/**
* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of the License
* at:
*
* http://opensource.org/licenses/ecl2.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*
*/
package org.opencastproject.oaipmh.server;
import static java.lang.String.format;
import static org.opencastproject.oaipmh.OaiPmhUtil.toOaiRepresentation;
import static org.opencastproject.oaipmh.OaiPmhUtil.toUtc;
import static org.opencastproject.oaipmh.persistence.QueryBuilder.queryRepo;
import static org.opencastproject.oaipmh.server.Functions.addDay;
import static org.opencastproject.oaipmh.server.Functions.asDate;
import static org.opencastproject.util.data.Monadics.mlist;
import static org.opencastproject.util.data.Option.some;
import static org.opencastproject.util.data.Prelude.unexhaustiveMatch;
import static org.opencastproject.util.data.functions.Misc.chuck;
import org.opencastproject.mediapackage.MediaPackage;
import org.opencastproject.oaipmh.Granularity;
import org.opencastproject.oaipmh.OaiPmhConstants;
import org.opencastproject.oaipmh.OaiPmhUtil;
import org.opencastproject.oaipmh.persistence.OaiPmhDatabase;
import org.opencastproject.oaipmh.persistence.OaiPmhDatabaseException;
import org.opencastproject.oaipmh.persistence.SearchResult;
import org.opencastproject.oaipmh.persistence.SearchResultItem;
import org.opencastproject.oaipmh.util.XmlGen;
import org.opencastproject.util.data.Function;
import org.opencastproject.util.data.Function0;
import org.opencastproject.util.data.Option;
import org.opencastproject.util.data.Predicate;
import org.opencastproject.util.data.Tuple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
/**
* An OAI-PMH protocol compliant repository.
* <p>
* Currently supported:
* <ul>
* <li></li>
* </ul>
* <p>
* Currently <em>not</em> supported:
* <ul>
* <li><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#deletion">deletions</a></li>
* <li><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#Set">sets</a></li>
* <li><about> containers in records, see section <a
* href="http://www.openarchives.org/OAI/openarchivesprotocol.html#Record">2.5. Record</a></li>
* <li>
* resumption tokens do not report about their expiration date; see section <a
* href="http://www.openarchives.org/OAI/openarchivesprotocol.html#FlowControl">3.5. Flow Control</a></li>
* </ul>
*/
// todo - malformed date parameter must produce a BadArgument error - if a date parameter has a finer granularity than
// supported by the repository this must produce a BadArgument error
public abstract class OaiPmhRepository {
private static final Logger logger = LoggerFactory.getLogger(OaiPmhRepository.class);
private static final OaiDcMetadataProvider OAI_DC_METADATA_PROVIDER = new OaiDcMetadataProvider();
private static final String OAI_NS = OaiPmhConstants.OAI_2_0_XML_NS;
public abstract Granularity getRepositoryTimeGranularity();
/** Display name of the OAI-PMH repository. */
public abstract String getRepositoryName();
/** Repository ID. */
public abstract String getRepositoryId();
public abstract OaiPmhDatabase getPersistence();
public abstract String getAdminEmail();
/**
* Save a query.
*
* @return a resumption token
*/
public abstract String saveQuery(ResumableQuery query);
/** Get a saved query. */
public abstract Option<ResumableQuery> getSavedQuery(String resumptionToken);
/** Maximum number of items returned by the list queries ListIdentifiers, ListRecords and ListSets. */
public abstract int getResultLimit();
/**
* Return a list of available metadata providers. Please do not expose the default provider for the
* mandatory oai_dc format since this is automatically added when calling {@link #getMetadataProviders()}.
*
* @see #getMetadataProviders()
*/
public abstract List<MetadataProvider> getRepositoryMetadataProviders();
/** Return the current date. Used in implementation instead of new Date(); to facilitate unit testing. */
public Date currentDate() {
return new Date();
}
/** Return a list of all available metadata providers. The <code>oai_dc</code> format is always included. */
public final List<MetadataProvider> getMetadataProviders() {
return mlist(getRepositoryMetadataProviders()).cons(OAI_DC_METADATA_PROVIDER).value();
}
/** Add an item to the repository. */
public void addItem(MediaPackage mp) {
getPersistence().search(queryRepo(getRepositoryId()).build());
try {
getPersistence().store(mp, getRepositoryId());
} catch (OaiPmhDatabaseException e) {
chuck(e);
}
}
/** Create an OAI-PMH response based on the given request params. */
public XmlGen selectVerb(Params p) {
if (p.isVerbListIdentifiers()) {
return handleListIdentifiers(p);
} else if (p.isVerbListRecords()) {
return handleListRecords(p);
} else if (p.isVerbGetRecord()) {
return handleGetRecord(p);
} else if (p.isVerbIdentify()) {
return handleIdentify(p);
} else if (p.isVerbListMetadataFormats()) {
return handleListMetadataFormats(p);
} else if (p.isVerbListSets()) {
return handleListSets(p);
} else {
return createErrorResponse(
"badVerb", Option.<String>none(), p.getRepositoryUrl(), "Illegal OAI verb or verb is missing.");
}
}
/** Return the metadata provider for a given metadata prefix. */
public Option<MetadataProvider> getMetadataProvider(final String metadataPrefix) {
return mlist(getMetadataProviders()).find(new Predicate<MetadataProvider>() {
@Override
public Boolean apply(MetadataProvider metadataProvider) {
return metadataProvider.getMetadataFormat().getPrefix().equals(metadataPrefix);
}
});
}
/** {@link #getMetadataProvider(String)} as a function. */
private final Function<String, Option<MetadataProvider>> getMetadataProvider = new Function<String, Option<MetadataProvider>>() {
@Override public Option<MetadataProvider> apply(String metadataPrefix) {
return getMetadataProvider(metadataPrefix);
}
};
/** Create the "GetRecord" response. */
private XmlGen handleGetRecord(final Params p) {
if (p.getIdentifier().isNone() || p.getMetadataPrefix().isNone()) {
return createBadArgumentResponse(p);
} else {
for (final MetadataProvider metadataProvider : p.getMetadataPrefix().bind(getMetadataProvider)) {
final SearchResult res = getPersistence()
.search(queryRepo(getRepositoryId()).mediaPackageId(p.getIdentifier()).build());
final List<SearchResultItem> items = res.getItems();
switch (items.size()) {
case 0:
return createIdDoesNotExistResponse(p);
case 1:
final SearchResultItem item = items.get(0);
return new OaiVerbXmlGen(OaiPmhRepository.this, p) {
@Override
public Element create() {
// create the metadata for this item
Element metadata = metadataProvider.createMetadata(OaiPmhRepository.this, item, p.getSet());
return oai(request($a("identifier", p.getIdentifier().get()), metadataPrefixAttr(p)),
verb(record(item, metadata)));
}
};
default:
throw new RuntimeException("ERROR: Search index contains more than one item with id "
+ p.getIdentifier());
}
}
// no metadata provider found
return createCannotDisseminateFormatResponse(p);
}
}
/** Handle the "Identify" request. */
/*<Identify >
<repositoryName>Test OAI Repository</repositoryName>
<baseURL>http://localhost/oaipmh</baseURL>
<protocolVersion>2.0</protocolVersion>
<adminEmail>admin@localhost.org</adminEmail>
<earliestDatestamp>2010-01-01</earliestDatestamp>
<deletedRecord>transient</deletedRecord>
<granularity>YYYY-MM-DD</granularity>
</Identify>*/
private XmlGen handleIdentify(final Params p) {
return new OaiVerbXmlGen(this, p) {
@Override
public Element create() {
return oai(
request(),
verb($eTxt("repositoryName", OAI_NS, getRepositoryName()),
$eTxt("baseURL", OAI_NS, p.getRepositoryUrl()),
$eTxt("protocolVersion", OAI_NS, "2.0"),
$eTxt("adminEmail", OAI_NS, getAdminEmail()),
$eTxt("earliestDatestamp", OAI_NS, "2010-01-01"),
$eTxt("deletedRecord", OAI_NS, "transient"),
$eTxt("granularity", OAI_NS, toOaiRepresentation(getRepositoryTimeGranularity()))));
}
};
}
private XmlGen handleListMetadataFormats(final Params p) {
for (String id : p.getIdentifier()) {
final SearchResult res = getPersistence().search(queryRepo(getRepositoryId()).mediaPackageId(id).build());
if (res.getItems().size() != 1)
return createIdDoesNotExistResponse(p);
}
return new OaiVerbXmlGen(this, p) {
@Override
public Element create() {
final List<Node> metadataFormats = mlist(getMetadataProviders()).map(new Function<MetadataProvider, Node>() {
@Override
public Node apply(MetadataProvider metadataProvider) {
return metadataFormat(metadataProvider.getMetadataFormat());
}
}).value();
return oai(request($aSome("identifier", p.getIdentifier())), verb(metadataFormats));
}
};
}
private XmlGen handleListRecords(final Params p) {
final ListItemsEnv env = new ListItemsEnv() {
@Override
protected ListXmlGen respond(ListGenParams listParams) {
return new ListXmlGen(listParams) {
@Override
protected List<Node> createContent(final Option<String> set) {
return mlist(params.getResult().getItems()).map(new Function<SearchResultItem, Node>() {
@Override
public Node apply(SearchResultItem item) {
final Element metadata = params.getMetadataProvider().createMetadata(OaiPmhRepository.this, item, set);
return record(item, metadata);
}
}).value();
}
};
}
};
return env.apply(p);
}
private XmlGen handleListIdentifiers(final Params p) {
final ListItemsEnv env = new ListItemsEnv() {
@Override
protected ListXmlGen respond(ListGenParams listParams) {
// create XML response
return new ListXmlGen(listParams) {
@Override
protected List<Node> createContent(Option<String> set) {
return mlist(params.getResult().getItems()).map(new Function<SearchResultItem, Node>() {
@Override
public Node apply(SearchResultItem item) {
return header(item);
}
}).value();
}
};
}
};
return env.apply(p);
}
/** Create the "ListSets" response. Since the list is short the complete list is returned at once. */
private XmlGen handleListSets(final Params p) {
return new OaiVerbXmlGen(this, p) {
@Override
public Element create() {
return createNoSetHierarchyResponse(p).create();
// leave to following code in place for the time sets are supported
// // define sets
// @SuppressWarnings("unchecked")
// final List<List<String>> sets = _();
// // map to nodes
// final List<Node> setNodes = mlist(sets).map(new Function<List<String>, Node>() {
// @Override
// public Node apply(List<String> strings) {
// return $e("set", $eTxt("setSpec", strings.get(0)), $eTxt("setName", strings.get(1)),
// $e("setDescription", dc($eTxt("dc:description", strings.get(2)))));
// }
// }).value();
// return oai(request(), verb(setNodes));
}
};
}
// --
private XmlGen createCannotDisseminateFormatResponse(Params p) {
return createErrorResponse(
OaiPmhConstants.ERROR_CANNOT_DISSEMINATE_FORMAT, p.getVerb(), p.getRepositoryUrl(),
"The metadata format identified by the value given for the metadataPrefix argument is not supported by the item or by the repository.");
}
private XmlGen createIdDoesNotExistResponse(Params p) {
return createErrorResponse(
OaiPmhConstants.ERROR_ID_DOES_NOT_EXIST, p.getVerb(), p.getRepositoryUrl(),
format("The requested id %s does not exist in the repository.",
p.getIdentifier().getOrElse("?")));
}
private XmlGen createBadArgumentResponse(Params p) {
return createErrorResponse(OaiPmhConstants.ERROR_BAD_ARGUMENT, p.getVerb(), p.getRepositoryUrl(),
"The request includes illegal arguments or is missing required arguments.");
}
private XmlGen createBadResumptionTokenResponse(Params p) {
return createErrorResponse(
OaiPmhConstants.ERROR_BAD_RESUMPTION_TOKEN, p.getVerb(), p.getRepositoryUrl(),
"The value of the resumptionToken argument is either invalid or expired.");
}
private XmlGen createNoRecordsMatchResponse(Params p) {
return createErrorResponse(
OaiPmhConstants.ERROR_NO_RECORDS_MATCH, p.getVerb(), p.getRepositoryUrl(),
"The combination of the values of the from, until, and set arguments results in an empty list.");
}
private XmlGen createNoSetHierarchyResponse(Params p) {
return createErrorResponse(
OaiPmhConstants.ERROR_NO_SET_HIERARCHY, p.getVerb(), p.getRepositoryUrl(),
"This repository does not support sets");
}
private XmlGen createErrorResponse(
final String code, final Option<String> verb, final String repositoryUrl, final String msg) {
return new OaiXmlGen(this) {
@Override
public Element create() {
return oai($e("request",
OaiPmhConstants.OAI_2_0_XML_NS,
$aSome("verb", verb),
$txt(repositoryUrl)),
$e("error", OaiPmhConstants.OAI_2_0_XML_NS, $a("code", code), $cdata(msg)));
}
};
}
// --
/**
* Convert a date to the repository supported time granularity.
*
* @return the converted date or null if d is null
*/
String toSupportedGranularity(Date d) {
return toUtc(d, getRepositoryTimeGranularity());
}
// CHECKSTYLE:OFF
final Function<Date, String> toSupportedGranularity = new Function<Date, String>() {
@Override
public String apply(Date date) {
return toSupportedGranularity(date);
}
};
// CHECKSTYLE:ON
private final Function<Date, Date> granulate = new Function<Date, Date>() {
@Override
public Date apply(Date date) {
return granulate(getRepositoryTimeGranularity(), date);
}
};
/** "Cut" a date to the repositories supported granularity. Cutting behaves similar to the mathematical floor function. */
public static Date granulate(Granularity g, Date d) {
switch (g) {
case SECOND: {
Calendar c = Calendar.getInstance();
c.setTimeZone(OaiPmhUtil.newDateFormat().getTimeZone());
c.setTime(d);
c.set(Calendar.MILLISECOND, 0);
return c.getTime();
}
case DAY: {
final Calendar c = Calendar.getInstance();
c.setTimeZone(OaiPmhUtil.newDateFormat().getTimeZone());
c.setTime(d);
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
return c.getTime();
}
default:
return unexhaustiveMatch();
}
}
static class BadArgumentException extends RuntimeException {
}
/**
* Environment for the list verbs ListIdentifiers and ListRecords. Handles the boilerplate of getting, validating and
* providing the parameters, creating error responses etc. Call {@link #apply(Params)} to create the XML. Also use
* {@link org.opencastproject.oaipmh.server.OaiPmhRepository.ListItemsEnv.ListXmlGen} for the XML generation.
*/
abstract class ListItemsEnv {
ListItemsEnv() {
}
/** Create the regular response from the given parameters. */
protected abstract ListXmlGen respond(ListGenParams params);
/** Call this method to create the XML. */
public XmlGen apply(final Params p) {
// check parameters
final boolean resumptionTokenExists = p.getResumptionToken().isSome();
final boolean otherParamExists = p.getMetadataPrefix().isSome() || p.getFrom().isSome() || p.getUntil().isSome()
|| p.getSet().isSome();
if (resumptionTokenExists && otherParamExists || !resumptionTokenExists && !otherParamExists)
return createBadArgumentResponse(p);
final Option<Date> from = p.getFrom().map(asDate).map(granulate);
final Function<Date, Date> untilAdjustment = getRepositoryTimeGranularity() == Granularity.DAY ? addDay(1)
: org.opencastproject.util.data.functions.Functions.<Date>identity();
final Option<Date> untilGranularity = p.getUntil().map(asDate).map(granulate).map(untilAdjustment);
for (Tuple<Date, Date> fromUntil : from.and(untilGranularity)) {
if (!fromUntil.getA().before(fromUntil.getB())) {
return createBadArgumentResponse(p);
}
}
if (otherParamExists && p.getMetadataPrefix().isNone())
return createBadArgumentResponse(p);
// <- params are ok
final Option<Date> until = untilGranularity.orElse(some(currentDate()));
final String metadataPrefix = p.getResumptionToken().flatMap(getMetadataPrefixFromToken)
.getOrElse(getMetadataPrefix(p));
for (MetadataProvider metadataProvider : p.getResumptionToken()
.flatMap(getMetadataProviderFromToken)
.orElse(getMetadataProvider.curry(metadataPrefix))) {
try {
final SearchResult result;
@SuppressWarnings("unchecked")
final Option<String>[] set = new Option[]{p.getSet()};
if (!resumptionTokenExists) {
// start a new query
result = getPersistence().search(
queryRepo(getRepositoryId())
.modifiedAfter(from)
.modifiedBefore(until)
.limit(getResultLimit()).build());
} else {
// resume query
result = getSavedQuery(p.getResumptionToken().get()).fold(new Option.Match<ResumableQuery, SearchResult>() {
@Override
public SearchResult some(ResumableQuery rq) {
set[0] = rq.getSet();
return getPersistence().search(
queryRepo(getRepositoryId())
.modifiedAfter(rq.getLastResult())
.modifiedBefore(rq.getUntil())
.limit(getResultLimit())
.subsequentRequest(true).build());
}
@Override
public SearchResult none() {
// no resumable query found
throw new BadResumptionTokenException();
}
});
}
if (result.size() > 0) {
return respond(new ListGenParams(OaiPmhRepository.this,
result,
metadataProvider,
metadataPrefix,
p.getResumptionToken(),
from, until.get(),
set[0],
p));
} else {
return createNoRecordsMatchResponse(p);
}
} catch (BadResumptionTokenException e) {
return createBadResumptionTokenResponse(p);
}
}
// no metadata provider found
return createCannotDisseminateFormatResponse(p);
}
/** Get a metadata prefix from a resumption token. */
private final Function<String, Option<String>> getMetadataPrefixFromToken = new Function<String, Option<String>>() {
@Override
public Option<String> apply(String token) {
return getSavedQuery(token).map(new Function<ResumableQuery, String>() {
@Override
public String apply(ResumableQuery resumableQuery) {
return resumableQuery.getMetadataPrefix();
}
});
}
};
/** Get a metadata provider from a resumption token. */
private final Function<String, Option<MetadataProvider>> getMetadataProviderFromToken = new Function<String, Option<MetadataProvider>>() {
@Override
public Option<MetadataProvider> apply(String token) {
return getSavedQuery(token).flatMap(new Function<ResumableQuery, Option<MetadataProvider>>() {
@Override
public Option<MetadataProvider> apply(ResumableQuery resumableQuery) {
return getMetadataProvider(resumableQuery.getMetadataPrefix());
}
});
}
};
/** Get the metadata prefix lazily. */
private Function0<String> getMetadataPrefix(final Params p) {
return new Function0<String>() {
@Override
public String apply() {
return p.getMetadataPrefix().getOrElse(OaiPmhConstants.OAI_DC_METADATA_FORMAT.getPrefix());
}
};
}
/** OAI XML response generation environment for list responses. */
abstract class ListXmlGen extends OaiVerbXmlGen {
protected final ListGenParams params;
ListXmlGen(ListGenParams p) {
super(p.getRepository(), p.getParams());
this.params = p;
}
/** Implement to create your content. Gets placed as children of the verb node. */
protected abstract List<Node> createContent(Option<String> set);
@Override
public Element create() {
final List<Node> content = new ArrayList<Node>(createContent(params.getSet()));
if (content.size() == 0)
return createNoRecordsMatchResponse(params.getParams()).create();
content.add(resumptionToken(params.getResumptionToken(), params.getMetadataPrefix(), params.getResult(),
params.getUntil(), params.getSet()));
return oai(
request($a("metadataPrefix", params.getMetadataPrefix()),
$aSome("from", params.getFrom().map(toSupportedGranularity)),
$aSome("until", some(toSupportedGranularity(params.getUntil()))),
$aSome("set", params.getSet())), verb(content));
}
}
private class BadResumptionTokenException extends RuntimeException {
}
}
}
/** Parameter holder for the list generator. */
final class ListGenParams {
private final OaiPmhRepository repository;
private final SearchResult result;
private final MetadataProvider metadataProvider;
private final String metadataPrefix;
private final Option<String> resumptionToken;
private final Option<Date> from;
private final Date until;
private final Option<String> set;
private final Params params;
// CHECKSTYLE:OFF
ListGenParams(OaiPmhRepository repository,
SearchResult result, MetadataProvider metadataProvider,
String metadataPrefix, Option<String> resumptionToken,
Option<Date> from, Date until,
Option<String> set,
Params params) {
this.repository = repository;
this.result = result;
this.metadataProvider = metadataProvider;
this.resumptionToken = resumptionToken;
this.metadataPrefix = metadataPrefix;
this.from = from;
this.until = until;
this.set = set;
this.params = params;
}
// CHECKSTYLE:ON
public OaiPmhRepository getRepository() {
return repository;
}
public SearchResult getResult() {
return result;
}
public MetadataProvider getMetadataProvider() {
return metadataProvider;
}
public Option<String> getResumptionToken() {
return resumptionToken;
}
public String getMetadataPrefix() {
return metadataPrefix;
}
public Option<Date> getFrom() {
return from;
}
public Date getUntil() {
return until;
}
public Option<String> getSet() {
return set;
}
/** The request parameters. */
public Params getParams() {
return params;
}
}