/*
GASH 2
XMLITem.java
The Ganymede object storage system.
Created: 9 March 2000
Module By: Jonathan Abbey, jonabbey@arlut.utexas.edu
-----------------------------------------------------------------------
Ganymede Directory Management System
Copyright (C) 1996-2010
The University of Texas at Austin
Contact information
Web site: http://www.arlut.utexas.edu/gash2
Author Email: ganymede_author@arlut.utexas.edu
Email mailing list: ganymede@arlut.utexas.edu
US Mail:
Computer Science Division
Applied Research Laboratories
The University of Texas at Austin
PO Box 8029, Austin TX 78713-8029
Telephone: (512) 835-3200
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package arlut.csd.Util;
/*------------------------------------------------------------------------------
class
XMLItem
------------------------------------------------------------------------------*/
/**
* <P>Abstract base class for XML data held in the
* {@link arlut.csd.Util.XMLReader XMLReader} class's buffer.</P>
*
* <P>This class implements stubs for most of the methods
* in its subclass {@link arlut.csd.Util.XMLElement XMLElement}, so that
* the Ganymede server code can process elements without having to constantly
* perform cast operations. The matches() method returns false unless this
* XMLItem is actually an XMLElement with the appropriate label,
* and the matchesClose() method returns false unless this XMLItem is
* actually an {@link arlut.csd.Util.XMLCloseElement XMLCloseElement} with
* the appropriate label.</P>
*/
public abstract class XMLItem {
public XMLItem parent;
/* -- */
/**
* <P>This method returns the parent of this XMLItem, if any.</P>
*/
public XMLItem getParent()
{
return parent;
}
/**
* <P>This method returns an array of children under this item,
* or null if there are none.</P>
*/
public XMLItem[] getChildren()
{
return null;
}
/**
* <P>This method sets this XMLItem's parent.</P> */
public void setParent(XMLItem parent)
{
this.parent = parent;
}
/**
* <P>This method sets an array of XMLItem references to be
* this XMLItem's children.</P>
*/
public void setChildren(XMLItem[] children)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method unlinks this XMLItem and any subnodes of
* it from each other, as well as clearing this XMLItem's
* parent reference. After this is called, children
* and parent will both be null-valued.</P>
*/
public void dissolve()
{
parent = null;
}
/**
* <P>This method returns true if this item is an
* {@link arlut.csd.Util.XMLElement XMLElement} named
* <name>, false otherwise.</P>
*/
public boolean matches(String name)
{
return false;
}
/**
* <P>This method returns true if this item is an
* {@link arlut.csd.Util.XMLCloseElement XMLCloseElement} named
* <name>, false otherwise.</P>
*/
public boolean matchesClose(String name)
{
return false;
}
/**
* <P>This method returns true if this is an empty element.</P>
*/
public boolean isEmpty()
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns true if this is an open element.</P>
*/
public boolean isOpen()
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the number of attributes that this
* element has.</P>
*/
public int getAttrCount()
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <p>This method returns the name for a given attribute
* in this XMLItem.</p>
*/
public String getAttrKey(int index)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <p>This method returns the value for a given attribute
* in this XMLItem.</p>
*/
public String getAttrVal(int index)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the attribute value for attribute
* <name>, if any. If this element does not contain
* an attribute of the given name, null is returned.</P>
*/
public String getAttrStr(String name)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the boolean attribute value for attribute
* <name>, if any. For Ganymede's purposes, an attribute
* value is true if the attribute is present with a string
* value of "1". If this element does not contain
* an attribute of the given name, false is returned.</P>
*/
public boolean getAttrBoolean(String name)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the Integer attribute value for attribute
* <name>, if any. If this element does not contain
* an attribute of the given name, or if the attribute does not
* contain an integer value, a null value is returned.</P>
*/
public Integer getAttrInt(String name)
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the name of an element, if this is
* the right kind of item.</P>
*/
public String getName()
{
throw new IllegalArgumentException("not an XMLElement.");
}
/**
* <P>This method returns the character data for this XMLItem.</P>
*/
public String getString()
{
throw new IllegalArgumentException("not an XMLCharData.");
}
/**
* <P>This method returns the character data for this XMLItem with
* leading and trailing whitespace filtered out.</P>
*/
public String getCleanString()
{
throw new IllegalArgumentException("not an XMLCharData.");
}
/**
* <P>This debug method prints out this item and all items
* under this item if this item is the top node in a
* tree.</P>
*/
public void debugPrintTree(int indentLevel)
{
for (int i = 0; i < indentLevel; i++)
{
System.err.print(" ");
}
System.err.println(this.toString());
}
/**
* <P>This debug method appends this item and all items
* under this item if this item is the top node in a
* tree to the StringBuffer passed in.</P>
*/
public void getTreeString(StringBuffer buffer, int indentLevel)
{
for (int i = 0; i < indentLevel; i++)
{
buffer.append(" ");
}
buffer.append(this.toString());
buffer.append("\n");
}
/**
* <P>Convenience method to get a string representation of
* this item and everything under it, if anything.</P>
*/
public String getTreeString()
{
StringBuffer buf = new StringBuffer();
getTreeString(buf, 0);
return buf.toString();
}
}