id attribute
 void setPageContext(PageContext pageContext)
          set the page context
 void setParent(Tag t)
          Set the nesting tag of this tag.
 void setValue(java.lang.String k, java.lang.Object o)
          Set a value
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

id


protected java.lang.String id

pageContext


protected PageContext pageContext
Constructor Detail

TagSupport


public TagSupport()
Default constructor, all subclasses are required to only define a public constructor with the same signature, and to call the superclass constructor. This constructor is called by the code generated by the JSP translator.
Parameters:
libraryPrefix - The namespace prefix used for this library. For example "jsp:".
tagName - The name of the element or yag, for example "useBean"
Method Detail

findAncestorWithClass


public static final Tag findAncestorWithClass(Tag from,

                                              java.lang.Class klass)
Find the instance of a given class type that is closest to a given instance. This class is used for coordination among cooperating tags.
Parameters:
the - subclass of Tag or interface to be matched
Returns:
the nearest ancestor that implements the interface or is an instance of the class specified

doStartTag


public int doStartTag()

               throws JspException
Process the start tag for this instance. The doStartTag() method assumes that all setter methods have been invoked before. When this method is invoked, the body has not yet been invoked.
Specified by:
doStartTag in interface Tag

doEndTag


public int doEndTag()

             throws JspException
Process the end tag. This method will be called on all Tag objects. All instance state associated with this instance must be reset.
Specified by:
doEndTag in interface Tag

release


public void release()
release() called after doEndTag() to reset state
Specified by:
release in interface Tag

setParent


public void setParent(Tag t)
Set the nesting tag of this tag.
Specified by:
setParent in interface Tag

getParent


public Tag getParent()
The Tag instance enclosing this tag instance.
Specified by:
getParent in interface Tag
Returns:
the parent tag instance or null

setId


public void setId(java.lang.String id)
Set the id attribute

getId


public java.lang.String getId()
The value of the id attribute of this tag; or null.
Returns:
the value of the id attribute, or null

setPageContext


public void setPageContext(PageContext pageContext)
set the page context
Specified by:
setPageContext in interface Tag

setValue


public void setValue(java.lang.String k,

                     java.lang.Object o)
Set a value

getValue


public java.lang.Object getValue(java.lang.String k)
Get a value

removeValue


public void removeValue(java.lang.String k)
Remove a value

getValues


public java.util.Enumeration getValues()
Enumerate the values