org.xml.sax.helpers.AttributeListImpl Maven / Gradle / Ivy
// SAX default implementation for AttributeList.
// No warranty; no copyright -- use this as you will.
// $Id: AttributeListImpl.java,v 1.1 1999/02/26 21:32:46 mode Exp $
package org.xml.sax.helpers;
import org.xml.sax.AttributeList;
import java.util.Vector;
/**
* Convenience implementation for AttributeList.
*
* This class provides a convenience implementation of the SAX
* AttributeList class. This implementation is useful both
* for SAX parser writers, who can use it to provide attributes
* to the application, and for SAX application writers, who can
* use it to create a persistent copy of an element's attribute
* specifications:
*
*
* private AttributeList myatts;
*
* public void startElement (String name, AttributeList atts)
* {
* // create a persistent copy of the attribute list
* // for use outside this method
* myatts = new AttributeListImpl(atts);
* [...]
* }
*
*
* Please note that SAX parsers are not required to use this
* class to provide an implementation of AttributeList; it is
* supplied only as an optional convenience. In particular,
* parser writers are encouraged to invent more efficient
* implementations.
*
* @author David Megginson ([email protected])
* @version 1.0
* @see org.xml.sax.AttributeList
* @see org.xml.sax.DocumentHandler#startElement
*/
public class AttributeListImpl implements AttributeList
{
/**
* Create an empty attribute list.
*
* This constructor is most useful for parser writers, who
* will use it to create a single, reusable attribute list that
* can be reset with the clear method between elements.
*
* @see #addAttribute
* @see #clear
*/
public AttributeListImpl ()
{
}
/**
* Construct a persistent copy of an existing attribute list.
*
* This constructor is most useful for application writers,
* who will use it to create a persistent copy of an existing
* attribute list.
*
* @param atts The attribute list to copy
* @see org.xml.sax.DocumentHandler#startElement
*/
public AttributeListImpl (AttributeList atts)
{
setAttributeList(atts);
}
//////////////////////////////////////////////////////////////////////
// Methods specific to this class.
//////////////////////////////////////////////////////////////////////
/**
* Set the attribute list, discarding previous contents.
*
* This method allows an application writer to reuse an
* attribute list easily.
*
* @param atts The attribute list to copy.
*/
public void setAttributeList (AttributeList atts)
{
int count = atts.getLength();
clear();
for (int i = 0; i < count; i++) {
addAttribute(atts.getName(i), atts.getType(i), atts.getValue(i));
}
}
/**
* Add an attribute to an attribute list.
*
* This method is provided for SAX parser writers, to allow them
* to build up an attribute list incrementally before delivering
* it to the application.
*
* @param name The attribute name.
* @param type The attribute type ("NMTOKEN" for an enumeration).
* @param value The attribute value (must not be null).
* @see #removeAttribute
* @see org.xml.sax.DocumentHandler#startElement
*/
public void addAttribute (String name, String type, String value)
{
names.addElement(name);
types.addElement(type);
values.addElement(value);
}
/**
* Remove an attribute from the list.
*
* SAX application writers can use this method to filter an
* attribute out of an AttributeList. Note that invoking this
* method will change the length of the attribute list and
* some of the attribute's indices.
*
* If the requested attribute is not in the list, this is
* a no-op.
*
* @param name The attribute name.
* @see #addAttribute
*/
public void removeAttribute (String name)
{
int i = names.indexOf(name);
if (i >= 0) {
names.removeElementAt(i);
types.removeElementAt(i);
values.removeElementAt(i);
}
}
/**
* Clear the attribute list.
*
* SAX parser writers can use this method to reset the attribute
* list between DocumentHandler.startElement events. Normally,
* it will make sense to reuse the same AttributeListImpl object
* rather than allocating a new one each time.
*
* @see org.xml.sax.DocumentHandler#startElement
*/
public void clear ()
{
names.removeAllElements();
types.removeAllElements();
values.removeAllElements();
}
//////////////////////////////////////////////////////////////////////
// Implementation of org.xml.sax.AttributeList
//////////////////////////////////////////////////////////////////////
/**
* Return the number of attributes in the list.
*
* @return The number of attributes in the list.
* @see org.xml.sax.AttributeList#getLength
*/
public int getLength ()
{
return names.size();
}
/**
* Get the name of an attribute (by position).
*
* @param i The position of the attribute in the list.
* @return The attribute name as a string, or null if there
* is no attribute at that position.
* @see org.xml.sax.AttributeList#getName(int)
*/
public String getName (int i)
{
try {
if (i < 0) return null;
return (String)names.elementAt(i);
} catch (ArrayIndexOutOfBoundsException e) {
return null;
}
}
/**
* Get the type of an attribute (by position).
*
* @param i The position of the attribute in the list.
* @return The attribute type as a string ("NMTOKEN" for an
* enumeration, and "CDATA" if no declaration was
* read), or null if there is no attribute at
* that position.
* @see org.xml.sax.AttributeList#getType(int)
*/
public String getType (int i)
{
try {
if (i < 0) return null;
return (String)types.elementAt(i);
} catch (ArrayIndexOutOfBoundsException e) {
return null;
}
}
/**
* Get the value of an attribute (by position).
*
* @param i The position of the attribute in the list.
* @return The attribute value as a string, or null if
* there is no attribute at that position.
* @see org.xml.sax.AttributeList#getValue(int)
*/
public String getValue (int i)
{
try {
if (i < 0) return null;
return (String)values.elementAt(i);
} catch (ArrayIndexOutOfBoundsException e) {
return null;
}
}
/**
* Get the type of an attribute (by name).
*
* @param name The attribute name.
* @return The attribute type as a string ("NMTOKEN" for an
* enumeration, and "CDATA" if no declaration was
* read).
* @see org.xml.sax.AttributeList#getType(java.lang.String)
*/
public String getType (String name)
{
return getType(names.indexOf(name));
}
/**
* Get the value of an attribute (by name).
*
* @param name The attribute name.
* @see org.xml.sax.AttributeList#getValue(java.lang.String)
*/
public String getValue (String name)
{
return getValue(names.indexOf(name));
}
//////////////////////////////////////////////////////////////////////
// Internal state.
//////////////////////////////////////////////////////////////////////
Vector names = new Vector();
Vector types = new Vector();
Vector values = new Vector();
}