org.opencastproject.mediapackage

Class XMLCatalogImpl

java.lang.Object

org.opencastproject.mediapackage.AbstractMediaPackageElement

org.opencastproject.mediapackage.CatalogImpl

org.opencastproject.mediapackage.XMLCatalogImpl

All Implemented Interfaces:

Serializable, Cloneable, Comparable<MediaPackageElement>, Catalog, ManifestContributor, MediaPackageElement, XMLCatalog

public abstract class XMLCatalogImpl
extends CatalogImpl
implements XMLCatalog

This is a basic implementation for handling simple catalogs of metadata. It provides utility methods to store key-value data.

For a definition of the terms expanded name, qualified name or QName, namespace prefix, local part and local name, please see http://www.w3.org/TR/REC-xml-names

By default the following namespace prefixes are bound:

• xml - http://www.w3.org/XML/1998/namespace
• xmlns - http://www.w3.org/2000/xmlns/
• xsi - http://www.w3.org/2001/XMLSchema-instance

Limitations

XMLCatalog supports only one prefix binding per namespace name, so you cannot create documents like the following using XMLCatalog:

 <root xmlns:x="http://x.demo.org" xmlns:y="http://x.demo.org">
   <x:elem>value</x:elem>
   <y:elem>value</y:elem>
 </root>
 

However, reading of those documents is supported.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	XMLCatalogImpl.CatalogEntry Element representation.

Nested classes/interfaces inherited from class org.opencastproject.mediapackage.CatalogImpl

CatalogImpl.Adapter

Nested classes/interfaces inherited from interface org.opencastproject.mediapackage.MediaPackageElement

MediaPackageElement.Type

Field Summary

Fields

Modifier and Type	Field and Description
protected XmlNamespaceContext	bindings Namespace - prefix bindings
protected Map<EName,List<XMLCatalogImpl.CatalogEntry>>	data Key (QName) value meta data
protected boolean	includeEmpty To marshaling empty fields to remove existing values during merge, default is not to marshal empty elements
static EName	XML_LANG_ATTR Expanded name of the XML language attribute xml:lang.
static String	XSI_NS_PREFIX Namespace prefix for XML schema instance.
static EName	XSI_TYPE_ATTR Expanded name of the XSI type attribute.

Fields inherited from class org.opencastproject.mediapackage.AbstractMediaPackageElement

checksum, description, elementType, flavor, id, mediaPackage, mimeType, reference, size, tags, uri

Fields inherited from interface org.opencastproject.mediapackage.Catalog

TYPE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	XMLCatalogImpl() Create an empty catalog and register the XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI namespace.

Method Summary

Modifier and Type	Method and Description
protected void	addBinding(XmlNamespaceBinding binding)
protected void	addElement(EName element, String value) Adds the element to the metadata collection.
protected void	addElement(EName element, String value, Attributes attributes) Adds an element with attributes to the catalog.
protected void	addLocalizedElement(EName element, String value, String language) Adds the element with the xml:lang attribute to the metadata collection.
protected void	addTypedElement(EName element, String value, EName type) Adds the element with the xsi:type attribute to the metadata collection.
protected void	addTypedLocalizedElement(EName element, String value, String language, EName type) Adds an element with the xml:lang and xsi:type attributes to the metadata collection.
protected void	clear() Clears the catalog.
protected boolean	equal(Object a, Object b) Tests two objects for equality.
protected XmlNamespaceContext	getBindings()
protected List<XMLCatalogImpl.CatalogEntry>	getEntriesSorted()
protected XMLCatalogImpl.CatalogEntry	getFirstLocalizedValue(EName element, String language) Returns the first value that is associated with the specified name and language.
protected XMLCatalogImpl.CatalogEntry	getFirstTypedValue(EName element, String type) Returns the first value that is associated with the specified name and language.
protected XMLCatalogImpl.CatalogEntry	getFirstValue(EName element) Returns the first value that is associated with the specified name.
protected XMLCatalogImpl.CatalogEntry	getFirstValue(EName element, EName attributeEName, String attributeValue) Returns the first element that is associated with the specified name and attribute.
protected List<XMLCatalogImpl.CatalogEntry>	getLocalizedValuesAsList(EName element, String language) Returns the values that are associated with the specified key.
protected String	getPrefix(String namespaceURI) Get a prefix from bindings but throw a NamespaceBindingException if none found.
protected XMLCatalogImpl.CatalogEntry[]	getValues(EName element) Returns the values that are associated with the specified key.
protected List<XMLCatalogImpl.CatalogEntry>	getValuesAsList(EName element) Returns the values that are associated with the specified key.
void	includeEmpty(boolean includeEmpty) Marshal elements with empty values to support remove existing values during catalog merge.
protected Document	newDocument() Creates an xml document root and returns it.
protected void	removeElement(EName element) Completely removes an element.
protected void	removeLocalizedValues(EName element, String language) Removes all entries in a certain language from an element.
protected void	saveToXml(Node document, String docType, OutputStream out) Serializes the given xml document to the associated file.
protected EName	toEName(String qName) Transform a qualified name to an expanded name, based on the registered binding.
protected EName	toEName(String prefix, String localName) Transform an qualified name consisting of prefix and local part to an expanded name, based on the registered binding.
Node	toManifest(Document document, MediaPackageSerializer serializer) This method returns an XML serialization of the object to be stored in the media package manifest.
protected String	toQName(EName eName) Transform an expanded name to a qualified name based on the registered binding.
void	toXml(OutputStream out, boolean format) Writes an xml representation of this Catalog to a stream.
String	toXmlString() Writes an xml representation of this Catalog to a string.

Methods inherited from class org.opencastproject.mediapackage.CatalogImpl

fromFile, fromURI, newInstance

Methods inherited from class org.opencastproject.mediapackage.AbstractMediaPackageElement

addTag, clearReference, clearTags, clone, compareTo, containsTag, containsTag, equals, getChecksum, getElementDescription, getElementType, getFlavor, getIdentifier, getMediaPackage, getMimeType, getReference, getSize, getTags, getURI, hashCode, referTo, referTo, referTo, removeTag, setChecksum, setElementDescription, setFlavor, setIdentifier, setMimeType, setReference, setSize, setURI, toString, verify

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.opencastproject.mediapackage.XMLCatalog

toJson, toXml

Methods inherited from interface org.opencastproject.mediapackage.MediaPackageElement

addTag, clearReference, clearTags, clone, containsTag, containsTag, getChecksum, getElementDescription, getElementType, getFlavor, getIdentifier, getMediaPackage, getMimeType, getReference, getSize, getTags, getURI, referTo, referTo, referTo, removeTag, setChecksum, setElementDescription, setFlavor, setIdentifier, setMimeType, setReference, setSize, setURI, verify

Methods inherited from interface java.lang.Comparable

compareTo

Field Detail

XML_LANG_ATTR

public static final EName XML_LANG_ATTR

Expanded name of the XML language attribute xml:lang.

XSI_NS_PREFIX

public static final String XSI_NS_PREFIX

Namespace prefix for XML schema instance.

See Also:

Constant Field Values

includeEmpty

protected boolean includeEmpty

To marshaling empty fields to remove existing values during merge, default is not to marshal empty elements

XSI_TYPE_ATTR

public static final EName XSI_TYPE_ATTR

Expanded name of the XSI type attribute.

See http://www.w3.org/TR/xmlschema-1/#xsi_type for the definition.

data

protected final Map<EName,List<XMLCatalogImpl.CatalogEntry>> data

Key (QName) value meta data

bindings

protected XmlNamespaceContext bindings

Namespace - prefix bindings

Constructor Detail

XMLCatalogImpl

protected XMLCatalogImpl()

Create an empty catalog and register the XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI namespace.

Method Detail

addBinding

protected void addBinding(XmlNamespaceBinding binding)

getBindings

protected XmlNamespaceContext getBindings()

clear

protected void clear()

Clears the catalog.

addElement

protected void addElement(EName element,
                          String value)

Adds the element to the metadata collection.

Parameters:

element - the expanded name of the element

value - the value

addLocalizedElement

protected void addLocalizedElement(EName element,
                                   String value,
                                   String language)

Adds the element with the xml:lang attribute to the metadata collection.

Parameters:

element - the expanded name of the element

value - the value

language - the language identifier (two letter ISO 639)

addTypedElement

protected void addTypedElement(EName element,
                               String value,
                               EName type)

Adds the element with the xsi:type attribute to the metadata collection.

Parameters:

value - the value

type - the element type

addTypedLocalizedElement

protected void addTypedLocalizedElement(EName element,
                                        String value,
                                        String language,
                                        EName type)

Adds an element with the xml:lang and xsi:type attributes to the metadata collection.

Parameters:

element - the expanded name of the element

value - the value

language - the language identifier (two letter ISO 639)

type - the element type

addElement

protected void addElement(EName element,
                          String value,
                          Attributes attributes)

Adds an element with attributes to the catalog.

Parameters:

element - the expanded name of the element

value - the element's value

attributes - the attributes. May be null

removeElement

protected void removeElement(EName element)

Completely removes an element.

Parameters:

element - the expanded name of the element

removeLocalizedValues

protected void removeLocalizedValues(EName element,
                                     String language)

Removes all entries in a certain language from an element.

Parameters:

element - the expanded name of the element

language - the language code (two letter ISO 639) or null to only remove entries without an xml:lang attribute

getValues

protected XMLCatalogImpl.CatalogEntry[] getValues(EName element)

Returns the values that are associated with the specified key.

Parameters:

element - the expanded name of the element

Returns:

the elements

getEntriesSorted

protected List<XMLCatalogImpl.CatalogEntry> getEntriesSorted()

getValuesAsList

protected List<XMLCatalogImpl.CatalogEntry> getValuesAsList(EName element)

Returns the values that are associated with the specified key.

Parameters:

element - the expanded name of the element

Returns:

all values of the element or an empty list if this element does not exist or does not have any values

getLocalizedValuesAsList

protected List<XMLCatalogImpl.CatalogEntry> getLocalizedValuesAsList(EName element,
                                                                     String language)

Returns the values that are associated with the specified key.

Parameters:

element - the expandend name of the element

language - a language code or null to get values without xml:lang attribute

Returns:

all values of the element

getFirstValue

protected XMLCatalogImpl.CatalogEntry getFirstValue(EName element)

Returns the first value that is associated with the specified name.

Parameters:

element - the expanded name of the element

Returns:

the first value

getFirstValue

protected XMLCatalogImpl.CatalogEntry getFirstValue(EName element,
                                                    EName attributeEName,
                                                    String attributeValue)

Returns the first element that is associated with the specified name and attribute.

Parameters:

element - the expanded name of the element

attributeEName - the expanded attribute name

attributeValue - the attribute value

Returns:

the first value

getFirstLocalizedValue

protected XMLCatalogImpl.CatalogEntry getFirstLocalizedValue(EName element,
                                                             String language)

Returns the first value that is associated with the specified name and language.

Parameters:

element - the expanded name of the element

language - the language identifier or null to get only elements without xml:lang attribute

Returns:

the first value

getFirstTypedValue

protected XMLCatalogImpl.CatalogEntry getFirstTypedValue(EName element,
                                                         String type)

Returns the first value that is associated with the specified name and language.

Parameters:

element - the expanded name of the element

type - the xsi:type value

Returns:

the element

equal

protected boolean equal(Object a,
                        Object b)

Tests two objects for equality.

newDocument

protected Document newDocument()
                        throws ParserConfigurationException

Creates an xml document root and returns it.

Returns:

the document

Throws:

ParserConfigurationException - If the xml parser environment is not correctly configured

saveToXml

protected void saveToXml(Node document,
                         String docType,
                         OutputStream out)
                  throws TransformerException,
                         IOException

Serializes the given xml document to the associated file. Please note that this method does not close the output stream. Anyone using this method is responsible for doing it by itself.

Parameters:

document - the document

docType - the document type definition (dtd)

Throws:

TransformerException - if serialization fails

IOException

toManifest

public Node toManifest(Document document,
                       MediaPackageSerializer serializer)
                throws MediaPackageException

Description copied from interface: ManifestContributor

This method returns an XML serialization of the object to be stored in the media package manifest. It should be possible to reconstruct the object from this data.

For creating MediaPackageElements from a manifest, please use MediaPackageElementBuilder.elementFromManifest(org.w3c.dom.Node, MediaPackageSerializer). All other objects shall provide their own implementation specific reconstruction mechanism.

Specified by:

toManifest in interface ManifestContributor

Overrides:

toManifest in class AbstractMediaPackageElement

Parameters:

document - the parent

serializer - the media package serializer

Returns:

the object's xml representation

Throws:

MediaPackageException - if the mediapackage can't be serialized

See Also:

AbstractMediaPackageElement.toManifest(org.w3c.dom.Document, org.opencastproject.mediapackage.MediaPackageSerializer)

getPrefix

protected String getPrefix(String namespaceURI)

Get a prefix from bindings but throw a NamespaceBindingException if none found.

includeEmpty

public void includeEmpty(boolean includeEmpty)

Description copied from interface: XMLCatalog

Marshal elements with empty values to support remove existing values during catalog merge.

Specified by:

includeEmpty in interface XMLCatalog

See Also:

XMLCatalog.includeEmpty(boolean)

toQName

protected String toQName(EName eName)

Transform an expanded name to a qualified name based on the registered binding.

Parameters:

eName - the expanded name to transform

Returns:

the qualified name, e.g. dcterms:title

Throws:

NamespaceBindingException - if the namespace name is not bound to a prefix

toEName

protected EName toEName(String prefix,
                        String localName)

Transform an qualified name consisting of prefix and local part to an expanded name, based on the registered binding.

Parameters:

prefix - the prefix

localName - the local part

Returns:

the expanded name

Throws:

NamespaceBindingException - if the namespace name is not bound to a prefix

toEName

protected EName toEName(String qName)

Transform a qualified name to an expanded name, based on the registered binding.

Parameters:

qName - the qualified name, e.g. dcterms:title or title

Returns:

the expanded name

Throws:

NamespaceBindingException - if the namespace name is not bound to a prefix

toXml

public void toXml(OutputStream out,
                  boolean format)
           throws IOException

Writes an xml representation of this Catalog to a stream.

Specified by:

toXml in interface XMLCatalog

Parameters:

out - The output stream

format - Whether to format the output for readability, or not (false gives better performance)

Throws:

IOException

See Also:

XMLCatalog.toXml(java.io.OutputStream, boolean)

toXmlString

public String toXmlString()
                   throws IOException

Writes an xml representation of this Catalog to a string.

Specified by:

toXmlString in interface XMLCatalog

Returns:

the Catalog serialized to a string

Throws:

IOException

See Also:

XMLCatalog.toXmlString()