org.apache.commons.betwixt.io
Class AbstractBeanWriter

java.lang.Object
  |
  +--org.apache.commons.betwixt.io.AbstractBeanWriter

Direct Known Subclasses:

BeanWriter, SAXBeanWriter

public abstract class AbstractBeanWriter

extends java.lang.Object

Abstract superclass for bean writers. This class encapsulates the processing logic. Subclasses provide implementations for the actual expression of the xml.

Version:

$Revision: 1.10 $

Author:

Robert Burrell Donkin

Constructor Summary

AbstractBeanWriter()

Method Summary

void	end() Marks the start of the bean writing.
protected abstract void	expressAttribute(java.lang.String qualifiedName, java.lang.String value) Express an attribute
protected abstract void	expressBodyText(java.lang.String text) Express body text
protected abstract void	expressElementEnd() Express an empty element end.
protected abstract void	expressElementEnd(java.lang.String qualifiedName) Express an element end tag (with given name)
protected abstract void	expressElementStart(java.lang.String qualifiedName) Express an element tag start using given qualified name.
protected abstract void	expressTagClose() Express a closing tag.
org.apache.commons.logging.Log	getAbstractBeanWriterLog() Gets the current logging implementation.
IDGenerator	getIdGenerator() Get IDGenerator implementation used to generate ID attribute values .
protected int	getIndentLevel() Get the indentation for the current element.
boolean	getWriteIDs() Should generated ID attribute values be added to the elements?
XMLIntrospector	getXMLIntrospector() Gets the introspector used.
protected java.lang.Object	popBean() Pops the top bean off from the ancestry stack
protected void	pushBean(java.lang.Object bean) Pushes the bean onto the ancestry stack.
void	setAbstractBeanWriterLog(org.apache.commons.logging.Log log) Set the current logging implementation.
void	setIdGenerator(IDGenerator idGenerator) Set IDGenerator implementation used to generate ID attribute values.
void	setWriteIDs(boolean writeIDs) Set whether generated ID attribute values should be added to the elements If this property is set to false, then CyclicReferenceException will be thrown whenever a cyclic occurs in the bean graph.
void	setXMLIntrospector(XMLIntrospector introspector) Sets the introspector to be used.
void	start() Marks the start of the bean writing.
void	write(java.lang.Object bean) Writes the given bean to the current stream using the XML introspector.
protected void	write(java.lang.String qualifiedName, ElementDescriptor elementDescriptor, Context context) Writes the given element
protected void	write(java.lang.String qualifiedName, ElementDescriptor elementDescriptor, Context context, java.lang.String idAttribute, java.lang.String idValue) Writes the given element adding an ID attribute
void	write(java.lang.String qualifiedName, java.lang.Object bean) Writes the given bean to the current stream using the given qualifiedName.
protected void	writeAttribute(AttributeDescriptor attributeDescriptor, Context context) Writes an attribute declaration
protected void	writeAttributes(ElementDescriptor elementDescriptor, Context context) Writes the attribute declarations
protected boolean	writeContent(ElementDescriptor elementDescriptor, Context context) Writes the element content.
protected void	writeIDREFElement(java.lang.String qualifiedName, java.lang.String idrefAttributeName, java.lang.String idrefAttributeValue) Writes an element with a IDREF attribute
protected void	writeIndent() Writes an indentation.
protected void	writePrintln() Writes a empty line.
protected void	writeRestOfElement(java.lang.String qualifiedName, ElementDescriptor elementDescriptor, Context context) Write attributes, child elements and element end

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractBeanWriter

public AbstractBeanWriter()

Method Detail

start

public void start()
           throws java.io.IOException,
                  org.xml.sax.SAXException

Marks the start of the bean writing. By default doesn't do anything, but can be used to do extra start processing

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

end

public void end()
         throws java.io.IOException,
                org.xml.sax.SAXException

Marks the start of the bean writing. By default doesn't do anything, but can be used to do extra end processing

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

write

public void write(java.lang.Object bean)
           throws java.io.IOException,
                  org.xml.sax.SAXException,
                  java.beans.IntrospectionException

Writes the given bean to the current stream using the XML introspector.

This writes an xml fragment representing the bean to the current stream.

This method will throw a CyclicReferenceException when a cycle is encountered in the graph only if the WriteIDs property is false.

Parameters:

bean - write out representation of this bean

Throws:

CyclicReferenceException - when a cyclic reference is encountered

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

write

public void write(java.lang.String qualifiedName,
                  java.lang.Object bean)
           throws java.io.IOException,
                  org.xml.sax.SAXException,
                  java.beans.IntrospectionException

Writes the given bean to the current stream using the given qualifiedName.

This method will throw a CyclicReferenceException when a cycle is encountered in the graph only if the WriteIDs property is false.

Parameters:

qualifiedName - the string naming root element

bean - the Object to write out as xml

Throws:

CyclicReferenceException - when a cyclic reference is encountered

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

getIdGenerator

public IDGenerator getIdGenerator()

Get IDGenerator implementation used to generate ID attribute values .

Returns:

implementation used for ID attribute generation

getIndentLevel

protected int getIndentLevel()

Get the indentation for the current element. Used for pretty priting.

Returns:

the amount that the current element is indented

setIdGenerator

public void setIdGenerator(IDGenerator idGenerator)

Set IDGenerator implementation used to generate ID attribute values. This property can be used to customize the algorithm used for generation.

Parameters:

idGenerator - use this implementation for ID attribute generation

getWriteIDs

public boolean getWriteIDs()

Should generated ID attribute values be added to the elements?

If IDs are not being written then if a cycle is encountered in the bean graph, then a CyclicReferenceException will be thrown by the write method.

Returns:

true if ID and IDREF attributes are to be written

setWriteIDs

public void setWriteIDs(boolean writeIDs)

Set whether generated ID attribute values should be added to the elements If this property is set to false, then CyclicReferenceException will be thrown whenever a cyclic occurs in the bean graph.

Parameters:

writeIDs - true if ID's and IDREF's should be written

getXMLIntrospector

public XMLIntrospector getXMLIntrospector()

Gets the introspector used.

The XMLBeanInfo used to map each bean is created by the XMLIntrospector. One way in which the mapping can be customized is by altering the XMLIntrospector.

Returns:

the XMLIntrospector used for introspection

setXMLIntrospector

public void setXMLIntrospector(XMLIntrospector introspector)

Sets the introspector to be used.

The XMLBeanInfo used to map each bean is created by the XMLIntrospector. One way in which the mapping can be customized is by altering the XMLIntrospector.

Parameters:

introspector - use this introspector

getAbstractBeanWriterLog

public final org.apache.commons.logging.Log getAbstractBeanWriterLog()

Gets the current logging implementation.

Returns:

the Log implementation which this class logs to

setAbstractBeanWriterLog

public final void setAbstractBeanWriterLog(org.apache.commons.logging.Log log)

Set the current logging implementation.

Parameters:

log - Log implementation to use

expressElementStart

protected abstract void expressElementStart(java.lang.String qualifiedName)
                                     throws java.io.IOException,
                                            org.xml.sax.SAXException

Express an element tag start using given qualified name.

Parameters:

qualifiedName - the qualified name of the element to be expressed

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

expressTagClose

protected abstract void expressTagClose()
                                 throws java.io.IOException,
                                        org.xml.sax.SAXException

Express a closing tag.

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

expressElementEnd

protected abstract void expressElementEnd(java.lang.String qualifiedName)
                                   throws java.io.IOException,
                                          org.xml.sax.SAXException

Express an element end tag (with given name)

Parameters:

qualifiedName - the qualified name for the element to be closed

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

expressElementEnd

protected abstract void expressElementEnd()
                                   throws java.io.IOException,
                                          org.xml.sax.SAXException

Express an empty element end.

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

expressBodyText

protected abstract void expressBodyText(java.lang.String text)
                                 throws java.io.IOException,
                                        org.xml.sax.SAXException

Express body text

Parameters:

text - the string to write out as the body of the current element

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

expressAttribute

protected abstract void expressAttribute(java.lang.String qualifiedName,
                                         java.lang.String value)
                                  throws java.io.IOException,
                                         org.xml.sax.SAXException

Express an attribute

Parameters:

qualifiedName - the qualified name of the attribute

value - the attribute value

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

write

protected void write(java.lang.String qualifiedName,
                     ElementDescriptor elementDescriptor,
                     Context context)
              throws java.io.IOException,
                     org.xml.sax.SAXException,
                     java.beans.IntrospectionException

Writes the given element

Parameters:

qualifiedName - qualified name to use for the element

elementDescriptor - the ElementDescriptor describing the element

context - the Context to use to evaluate the bean expressions

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

write

protected void write(java.lang.String qualifiedName,
                     ElementDescriptor elementDescriptor,
                     Context context,
                     java.lang.String idAttribute,
                     java.lang.String idValue)
              throws java.io.IOException,
                     org.xml.sax.SAXException,
                     java.beans.IntrospectionException

Writes the given element adding an ID attribute

Parameters:

qualifiedName - qualified name to use for the element

elementDescriptor - the ElementDescriptor describing the element

context - the Context to use to evaluate the bean expressions

idAttribute - the qualified name of the ID attribute

idValue - the value for the ID attribute

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

writeRestOfElement

protected void writeRestOfElement(java.lang.String qualifiedName,
                                  ElementDescriptor elementDescriptor,
                                  Context context)
                           throws java.io.IOException,
                                  org.xml.sax.SAXException,
                                  java.beans.IntrospectionException

Write attributes, child elements and element end

Parameters:

qualifiedName - qualified name to use for the element

elementDescriptor - the ElementDescriptor describing the element

context - the Context to use to evaluate the bean expressions

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

writeIDREFElement

protected void writeIDREFElement(java.lang.String qualifiedName,
                                 java.lang.String idrefAttributeName,
                                 java.lang.String idrefAttributeValue)
                          throws java.io.IOException,
                                 org.xml.sax.SAXException,
                                 java.beans.IntrospectionException

Writes an element with a IDREF attribute

Parameters:

qualifiedName - of the element with IDREF attribute

idrefAttributeName - the qualified name of the IDREF attribute

idrefAttributeValue - the value for the IDREF attribute

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

writeContent

protected boolean writeContent(ElementDescriptor elementDescriptor,
                               Context context)
                        throws java.io.IOException,
                               org.xml.sax.SAXException,
                               java.beans.IntrospectionException

Writes the element content.

Parameters:

elementDescriptor - the ElementDescriptor to write as xml

context - the Context to use to evaluate the bean expressions

Returns:

true if some content was written

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

java.beans.IntrospectionException - if a java beans introspection problem occurs

writeAttributes

protected void writeAttributes(ElementDescriptor elementDescriptor,
                               Context context)
                        throws java.io.IOException,
                               org.xml.sax.SAXException

Writes the attribute declarations

Parameters:

elementDescriptor - the ElementDescriptor to be written out as xml

context - the Context to use to evaluation bean expressions

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

writeAttribute

protected void writeAttribute(AttributeDescriptor attributeDescriptor,
                              Context context)
                       throws java.io.IOException,
                              org.xml.sax.SAXException

Writes an attribute declaration

Parameters:

attributeDescriptor - the AttributeDescriptor to be written as xml

context - the Context to use to evaluation bean expressions

Throws:

java.io.IOException - if an IO problem occurs during writing

org.xml.sax.SAXException - if an SAX problem occurs during writing

writePrintln

protected void writePrintln()
                     throws java.io.IOException

Writes a empty line. This implementation does nothing but can be overridden by subclasses.

Throws:

java.io.IOException - if the line cannot be written

writeIndent

protected void writeIndent()
                    throws java.io.IOException

Writes an indentation. This implementation does nothing but can be overridden by subclasses.

Throws:

java.io.IOException - if the indent cannot be written

pushBean

protected void pushBean(java.lang.Object bean)

Pushes the bean onto the ancestry stack. If IDs are not being written, then check for cyclic references.

Parameters:

bean - push this bean onto the ancester stack

Throws:

CyclicReferenceException - if there is an identical bean already on the stack

popBean

protected java.lang.Object popBean()

Pops the top bean off from the ancestry stack

Returns:

the last object pushed onto the ancester stack