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

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

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

Tags copied from interface: Tag

See Also:

BodyTag

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