org.licas.service.resource.info

Class InfoStreamXml

java.lang.Object

org.licas.service.resource.Resource

org.licas.service.resource.info.InfoStreamXml

public class InfoStreamXml
extends Resource

This is used by the InformationService to return a remote stream value parsed into xml. The URL link to the online source is stored and the contents are returned upon request. This should close the stream after each request. The getValue method logs any error but then returns null instead of throwing an exception. An alternative to this would be the InfoHtml resource for more basic HTML pages.

This class tries to read the event stream as an input stream. If that fails, it tries to retrieve the whole stream first as a string, check formatting and then create the event stream. If that fails, it resets SSL to accept any certificate and repeats the process. The TrustManager is then re-loaded at the end if it has been reset.

The default is to parse the stream to format it as an rss feed. As well as the Const.VALUE element, it is possible to add a <Keywords><Keyword>kw1</Keyword><Keyword>kw2</Keyword>...</Keywords> section to the initialisation script to define a different set of element names to keep. In that case, both the data value element and the keywords element probably need to be both wrapped in an outer element.

Author:

Kieran Greer

Field Summary

Fields inherited from class org.licas.service.resource.Resource

dataType, INFOANYTYPE, INFOBINARYTYPE, INFOHTMLTYPE, INFOSTREAMXMLTYPE, INFOSTRINGTYPE, INFOTEXTTYPE, INFOURLTYPE, INFOXMLTYPE, LISTCONTAINERTYPE, QUERYCONTAINERTYPE, RANDOMCONTAINERTYPE, uuid

Constructor Summary

Constructors

Constructor and Description
InfoStreamXml(java.lang.String theDataType, org.licas_xml.abs.Element dataXml) Create a new instance of InfoStreamXml.

Method Summary

Modifier and Type	Method and Description
org.licas_xml.abs.Element	getInfo(org.licas_xml.abs.Element infoDescr) Get the currently loaded source information wrapped in an XML element.
java.lang.String	getURL() Get the url address.
java.lang.Object	getValue(org.licas_xml.abs.Element infoDescr) Get the value itself and not a wrapped description.
boolean	parseInfo(org.licas_xml.abs.Element dataXml) Parse the data description in the document to create the data object.

Methods inherited from class org.licas.service.resource.Resource

createResource, dataFromResourceType, getDataType, getUUID, parseValueElem, resourceTypeForDataType, setUUID, setUUID

Methods inherited from class java.lang.Object

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

Constructor Detail

InfoStreamXml

public InfoStreamXml(java.lang.String theDataType,
                     org.licas_xml.abs.Element dataXml)
              throws java.lang.Exception

Create a new instance of InfoStreamXml.

Parameters:

theDataType - the resource data type. One of the stream types. This returns the stream as a String by default.

dataXml - a description of the initialisation parameters. Can be null.

Throws:

java.lang.Exception - any error.

Method Detail

parseInfo

public boolean parseInfo(org.licas_xml.abs.Element dataXml)
                  throws java.lang.Exception

Parse the data description in the document to create the data object. This version should read a URL address and store that. It also only returns the URL address upon request.

Specified by:

parseInfo in class Resource

Parameters:

dataXml - this must include a Const.VALUE element that stores a String-based URL path description. It can also include a Keywords element that stores a specific list of element tag names to keep. If not present, then a default rss set of element names are kept.

Returns:

true if the file was successfully loaded, false otherwise.

Throws:

java.lang.Exception - any error.

getInfo

public org.licas_xml.abs.Element getInfo(org.licas_xml.abs.Element infoDescr)
                                  throws java.lang.Exception

Get the currently loaded source information wrapped in an XML element.

Specified by:

getInfo in class Resource

Parameters:

infoDescr - a description of the info resource value that should be retrieved.

Returns:

the value of the resource info as an XML element. This format is consistent with adding a Data element through an admin document.

Throws:

java.lang.Exception - any error.

getValue

public java.lang.Object getValue(org.licas_xml.abs.Element infoDescr)
                          throws java.lang.Exception

Get the value itself and not a wrapped description.

Specified by:

getValue in class Resource

Parameters:

infoDescr - a description of the info resource value that should be retrieved. Ignored in this case as the whole source stream, parsed into XML, is returned.

Returns:

the info value.

Throws:

java.lang.Exception - any error.

getURL

public java.lang.String getURL()

Get the url address.

Returns:

the value of url.toExternalForm().