com.topologi.diffx.xml
Interface XMLWriter

All Known Subinterfaces:

DOMWriter

All Known Implementing Classes:

DOMWriterImpl, XMLStringWriter, XMLWriterImpl, XMLWriterNSImpl, XMLWriterSAX

public interface XMLWriter

Defines a writer for XML data.

This interface provides simple methods to write XML data onto a writer.

Most implementation should wrap a writer or an output stream. Implementations can be focused on performance, reliability, error reporting, etc...

For improved performance, the most efficient solution will generally to have an implementation write on a buffered writer since the memory usage will generally be restricted little more than the size of the buffer, and this will keep the I/O operation to a minimum.

Other implementations might want to wrap a SAX content handler.

Version:

11 December 2011

Author:

Christophe Lauret (Allette Systems)

Method Summary

void	attribute(String name, int value) Writes an attribute.
void	attribute(String name, String value) Writes an attribute.
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() Close the element automatically.
void	element(String name, String text) Opens element, inserts text node and closes.
void	emptyElement(String element) Writes an empty element.
void	emptyElement(String uri, String element) Writes an empty element.
void	flush() Flush the writer.
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, boolean hasChildren) Writes a start element tag correctly indented.
void	setIndentChars(String spaces) Sets the string to use for indentation.
void	setPrefixMapping(String uri, String prefix) Sets a prefix mapping.
void	writeCDATA(String data) Writes the given text as a CDATA section.
void	writeComment(String comment) Writes an XML comment.
void	writePI(String target, String data) Writes an XML processing instruction.
void	writeText(char c) Writes the given character correctly for the encoding of this document.
void	writeText(char[] text, int off, int len) Write the given text correctly for the encoding of this document.
void	writeText(String text) Writes the given text correctly for the encoding of this document.
void	writeXML(char[] text, int off, int len) Write the given XML data.
void	writeXML(String text) Writes the given XML data.
void	xmlDecl() Writes the XML declaration.

Method Detail

xmlDecl

void xmlDecl()
             throws IOException

Writes the XML declaration.

Always:

   <?xml version="1.0" encoding="encoding"?>
 

It is followed by a new line character if the indentation is turned on.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

IllegalStateException - If this method is called after the writer has started writing elements nodes.

setIndentChars

void setIndentChars(String spaces)

Sets the string to use for indentation.

The string must be only composed of valid spaces characters.

If the string is null then the indentation is turned off.

Parameters:

spaces - The indentation string to use.

Throws:

IllegalArgumentException - If the indent string is not made of spaces.

IllegalStateException - If the writer has already been used.

See Also:

Character.isSpaceChar(char)

writeText

void writeText(char c)
               throws IOException

Writes the given character correctly for the encoding of this document.

Parameters:

c - The character to write.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

writeText

void writeText(String text)
               throws IOException

Writes the given text correctly for the encoding of this document.

Does nothing if the text is null.

Parameters:

text - The text to write

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

writeText

void writeText(char[] text,
               int off,
               int len)
               throws IOException

Write the given text correctly for the encoding of this document.

Parameters:

text - The text to write.

off - The offset where we should start writing the string.

len - The length of the character subarray to write.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

writeCDATA

void writeCDATA(String data)
                throws IOException

Writes the given text as a CDATA section.

Does nothing if the text is null.

Parameters:

data - The data to write inside the CDATA section.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

IllegalArgumentException - If the implementation does not support CDATA nesting

writeXML

void writeXML(String text)
              throws IOException

Writes the given XML data.

The text is appended as is, therefore it should be escaped properly for the encoding used by the underlying stream writer.

Does nothing if the text is null.

Parameters:

text - The text to write.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

writeXML

void writeXML(char[] text,
              int off,
              int len)
              throws IOException

Write the given XML data.

The text is appended as is, therefore it should be escaped properly for the encoding used by the underlying stream writer.

Parameters:

text - The text to write.

off - The offset where we should start writing the string.

len - The length of the character subarray to write.

Throws:

IOException - If an I/O exception is thrown by the underlying writer.

writeComment

void writeComment(String comment)
                  throws IOException

Writes an XML comment.

An XML comment is:

   <!-- comment -->
 

Comments are not indented.

Does not write anything if the comment if null.

Parameters:

comment - The comment to be written

Throws:

IOException - If thrown by the wrapped writer.

IllegalArgumentException - If the comment contains "--".

writePI

void writePI(String target,
             String data)
             throws IOException

Writes an XML processing instruction.

An XML processing intruction is:

   <?target data?>
 

Parameters:

target - The PI's target.

data - The PI's data.

Throws:

IOException - If an I/O exception occurs.

openElement

void openElement(String name)
                 throws IOException

Writes a start element tag correctly indented.

It is the same as openElement(name, false)

Parameters:

name - the name of the element

Throws:

IOException - If an I/O exception occurs.

See Also:

openElement(java.lang.String, boolean)

openElement

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.

Parameters:

name - The name of the element

hasChildren - true if this element has children

Throws:

IOException - If an I/O exception occurs.

openElement

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.

Parameters:

uri - The namespace URI of the element.

name - The name of the element.

hasChildren - true if this element has children.

Throws:

IOException - If an I/O exception occurs.

UnsupportedOperationException - If the implementing class does not handle namespace.

closeElement

void closeElement()
                  throws IOException

Close the element automatically.

The element is closed symmetrically to the openElement(String, String, boolean) method if the XML writer is namespace aware or the openElement(String, boolean)method.

Throws:

IOException - If an I/O exception occurs.

element

void element(String name,
             String text)
             throws IOException

Opens element, inserts text node and closes.

This method should behave like:

   this.openElement(name, false);
   this.writeText(text);
   this.closeElement();
 

Parameters:

name - The name of the element.

text - The text of the element.

Throws:

IOException - If thrown by the wrapped writer.

emptyElement

void emptyElement(String element)
                  throws IOException

Writes 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"/>
 

Parameters:

element - the name of the element

Throws:

IOException - If an I/O exception occurs.

UnsupportedOperationException - If the implementing class does not handle namespace.

emptyElement

void emptyElement(String uri,
                  String element)
                  throws IOException

Writes 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"/>
 

Parameters:

uri - The namespace URI of the element.

element - The name of the element.

Throws:

IOException - If an I/O exception occurs.

UnsupportedOperationException - If the implementing class does not handle namespace.

attribute

void attribute(String name,
               String value)
               throws IOException

Writes an attribute.

Parameters:

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

void attribute(String name,
               int value)
               throws IOException

Writes an attribute.

This method for number does not require escaping.

Parameters:

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

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

Writes an attribute.

Parameters:

uri - The uri of the attribute.

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.

UnsupportedOperationException - If the implementing class does not handle namespace.

attribute

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

Writes an attribute.

This method for number does not require escaping.

Parameters:

uri - The uri of the attribute.

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.

UnsupportedOperationException - If the implementing class does not handle namespace.

setPrefixMapping

void setPrefixMapping(String uri,
                      String prefix)

Sets a prefix mapping.

Parameters:

uri - The namespace URI.

prefix - The new prefix for the namespace URI.

Throws:

UnsupportedOperationException - If the implementing class does not handle namespace.

flush

void flush()
           throws IOException

Flush the writer.

Throws:

IOException - If thrown by the wrapped writer.

close

void close()
           throws IOException

Close the writer.

Throws:

IOException - If thrown by the wrapped writer.

UnclosedElementException - If there is still an open element.