edu.UCL.xmiddle.host
Class XPathLinkTable

java.lang.Object
  |
  +--edu.UCL.xmiddle.host.XPathLinkTable

All Implemented Interfaces:

LinkTable

public class XPathLinkTable

extends java.lang.Object

implements LinkTable

XPathLinkTable.java A linktable implemented using hashtables, vectors and a lot of sweat! It basically uses three hashtables (with the application ID of the local application as key) to represent the exports, linked From and linkedBy tables. The hashtables hold Vectors of LinkTableItem. Created: Mon Jul 30 14:07:09 2001

Constructor Summary

XPathLinkTable()
Constructs a new XPathLinkTable for the local host

XPathLinkTable(boolean local)
Constructs a new LinkTable

XPathLinkTable(java.lang.String links)
Constructs a new XPathLinkTable with the given data

XPathLinkTable(java.lang.String links, boolean local)
Constructs a new XPathLinkTable with the given data

Method Summary

void	addExport(org.w3c.dom.Element element, java.lang.Integer appID) Adds a new export.
void	addExport(java.lang.String path, java.lang.Integer appID) Adds a new export.
void	addLinkedBy(java.lang.Object primaryID, org.w3c.dom.Element element, java.lang.Integer localAppID) Adds a new entry to the link table to signify that a given element was linked by a given host
void	addLinkedBy(java.lang.Object primaryID, java.lang.String path, java.lang.Integer localAppID) Adds a new entry to the link table to signify that a given element was linked by a given host
void	addLinkedFrom(java.lang.Object primaryID, java.lang.String src, org.w3c.dom.Element dest, java.lang.Integer remoteAppID, java.lang.Integer localAppID) Signifies that the local host has linked an element from a remote host, and adds that to the linktable.
void	addLinkedFrom(java.lang.Object primaryID, java.lang.String src, java.lang.String dest, java.lang.Integer remoteAppID, java.lang.Integer localAppID) Signifies that the local host has linked an element from a remote host, and adds that to the linktable.
java.util.Enumeration	getExportsList() Returns the exports
java.util.Enumeration	getLinkedByHostList(java.lang.Object primaryID) Returns data on all elements linked by the given host.
java.util.Enumeration	getLinkedByList() Returns the linked by table
java.util.Enumeration	getLinkedFromHostList(java.lang.Object primaryID) Returns data on all elements linked from the given host.
java.util.Enumeration	getLinkedFromList() Returns the linked From table
java.lang.String	getLinkTableMessage() Returns an XML representation of the linktable message
boolean	isExported(org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is exported
boolean	isExported(java.lang.String path, java.lang.Integer appID) Determines whether the given element is exported
boolean	isLinkedBy(org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is linked by another host.
boolean	isLinkedBy(java.lang.Object primaryID, org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is linked by a particular host.
boolean	isLinkedBy(java.lang.Object primaryID, java.lang.String path, java.lang.Integer appID) Determines whether the given element is linked by a particular host.
boolean	isLinkedBy(java.lang.String path, java.lang.Integer appID) Determines whether the given element is linked by another host.
boolean	isLinkedFrom(org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is linked from another host.
boolean	isLinkedFrom(java.lang.Object primaryID, org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is linked from a particular host.
boolean	isLinkedFrom(java.lang.Object primaryID, java.lang.String path, java.lang.Integer appID) Determines whether the given element is linked from a particular host.
boolean	isLinkedFrom(java.lang.String path, java.lang.Integer appID) Determines whether the given element is linked from another host.
boolean	isShared(org.w3c.dom.Element element, java.lang.Integer appID) Determines whether the given element is shared with another host.
boolean	isShared(java.lang.String path, java.lang.Integer appID) Determines whether the given element is shared with another host.
void	removeExport(org.w3c.dom.Element element, java.lang.Integer appID) Signifies that the local host has stopped exporting the given element
void	removeExport(java.lang.String path, java.lang.Integer appID) Signifies that the local host has stopped exporting the given element
void	removeLinkedBy(java.lang.Object primaryID, org.w3c.dom.Element element, java.lang.Integer localAppID) Signifies that the given element is not linked from the given host, and removes any such references from the linktable
void	removeLinkedBy(java.lang.Object primaryID, java.lang.String path, java.lang.Integer localAppID) Signifies that the given element is not linked from the given host, and removes any such references from the linktable
void	removeLinkedFrom(org.w3c.dom.Element element, java.lang.Integer appID) Signifies that the given element is not linked from any other host, and removes any such references from the linktable
void	removeLinkedFrom(java.lang.String path, java.lang.Integer appID) Signifies that the given element is not linked from any other host, and removes any such references from the linktable
void	setLinks(java.lang.Object links) Parses an XML string containing the linktable (of a remote host)

Methods inherited from class java.lang.Object

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

Constructor Detail

XPathLinkTable

public XPathLinkTable()

Constructs a new XPathLinkTable for the local host

XPathLinkTable

public XPathLinkTable(java.lang.String links)

Constructs a new XPathLinkTable with the given data

Parameters:

links - The XPathLinkTable in XML format

XPathLinkTable

public XPathLinkTable(boolean local)

Constructs a new LinkTable

Parameters:

local - If true, then the link table is destined for the local host.

XPathLinkTable

public XPathLinkTable(java.lang.String links,
                      boolean local)

Constructs a new XPathLinkTable with the given data

Parameters:

links - The XPathLinkTable in XML format

local - if true, then the link table is destine for the local host

Method Detail

getLinkTableMessage

public java.lang.String getLinkTableMessage()

Returns an XML representation of the linktable message

Specified by:

getLinkTableMessage in interface LinkTable

Returns:

a String value

isShared

public boolean isShared(java.lang.String path,
                        java.lang.Integer appID)

Determines whether the given element is shared with another host. A shared element is an element which is linked from or by another host

Specified by:

isShared in interface LinkTable

Parameters:

path - the element (as an XPath expression)

appID - the ID of the application under the tree of which this element resides

Returns:

true if the element is shared, or false otherwise

isShared

public boolean isShared(org.w3c.dom.Element element,
                        java.lang.Integer appID)

Determines whether the given element is shared with another host. A shared element is an element which is linked from or by another host

Specified by:

isShared in interface LinkTable

Parameters:

element - the element

appID - the ID of the application under the tree of which this element resides

Returns:

true if the element is shared, or false otherwise

isLinkedFrom

public boolean isLinkedFrom(java.lang.String path,
                            java.lang.Integer appID)

Determines whether the given element is linked from another host.

Specified by:

isLinkedFrom in interface LinkTable

Parameters:

path - The element (encoded as an XPath expression)

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked from another host, or false otherwise

isLinkedFrom

public boolean isLinkedFrom(org.w3c.dom.Element element,
                            java.lang.Integer appID)

Determines whether the given element is linked from another host.

Specified by:

isLinkedFrom in interface LinkTable

Parameters:

element - The element

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked from another host, or false otherwise

isLinkedFrom

public boolean isLinkedFrom(java.lang.Object primaryID,
                            java.lang.String path,
                            java.lang.Integer appID)

Determines whether the given element is linked from a particular host.

Specified by:

isLinkedFrom in interface LinkTable

Parameters:

primaryID - the primary ID of the remote host

path - The element (encoded as an XPath expression)

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked from the other host, or false otherwise

isLinkedFrom

public boolean isLinkedFrom(java.lang.Object primaryID,
                            org.w3c.dom.Element element,
                            java.lang.Integer appID)

Determines whether the given element is linked from a particular host.

Specified by:

isLinkedFrom in interface LinkTable

Parameters:

primaryID - the primary ID of the remote host

element - The element

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked from the other host, or false otherwise

isExported

public boolean isExported(java.lang.String path,
                          java.lang.Integer appID)

Determines whether the given element is exported

Specified by:

isExported in interface LinkTable

Parameters:

path - the element encoded as an XPath expression

appID - the id of the application under the tree of which this element resides

Returns:

true if the element is exported, or false otherwise

isExported

public boolean isExported(org.w3c.dom.Element element,
                          java.lang.Integer appID)

Determines whether the given element is exported

Specified by:

isExported in interface LinkTable

Parameters:

element - the element

appID - the id of the application under the tree of which this element resides

Returns:

true if the element is exported, or false otherwise

isLinkedBy

public boolean isLinkedBy(java.lang.Object primaryID,
                          java.lang.String path,
                          java.lang.Integer appID)

Determines whether the given element is linked by a particular host.

Specified by:

isLinkedBy in interface LinkTable

Parameters:

primaryID - the primary ID of the remote host

path - The element encoded as an XPath expression

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked by the other host, or false otherwise

isLinkedBy

public boolean isLinkedBy(java.lang.Object primaryID,
                          org.w3c.dom.Element element,
                          java.lang.Integer appID)

Determines whether the given element is linked by a particular host.

Specified by:

isLinkedBy in interface LinkTable

Parameters:

primaryID - the primary ID of the remote host

element - The element

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked by the other host, or false otherwise

isLinkedBy

public boolean isLinkedBy(java.lang.String path,
                          java.lang.Integer appID)

Determines whether the given element is linked by another host.

Specified by:

isLinkedBy in interface LinkTable

Parameters:

path - element (encoded as an XPath expression)

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked by another host, or false otherwise

isLinkedBy

public boolean isLinkedBy(org.w3c.dom.Element element,
                          java.lang.Integer appID)

Determines whether the given element is linked by another host.

Specified by:

isLinkedBy in interface LinkTable

Parameters:

element - The element

appID - The ID of the application under the tree of which this element resides.

Returns:

true if the element is linked by another host, or false otherwise

addLinkedFrom

public void addLinkedFrom(java.lang.Object primaryID,
                          java.lang.String src,
                          java.lang.String dest,
                          java.lang.Integer remoteAppID,
                          java.lang.Integer localAppID)

Signifies that the local host has linked an element from a remote host, and adds that to the linktable.

Specified by:

addLinkedFrom in interface LinkTable

Parameters:

primaryID - The primary ID of the remote host

src - The remote element which the local host linked from (encoded as XPath)

dest - The local element under which the linked element was placed at (encoded as XPath)

remoteAppID - The id of the remote application that exported the element

localAppID - The id of the local application on the data structure of which the remote element was linked

addLinkedFrom

public void addLinkedFrom(java.lang.Object primaryID,
                          java.lang.String src,
                          org.w3c.dom.Element dest,
                          java.lang.Integer remoteAppID,
                          java.lang.Integer localAppID)

Signifies that the local host has linked an element from a remote host, and adds that to the linktable.

Specified by:

addLinkedFrom in interface LinkTable

Parameters:

primaryID - The primary ID of the remote host

src - The remote element which the local host linked from (encoded as XPath)

dest - The local element under which the linked element was placed

remoteAppID - The id of the remote application that exported the element

localAppID - The id of the local application on the data structure of which the remote element was linked

removeLinkedFrom

public void removeLinkedFrom(java.lang.String path,
                             java.lang.Integer appID)

Signifies that the given element is not linked from any other host, and removes any such references from the linktable

Parameters:

path - The given element (encoded as XPath)

appID - The ID of the application under which this element resides

removeLinkedFrom

public void removeLinkedFrom(org.w3c.dom.Element element,
                             java.lang.Integer appID)

Signifies that the given element is not linked from any other host, and removes any such references from the linktable

Specified by:

removeLinkedFrom in interface LinkTable

Parameters:

element - The given element

appID - The ID of the application under which this element resides

addLinkedBy

public void addLinkedBy(java.lang.Object primaryID,
                        java.lang.String path,
                        java.lang.Integer localAppID)

Adds a new entry to the link table to signify that a given element was linked by a given host

Specified by:

addLinkedBy in interface LinkTable

Parameters:

primaryID - The primaryID of the remote host

path - The element that was linked By the remote host (encoded as XPath)

localAppID - The ID of the application under the tree of which the element that was linked by resides

addLinkedBy

public void addLinkedBy(java.lang.Object primaryID,
                        org.w3c.dom.Element element,
                        java.lang.Integer localAppID)

Adds a new entry to the link table to signify that a given element was linked by a given host

Specified by:

addLinkedBy in interface LinkTable

Parameters:

primaryID - The primaryID of the remote host

element - The element that was linked By the remote host

localAppID - The ID of the application under the tree of which the element that was linked by resides

removeLinkedBy

public void removeLinkedBy(java.lang.Object primaryID,
                           java.lang.String path,
                           java.lang.Integer localAppID)

Signifies that the given element is not linked from the given host, and removes any such references from the linktable

Specified by:

removeLinkedBy in interface LinkTable

Parameters:

primaryID - The primaryID of the remote host

path - The given element (encoded as XPath)

localAppID - The ID of the local application to which the element belonged

removeLinkedBy

public void removeLinkedBy(java.lang.Object primaryID,
                           org.w3c.dom.Element element,
                           java.lang.Integer localAppID)

Signifies that the given element is not linked from the given host, and removes any such references from the linktable

Specified by:

removeLinkedBy in interface LinkTable

Parameters:

primaryID - The primaryID of the remote host

element - The given element

localAppID - The ID of the local application to which the element belonged

addExport

public void addExport(java.lang.String path,
                      java.lang.Integer appID)

Adds a new export.

Specified by:

addExport in interface LinkTable

Parameters:

path - The element to export (encoded as XPath)

appID - The ID of the application under the tree of which the element resides

addExport

public void addExport(org.w3c.dom.Element element,
                      java.lang.Integer appID)

Adds a new export.

Specified by:

addExport in interface LinkTable

Parameters:

element - The element to export

appID - The ID of the application under the tree of which the element resides

removeExport

public void removeExport(java.lang.String path,
                         java.lang.Integer appID)

Signifies that the local host has stopped exporting the given element

Specified by:

removeExport in interface LinkTable

Parameters:

path - The element to stop exporting (Encoded as XPath)

appID - The ID of the application under which the element resides

removeExport

public void removeExport(org.w3c.dom.Element element,
                         java.lang.Integer appID)

Signifies that the local host has stopped exporting the given element

Specified by:

removeExport in interface LinkTable

Parameters:

appID - The ID of the application under which the element resides

element - The Element

setLinks

public void setLinks(java.lang.Object links)

Parses an XML string containing the linktable (of a remote host)

Specified by:

setLinks in interface LinkTable

Parameters:

links - a String representation of the XML-formated version of a linktable. Warning: this method includes no checks. links must be formatted exactly according to the guidelines of getLinkTableMessage() above.

getLinkedFromHostList

public java.util.Enumeration getLinkedFromHostList(java.lang.Object primaryID)

Returns data on all elements linked from the given host.

Specified by:

getLinkedFromHostList in interface LinkTable

Parameters:

primaryID - The primaryID of the host to be checked.

Returns:

An Enumeration containing LinkTableItems. If no elements are linked, then null is returned.

getLinkedByHostList

public java.util.Enumeration getLinkedByHostList(java.lang.Object primaryID)

Returns data on all elements linked by the given host.

Specified by:

getLinkedByHostList in interface LinkTable

Parameters:

primaryID - The primaryID of the host to be checked.

Returns:

An Enumeration containing LinkTableItems. If no elements are linked, or no linkedBy table is present, then null is returned

getLinkedFromList

public java.util.Enumeration getLinkedFromList()

Returns the linked From table

Specified by:

getLinkedFromList in interface LinkTable

Returns:

The structure is as follows: each element in the enumeration is a Vector. The vector holds LinkTableItem objects of type LINKED_FROM

See Also:

LinkTableItem

getLinkedByList

public java.util.Enumeration getLinkedByList()

Returns the linked by table

Specified by:

getLinkedByList in interface LinkTable

Returns:

The structure is as follows: each element in the enumeration is a Vector. The vector holds LinkTableItem objects of type LINKED_BY

See Also:

LinkTableItem

getExportsList

public java.util.Enumeration getExportsList()

Returns the exports

Specified by:

getExportsList in interface LinkTable

Returns:

The structure is as follows: each element in the enumeration is a Vector. The vector holds LinkTableItem objects of type EXPORT

See Also:

LinkTableItem