org.dspace.ctask.general

Class MetadataWebService

java.lang.Object

org.dspace.curate.AbstractCurationTask

org.dspace.ctask.general.MetadataWebService

All Implemented Interfaces:

NamespaceContext, CurationTask

@Mutative
@Suspendable
public class MetadataWebService
extends AbstractCurationTask
implements NamespaceContext

MetadataWebService task calls a web service using metadata from passed item to obtain data. Depending on configuration, this data may be assigned to item metadata fields, or just recorded in the task result string. Task succeeds if web service call succeeds and configured updates occur, fails if task user not authorized or item lacks metadata to call service, and returns error in all other cases (except skip status for non-item objects). Intended use: cataloging tool in workflow and general curation. The task uses a URL 'template' to compose the service call, e.g. http://www.sherpa.ac.uk/romeo/api29.php?issn={dc.identifier.issn} Task will substitute the value of the passed item's metadata field in the {parameter} position. If multiple values are present in the item field, the first value is used. The task uses another property (the datamap) to determine what data to extract from the service response and how to use it, e.g. //publisher/name=>dc.publisher,//romeocolour Task will evaluate the left-hand side (or entire token) of each comma-separated token in the property as an XPath 1.0 expression into the response document, and if there is a mapping symbol (e.g.'=>') and value, it will assign the response document value(s) to the named metadata field in the passed item. If the response document contains multiple values, they will all be assigned to the item field. The mapping symbol governs the nature of metadata field assignment: '->' mapping will add to any existing values in the item field '=>' mapping will replace any existing values in the item field '~>' mapping will add *only* if item field has no existing values Unmapped data (without a mapping symbol) will simply be added to the task result string, prepended by the XPath expression (a little prettified). Each label/value pair in the result string is separated by a space, unless the optional 'separator' property is defined. A very rudimentary facility for transformation of data is supported, e.g. http://www.crossref.org/openurl/?id={doi:dc.relation.isversionof}&format=unixref The 'doi:' prefix will cause the task to look for a 'transform' with that name, which is applied to the metadata value before parameter substitution occurs. Transforms are defined in a task property such as the following: transform.doi = match 10. trunc 60 This means exclude the value string up to the occurrence of '10.', then truncate after 60 characters. The only transform functions currently defined: 'cut' = remove number leading characters 'trunc' = remove trailing characters after number length 'match' = start match at pattern 'text' = append literal characters (enclose in ' ' when whitespace needed) If the transform results in an invalid state (e.g. cutting more characters than are in the value), the condition will be logged and the un-transformed value used. Transforms may also be used in datamaps, e.g. //publisher/name=>shorten:dc.publisher,//romeocolour which would apply the 'shorten' transform to the service response value(s) prior to metadata field assignment. An optional property 'headers' may be defined to stipulate any HTTP headers required in the service call. The property syntax is double-pipe separated headers: Accept: text/xml||Cache-Control: no-cache

Author:

richardrodgers

Field Summary

Fields

Modifier and Type	Field and Description
protected List<MetadataWebServiceDataInfo>	dataList
protected DocumentBuilder	docBuilder
protected String	fieldSeparator
protected Map<String,String>	headers
protected String	lang
protected String	lookupField
protected String	lookupTransform
protected Map<String,String>	nsMap
protected String	templateParam
protected Pattern	ttPattern
protected String	urlTemplate

Fields inherited from class org.dspace.curate.AbstractCurationTask

communityService, configurationService, curator, handleService, itemService, taskId

Constructor Summary

Constructors

Constructor and Description
MetadataWebService()

Method Summary

Methods

Modifier and Type	Method and Description
protected int	callService(String value, Item item, StringBuilder resultSb)
protected void	checkNamespaces(Document document)
protected int	getMapIndex(String mapping)
String	getNamespaceURI(String prefix)
String	getPrefix(String uri)
Iterator	getPrefixes(String uri)
void	init(Curator curator, String taskId) Initializes task
protected String	mangleExpr(String expr, String prefix)
protected String[]	parseTransform(String field)
int	perform(DSpaceObject dso) Perform the curation task upon passed DSO
protected int	processResponse(Document doc, Item item, StringBuilder resultSb)
protected String[]	tokenize(String text)
protected String	transform(String value, String transDef)

Methods inherited from class org.dspace.curate.AbstractCurationTask

dereference, distribute, perform, performItem, performObject, report, setResult, taskArrayProperty, taskBooleanProperty, taskIntProperty, taskLongProperty, taskProperty

Methods inherited from class java.lang.Object

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

Field Detail

ttPattern

protected Pattern ttPattern

urlTemplate

protected String urlTemplate

templateParam

protected String templateParam

lookupField

protected String lookupField

lookupTransform

protected String lookupTransform

dataList

protected List<MetadataWebServiceDataInfo> dataList

docBuilder

protected DocumentBuilder docBuilder

lang

protected String lang

fieldSeparator

protected String fieldSeparator

nsMap

protected Map<String,String> nsMap

headers

protected Map<String,String> headers

Constructor Detail

MetadataWebService

public MetadataWebService()

Method Detail

init

public void init(Curator curator,
        String taskId)
          throws IOException

Initializes task

Specified by:

init in interface CurationTask

Overrides:

init in class AbstractCurationTask

Parameters:

curator - Curator object performing this task

taskId - the configured local name of the task

Throws:

IOException

perform

public int perform(DSpaceObject dso)
            throws IOException

Perform the curation task upon passed DSO

Specified by:

perform in interface CurationTask

Specified by:

perform in class AbstractCurationTask

Parameters:

dso - the DSpace object

Returns:

status code

Throws:

IOException

callService

protected int callService(String value,
              Item item,
              StringBuilder resultSb)
                   throws IOException

Throws:

IOException

processResponse

protected int processResponse(Document doc,
                  Item item,
                  StringBuilder resultSb)
                       throws IOException

Throws:

IOException

transform

protected String transform(String value,
               String transDef)

tokenize

protected String[] tokenize(String text)

getMapIndex

protected int getMapIndex(String mapping)

parseTransform

protected String[] parseTransform(String field)

checkNamespaces

protected void checkNamespaces(Document document)
                        throws IOException

Throws:

IOException

mangleExpr

protected String mangleExpr(String expr,
                String prefix)

getNamespaceURI

public String getNamespaceURI(String prefix)

Specified by:

getNamespaceURI in interface NamespaceContext

getPrefix

public String getPrefix(String uri)

Specified by:

getPrefix in interface NamespaceContext

getPrefixes

public Iterator getPrefixes(String uri)

Specified by:

getPrefixes in interface NamespaceContext