diva.util.xml
Class XmlElement

java.lang.Object
  diva.util.xml.XmlElement

public class XmlElement
extends java.lang.Object

An XmlElement is a node of a tree representing an XML file. It is a concrete class. An XmlReader object will construct a tree of XmlElements from an XML file and place it into an XmlDocument. Applications can traverse a tree of XmlElements to extract data or build their own application-specific data structure. They can also construct a tree of XmlElements and add it to an XmlDocument and generate an XML output file.

Version:

$Id: XmlElement.java 38798 2005-07-08 20:00:01Z cxh $

Author:

Steve Neuendorffer, John Reekie

Field Summary

private java.util.TreeMap	_attributes
private java.util.List	_children The child elements of this element.
private XmlElement	_parent
private java.lang.String	_pcdata
private java.lang.String	_type

Constructor Summary

XmlElement()
Create a new XmlElement of unknown type.

XmlElement(java.lang.String type)
Create a new XmlElement with element type given by the string.

XmlElement(java.lang.String type, java.util.Map attrs)
Create a new XmlElement with element type with the given name and the given attributes.

Method Summary

void	addElement(XmlElement e) Add a child element to this element.
void	appendPCData(java.lang.String s) Add the String to the end of the current PCDATA for this element.
java.util.Iterator	attributeNames() Return an enumeration over the names of the attributes in this schematic.
boolean	containsElement(XmlElement elt) Test if this element contains the given element.
int	elementCount() Return the number of child elements.
java.util.Iterator	elements() Return an Iterator of all the child elements of this element.
java.util.Iterator	elements(java.lang.String type) Return an Iterator of all the child elements of this element that have the given element type.
java.lang.String	getAttribute(java.lang.String name) Return the value of the attribute with the given name, or null if there isn't one.
java.util.Map	getAttributeMap() Return the map from attribute names to value.
java.util.List	getChildList() Return the list of child elements.
XmlElement	getElement(java.lang.String type) Return the first child element of this element with the given type, or null if there isn't one.
XmlElement	getElement(java.lang.String type, java.lang.String name) Return the first child element of this element with the given type and name, or null if there isn't one.
XmlElement	getParent() Return the parent element of this element, or null if it has no parent.
java.lang.String	getPCData() Return the PCData that is associated with this XmlElement.
java.lang.String	getType() Return the type of this XmlElement.
boolean	hasAttribute(java.lang.String name) Test if this element has the attribute with the given name.
void	removeAttribute(java.lang.String name) Remove an attribute from this element
void	removeElement(XmlElement e) Remove a child element from this element
void	setAttribute(java.lang.String name, java.lang.String value) Set the attribute with the given name to the given value.
void	setParent(XmlElement p) Set the parent element of this element.
void	setPCData(java.lang.String s) Set the text of this element to the given string.
void	setType(java.lang.String s) Set the type of this element
java.lang.String	toString() Convert this element to a string in XML
void	writeXML(java.io.Writer out, java.lang.String prefix) Print this element to a Writer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_children

private java.util.List _children

The child elements of this element. Could be a LinkedList instead, I suppose...

_attributes

private java.util.TreeMap _attributes

_type

private java.lang.String _type

_pcdata

private java.lang.String _pcdata

_parent

private XmlElement _parent

Constructor Detail

XmlElement

public XmlElement(java.lang.String type)

Create a new XmlElement with element type given by the string. The element has no attributes and no child elements.

Parameters:

type - The element type

XmlElement

public XmlElement()

Create a new XmlElement of unknown type.

XmlElement

public XmlElement(java.lang.String type,
                  java.util.Map attrs)

Create a new XmlElement with element type with the given name and the given attributes. The element starts with no child elements.

Parameters:

type - The element type

attrs - The attributes of this XmlElement.

Method Detail

addElement

public void addElement(XmlElement e)

Add a child element to this element. Child elements are ordered.

appendPCData

public void appendPCData(java.lang.String s)

Add the String to the end of the current PCDATA for this element.

attributeNames

public java.util.Iterator attributeNames()

Return an enumeration over the names of the attributes in this schematic. There is no order guarantee on the attributes.

containsElement

public boolean containsElement(XmlElement elt)

Test if this element contains the given element. This is included mainly to allow test suites to be written. In general, check the parent of the child.

elementCount

public int elementCount()

Return the number of child elements.

elements

public java.util.Iterator elements()

Return an Iterator of all the child elements of this element. The elements are generated in the order in which they were added.

elements

public java.util.Iterator elements(java.lang.String type)

Return an Iterator of all the child elements of this element that have the given element type.

Returns:

an Iterator of XmlElements

getAttribute

public java.lang.String getAttribute(java.lang.String name)

Return the value of the attribute with the given name, or null if there isn't one.

getAttributeMap

public java.util.Map getAttributeMap()

Return the map from attribute names to value. This returns the internal object that holds attributes, and is provided so that more sophisticated operations than provided by the methods in this interface can be implemented when needed. Note: if you add any attributes to this list, you must be sure that the value is a String.

getChildList

public java.util.List getChildList()

Return the list of child elements. This returns the internal object that holds child elements, and is provided so that more sophisticated operations than provided by the methods in this interface can be implemented when needed. Note: if you add any elements to this list, you MUST call the setParent() method of that element with this object.

getElement

public XmlElement getElement(java.lang.String type)

Return the first child element of this element with the given type, or null if there isn't one.

getElement

public XmlElement getElement(java.lang.String type,
                             java.lang.String name)

Return the first child element of this element with the given type and name, or null if there isn't one.

getType

public java.lang.String getType()

Return the type of this XmlElement. The type is immutably set when the XmlElement is created.

getParent

public XmlElement getParent()

Return the parent element of this element, or null if it has no parent.

getPCData

public java.lang.String getPCData()

Return the PCData that is associated with this XmlElement.

hasAttribute

public boolean hasAttribute(java.lang.String name)

Test if this element has the attribute with the given name.

removeAttribute

public void removeAttribute(java.lang.String name)

Remove an attribute from this element

removeElement

public void removeElement(XmlElement e)

Remove a child element from this element

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.String value)

Set the attribute with the given name to the given value. Throw an exception if there is no attribute with the given name in this schematic.

setParent

public void setParent(XmlElement p)

Set the parent element of this element.

setPCData

public void setPCData(java.lang.String s)

Set the text of this element to the given string.

setType

public void setType(java.lang.String s)

Set the type of this element

toString

public java.lang.String toString()

Convert this element to a string in XML

Overrides:

toString in class java.lang.Object

writeXML

public void writeXML(java.io.Writer out,
                     java.lang.String prefix)
              throws java.io.IOException

Print this element to a Writer

Throws:

java.io.IOException