org.datanucleus.metadata.xml

Class AbstractMetaDataHandler

java.lang.Object

org.xml.sax.helpers.DefaultHandler

org.datanucleus.metadata.xml.AbstractMetaDataHandler

All Implemented Interfaces:

ContentHandler, DTDHandler, EntityResolver, ErrorHandler

Direct Known Subclasses:

PersistenceFileMetaDataHandler

public class AbstractMetaDataHandler
extends org.xml.sax.helpers.DefaultHandler

Abstract handler for MetaData parsing. Should be extended to handle processing of specific types of metadata.

Field Summary

Fields

Modifier and Type	Field and Description
protected StringBuilder	charactersBuffer parser buffer
protected EntityResolver	entityResolver Entity Resolver to use (if required)
protected String	filename Filename for the parsed file.
protected MetaData	metadata The MetaData for this file (the end result of the parse process.
protected MetaDataManager	mgr Manager for the MetaData.
protected Stack<MetaData>	stack Stack of meta-data elements.
protected boolean	validate Whether to validate while parsing.

Constructor Summary

Constructors

Constructor and Description
AbstractMetaDataHandler(MetaDataManager mgr, String filename, EntityResolver resolver) Constructor.

Method Summary

Modifier and Type	Method and Description
void	characters(char[] ch, int start, int length) Notification handler for the "body" data inside an element.
void	error(SAXParseException e) Parser error method.
protected String	getAttr(Attributes attrs, String key) Accessor for an attribute out of the attributes for an element.
protected String	getAttr(Attributes attrs, String key, String defaultValue) Accessor for an attribute out of the attributes for an element.
MetaData	getMetaData() Accessor for the MetaData for this file.
protected MetaData	getStack() Accessor for the current MetaData component.
String	getString() Accessor for the "body" text metadata.
protected MetaData	popStack() Method to remove the current MetaData component from the Stack.
protected void	pushStack(MetaData md) Method to add a MetaData component to the Stack.
InputSource	resolveEntity(String publicId, String systemId) Method to resolve XML entities.
void	setValidate(boolean validate) Method to set whether to validate during the the handling.

Methods inherited from class org.xml.sax.helpers.DefaultHandler

endDocument, endElement, endPrefixMapping, fatalError, ignorableWhitespace, notationDecl, processingInstruction, setDocumentLocator, skippedEntity, startDocument, startElement, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

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

Field Detail

mgr

protected final MetaDataManager mgr

Manager for the MetaData.

filename

protected final String filename

Filename for the parsed file.

metadata

protected MetaData metadata

The MetaData for this file (the end result of the parse process.

entityResolver

protected final EntityResolver entityResolver

Entity Resolver to use (if required)

charactersBuffer

protected StringBuilder charactersBuffer

parser buffer

validate

protected boolean validate

Whether to validate while parsing.

stack

protected Stack<MetaData> stack

Stack of meta-data elements. The top of the stack is always the element being process at the moment. The elements are not the XML Element type but are things like ClassMetaData, PackageMetaData etc.

Constructor Detail

AbstractMetaDataHandler

public AbstractMetaDataHandler(MetaDataManager mgr,
                               String filename,
                               EntityResolver resolver)

Constructor.

Parameters:

mgr - Manager for the MetaData

filename - The filename

resolver - Entity Resolver to use (null if not available)

Method Detail

setValidate

public void setValidate(boolean validate)

Method to set whether to validate during the the handling.

Parameters:

validate - Whether to validate

getMetaData

public MetaData getMetaData()

Accessor for the MetaData for this file.

Returns:

The MetaData.

error

public void error(SAXParseException e)
           throws SAXException

Parser error method. If any syntactical errors are encountered on validation they will appear here and be logged as warnings. Just points the user to the line/column of their Meta-Data file for now.

Specified by:

error in interface ErrorHandler

Overrides:

error in class org.xml.sax.helpers.DefaultHandler

Parameters:

e - Parse Exception

Throws:

SAXException

See Also:

ErrorHandler.error(org.xml.sax.SAXParseException)

getAttr

protected String getAttr(Attributes attrs,
                         String key,
                         String defaultValue)

Accessor for an attribute out of the attributes for an element. Allows the specification of a default if no value is provided.

Parameters:

attrs - The attributes

key - Key for the attribute to return

defaultValue - A default to impose if no value.

Returns:

Value for the attribute with the specified key.

getAttr

protected String getAttr(Attributes attrs,
                         String key)

Accessor for an attribute out of the attributes for an element.

Parameters:

attrs - The attributes

key - Key for the attribute to return

Returns:

Value for the attribute with the specified key.

resolveEntity

public InputSource resolveEntity(String publicId,
                                 String systemId)
                          throws SAXException

Method to resolve XML entities. Uses the entity resolver (if provided) to check for local variants.

Specified by:

resolveEntity in interface EntityResolver

Overrides:

resolveEntity in class org.xml.sax.helpers.DefaultHandler

Parameters:

publicId - The public id.

systemId - The system id.

Returns:

Input Source for the URI.

Throws:

SAXException

See Also:

EntityResolver.resolveEntity(java.lang.String,java.lang.String)

characters

public void characters(char[] ch,
                       int start,
                       int length)
                throws SAXException

Notification handler for the "body" data inside an element.

Specified by:

characters in interface ContentHandler

Overrides:

characters in class org.xml.sax.helpers.DefaultHandler

Parameters:

ch - The characters

start - The start position in the character array.

length - The length of the string.

Throws:

SAXException - in parsing errors

getString

public String getString()

Accessor for the "body" text metadata. Resets the body text after access.

Returns:

the string form of this metadata

getStack

protected MetaData getStack()

Accessor for the current MetaData component.

Returns:

The current MetaData component.

popStack

protected MetaData popStack()

Method to remove the current MetaData component from the Stack.

Returns:

Latest MetaData component.

pushStack

protected void pushStack(MetaData md)

Method to add a MetaData component to the Stack.

Parameters:

md - The component to add.