Package org.mycore.mods.merger

Class MCRMerger

java.lang.Object

org.mycore.mods.merger.MCRMerger

Direct Known Subclasses:

MCRAbstractMerger, MCRCategoryMerger, MCRExtentMerger, MCRIdentifierMerger, MCRNameMerger, MCRRelatedItemMerger, MCRTitleInfoMerger, MCRUniqueMerger, MCRUniqueTypeMerger

public class MCRMerger
extends Object

MCRMerger is the main and default implementation for comparing and merging MODS elements that are semantically the same. Each MODS element is wrapped by an instance of MCRMerger or one of its subclasses. It contains methods to decide whether the two MODS elements are equal, or probably represent the information maybe with different granularity. If so, the text, elements and attributes are merged so that the "better" information/representation wins. This is done recursively for all child elements, too.

Author:

Frank Lützenkirchen

Field Summary

Fields

Modifier and Type	Field	Description
protected Element	element	The MODS element wrapped and compared by this merger

Constructor Summary

Constructors

Constructor	Description
MCRMerger()

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)	Two mergers are equal if they wrap elements that are deep equals.
protected List<Element>	getNodes(String xPath)	Helper method to lookup child elements by XPath.
boolean	isProbablySameAs(MCRMerger other)	Returns true, if the element wrapped by this merger probably represents the same information as the other.
protected void	mergeAttributes(MCRMerger other)	Copies those attributes from the other's element into this' element that do not exist in this' element.
protected void	mergeElements(MCRMerger other)	Merges all child elements of this with that from other.
void	mergeFrom(MCRMerger other)	Merges the contents of the element wrapped by the other merger into the contents of the element wrapped by this merger.
void	setElement(Element element)	Sets the MODS element wrapped and compared by this merger

Methods inherited from class java.lang.Object

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

Field Details

element

protected Element element

The MODS element wrapped and compared by this merger

Constructor Details

MCRMerger

public MCRMerger()

Method Details

setElement

public void setElement(Element element)

Sets the MODS element wrapped and compared by this merger

isProbablySameAs

public boolean isProbablySameAs(MCRMerger other)

Returns true, if the element wrapped by this merger probably represents the same information as the other. The default implementation returns false and may be overwritten by subclasses implementing logic for specific MODS elements.

equals

public boolean equals(Object obj)

Two mergers are equal if they wrap elements that are deep equals.

Overrides:

equals in class Object

mergeFrom

public void mergeFrom(MCRMerger other)

Merges the contents of the element wrapped by the other merger into the contents of the element wrapped by this merger. Should only be called if this.isProbablySameAs(other). The default implementation copies all attributes from the other into this if they do not exist in this element. Afterwards it recursively builds mergers for all child elements and compares and eventually merges them too.

mergeAttributes

protected void mergeAttributes(MCRMerger other)

Copies those attributes from the other's element into this' element that do not exist in this' element.

mergeElements

protected void mergeElements(MCRMerger other)

Merges all child elements of this with that from other. This is done by building MCRMerger instances for each child element and comparing them.

getNodes

protected List<Element> getNodes(String xPath)

Helper method to lookup child elements by XPath.

Parameters:

xPath - XPath expression relative to the element wrapped by this merger.

Returns:

a list of elements matching the given XPath