Package com.topologi.diffx.xml

Class XMLWriterNSImpl

java.lang.Object

com.topologi.diffx.xml.XMLWriterBase

com.topologi.diffx.xml.XMLWriterNSImpl

All Implemented Interfaces:

XMLWriter

public final class XMLWriterNSImpl
extends XMLWriterBase
implements XMLWriter

A Namespace-aware writer for XML data.

Provides methods to generate well-formed XML data easily. wrapping a writer.

This version only supports utf-8 encoding, if writing to a file make sure that the encoding of the file output stream is "utf-8".

The recommended implementation is to use a BufferedWriter to write.

  Writer writer =
     new BufferedWriter(new OutputStreamWriter(new FileOutputStream("foo.out"),"utf-8"));
 

This class is not synchronised.

Version:

11 December 2011

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	XMLWriterNSImpl.Element	A light object to keep track of the elements
private static final class	XMLWriterNSImpl.PrefixMapping	Light-weight class to represent a prefix mapping.

Field Summary

Fields

Modifier and Type	Field	Description
private static final boolean	DEBUG	Set to true to show debug info.
private static final XMLWriterNSImpl.PrefixMapping	DEFAULT_NS	The default namespace mapped to the empty prefix.
private final List<XMLWriterNSImpl.Element>	elements	A stack of elements to close the elements automatically.
private final Map<String,String>	prefixMapping	The current prefix mapping.
private static final XMLWriterNSImpl.Element	ROOT	The root node.
private List<XMLWriterNSImpl.PrefixMapping>	tempMapping	The list of prefix mappings to be associated with the next element.

Fields inherited from class com.topologi.diffx.xml.XMLWriterBase

depth, encoding, indent, isNude, writer, writerEscape

Constructor Summary

Constructors

Constructor	Description
XMLWriterNSImpl(Writer writer)	Creates a new XML writer.
XMLWriterNSImpl(Writer writer, boolean indent)	Create a new XML writer.

Method Summary

Modifier and Type	Method	Description
void	attribute(String uri, String name, int value)	Writes an attribute.
void	attribute(String uri, String name, String value)	Writes an attribute.
void	close()	Close the writer.
void	closeElement()	Write an end element tag.
(package private) void	deNude()	Writes the angle bracket if the element open tag is not finished.
void	emptyElement(String element)	Same as emptyElement(null, element);.
void	emptyElement(String uri, String element)	Write an empty element.
private String	getQName(String uri, String name)	Returns the qualified name for this element using the specified namespace URI.
private void	handleNamespaceDeclaration()	Handles the namespace declaration and updates the prefix mappings.
void	openElement(String name)	Writes a start element tag correctly indented.
void	openElement(String name, boolean hasChildren)	Writes a start element tag correctly indented.
void	openElement(String uri, String name)	Write a start element tag correctly indented.
void	openElement(String uri, String name, boolean hasChildren)	Writes a start element tag correctly indented.
private XMLWriterNSImpl.Element	peekElement()	Returns the last element in the list.
private XMLWriterNSImpl.Element	popElement()	Removes the last element in the list.
private void	removeIfNeeded(String prefix)	Removes the mapping associated to the specified prefix.
private void	restorePrefixMapping(XMLWriterNSImpl.Element elt)	Restores the prefix mapping after closing an element.
void	setPrefixMapping(String uri, String prefix)	Sets a prefix mapping.

Methods inherited from class com.topologi.diffx.xml.XMLWriterBase

attribute, attribute, doNothing, element, flush, indent, setEncoding, setIndentChars, writeCDATA, writeComment, writePI, writeText, writeText, writeText, writeText, writeXML, writeXML, xmlDecl

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.topologi.diffx.xml.XMLWriter

attribute, attribute, element, flush, setIndentChars, writeCDATA, writeComment, writePI, writeText, writeText, writeText, writeXML, writeXML, xmlDecl

Field Details

DEBUG

private static final boolean DEBUG

Set to true to show debug info.

See Also:

• Constant Field Values

DEFAULT_NS

private static final XMLWriterNSImpl.PrefixMapping DEFAULT_NS

The default namespace mapped to the empty prefix.

ROOT

private static final XMLWriterNSImpl.Element ROOT

The root node.

prefixMapping

private final Map<String,String> prefixMapping

The current prefix mapping.

tempMapping

private List<XMLWriterNSImpl.PrefixMapping> tempMapping

The list of prefix mappings to be associated with the next element.

elements

private final List<XMLWriterNSImpl.Element> elements

A stack of elements to close the elements automatically.

Constructor Details

XMLWriterNSImpl

public XMLWriterNSImpl(Writer writer)
                throws NullPointerException

Creates a new XML writer.

Sets the depth attribute to 0 and the indentation to true.

Parameters:

writer - Where this writer should write the XML data.

Throws:

NullPointerException - If the writer is null.

XMLWriterNSImpl

public XMLWriterNSImpl(Writer writer,
 boolean indent)
                throws NullPointerException

Create a new XML writer.

Parameters:

writer - Where this writer should write the XML data.

indent - Set the indentation flag.

Throws:

NullPointerException - If the writer is null.

Method Details

deNude

void deNude()
     throws IOException

Writes the angle bracket if the element open tag is not finished.

Specified by:

deNude in class XMLWriterBase

Throws:

IOException - If thrown by the wrapped writer.

openElement

public void openElement(String name)
                 throws IOException

Writes a start element tag correctly indented.

It is the same as openElement(null, name, false)

Specified by:

openElement in interface XMLWriter

Parameters:

name - the name of the element

Throws:

IOException - If thrown by the wrapped writer.

See Also:

• openElement(java.lang.String, java.lang.String, boolean)

openElement

public void openElement(String uri,
 String name)
                 throws IOException

Write a start element tag correctly indented.

It is the same as openElement(name, false)

Parameters:

uri - The namespace URI of this element.

name - The name of the element.

Throws:

IOException - If thrown by the wrapped writer.

See Also:

• openElement(java.lang.String, boolean)

openElement

public void openElement(String name,
 boolean hasChildren)
                 throws IOException

Writes a start element tag correctly indented.

Use the hasChildren parameter to specify whether this element is terminal node or not, note: this affects the indenting. To produce correctly indented XML, you should use the same value for this flag when closing the element.

The name can contain attributes and should be a valid xml name.

Specified by:

openElement in interface XMLWriter

Parameters:

name - The name of the element.

hasChildren - true if this element has children.

Throws:

IOException - If thrown by the wrapped writer.

openElement

public void openElement(String uri,
 String name,
 boolean hasChildren)
                 throws IOException

Writes a start element tag correctly indented.

Use the hasChildren parameter to specify whether this element is terminal node or not, note: this affects the indenting. To produce correctly indented XML, you should use the same value for this flag when closing the element.

The name can contain attributes and should be a valid xml name.

Specified by:

openElement in interface XMLWriter

Parameters:

uri - The namespace URI of this element.

name - The name of the element.

hasChildren - true if this element has children.

Throws:

IOException - If thrown by the wrapped writer.

closeElement

public void closeElement()
                  throws IOException

Write an end element tag.

Specified by:

closeElement in interface XMLWriter

Throws:

IOException - If thrown by the wrapped writer.

emptyElement

public void emptyElement(String element)
                  throws IOException

Same as emptyElement(null, element);.

Specified by:

emptyElement in interface XMLWriter

Parameters:

element - the name of the element

Throws:

IOException - If thrown by the wrapped writer.

emptyElement

public void emptyElement(String uri,
 String element)
                  throws IOException

Write an empty element.

It is possible for the element to contain attributes, however, since there is no character escaping, great care must be taken not to introduce invalid characters. For example:

    <example test="yes"/>
 

Specified by:

emptyElement in interface XMLWriter

Parameters:

uri - The namespace URI for this element.

element - The name of the element.

Throws:

IOException - If thrown by the wrapped writer.

peekElement

private XMLWriterNSImpl.Element peekElement()

Returns the last element in the list.

Returns:

The current element.

popElement

private XMLWriterNSImpl.Element popElement()

Removes the last element in the list.

Returns:

The current element.

attribute

public void attribute(String uri,
 String name,
 String value)
               throws IOException,
IllegalStateException

Writes an attribute.

Specified by:

attribute in interface XMLWriter

Parameters:

uri - The namespcae URI this attribute belongs to.

name - The name of the attribute.

value - The value of the attribute.

Throws:

IOException - If thrown by the wrapped writer.

IllegalStateException - If there is no open element or text has been written.

attribute

public void attribute(String uri,
 String name,
 int value)
               throws IOException,
IllegalStateException

Writes an attribute.

This method for number does not require escaping.

Specified by:

attribute in interface XMLWriter

Parameters:

uri - The namespcae URI this attribute belongs to.

name - The name of the attribute.

value - The value of the attribute.

Throws:

IOException - If thrown by the wrapped writer.

IllegalStateException - If there is no open element or text has been written.

setPrefixMapping

public void setPrefixMapping(String uri,
 String prefix)
                      throws NullPointerException

Description copied from interface: XMLWriter

Sets a prefix mapping.

Specified by:

setPrefixMapping in interface XMLWriter

Parameters:

uri - The full namespace URI.

prefix - The prefix for the namespace uri.

Throws:

NullPointerException - if the prefix is null.

See Also:

• This implementation does not keep a history of the prefix mappings so it needs to be reset. If a prefix is already being used it is overridden.

getQName

private String getQName(String uri,
 String name)
                 throws UndeclaredNamespaceException

Returns the qualified name for this element using the specified namespace URI.

Parameters:

uri - The namespace URI for the element.

name - The name of the element or attribute.

Returns:

The qualified element name.

Throws:

UndeclaredNamespaceException - If the uri has not being previously declared.

handleNamespaceDeclaration

private void handleNamespaceDeclaration()
                                 throws IOException

Handles the namespace declaration and updates the prefix mappings.

Throws:

IOException - If thrown by the wrapped writer.

restorePrefixMapping

private void restorePrefixMapping(XMLWriterNSImpl.Element elt)

Restores the prefix mapping after closing an element.

This costly operation need only to be done if the method setPrefixMapping(String, String) have been used immediately before, therefore it should not happen often.

Parameters:

elt - The element that had some new mappings.

removeIfNeeded

private void removeIfNeeded(String prefix)

Removes the mapping associated to the specified prefix.

Parameters:

prefix - The prefix which mapping should be removed.

close

public void close()
           throws IOException,
UnclosedElementException

Close the writer.

Specified by:

close in interface XMLWriter

Throws:

IOException - If thrown by the wrapped writer.

UnclosedElementException - If an element has been left open.