uoa-validator-engine2

This engine validates metadata records against OpenAIRE's Guidelines. It supports both XML records (OAI-PMH harvested) and JSON documents (e.g. Crossref Works API responses).

It relies on model definitions from the uoa-validator-engine2-result-models software, included as a dependency.

Supported Profiles

XML Profiles (OAI-PMH / DataCite / Dublin Core)

Profile class	Guideline set	Description
LiteratureGuidelinesV4Profile	OpenAIRE Literature v4	Full 32-guideline validation of literature repository records.
LiteratureGuidelinesV3Profile	OpenAIRE Literature v3	Legacy v3 validation.
FAIR_Literature_GuidelinesV4Profile	FAIR Literature v4	FAIR-principle checks derived from the Literature v4 guidelines.
FAIR_Literature_GuidelinesV3Profile	FAIR Literature v3	FAIR-principle checks derived from the Literature v3 guidelines.
DataArchiveGuidelinesV2Profile	OpenAIRE Data v2	Validation of data archive records.
FAIR_Data_GuidelinesProfile	FAIR Data	FAIR-principle checks for data records.
CrisPublicationV111Profile …	OpenAIRE CRIS v1.1.1	Eleven CRIS entity profiles (Publication, Project, Person, OrgUnit, etc.).

JSON Profiles

Profile class	Source format	Description
CrossrefApiV4Profile	Crossref Works API	Full 32-guideline OpenAIRE Literature v4 validation for Crossref JSON documents. See details below.
DataCiteApiV4Profile	DataCite REST API	Full 32-guideline OpenAIRE Literature v4 validation for DataCite JSON documents. See details below.
DcatDataV4Profile	DCAT / JSON-LD	Validation of DCAT dataset metadata (OpenAIRE Data Guidelines v4).
SchemaOrgProfile	Schema.org JSON	Minimal schema.org validation (name, author).

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CrossrefApiV4Profile

eu.dnetlib.validator2.validation.json.CrossrefApiV4Profile

A comprehensive JSON validation profile that maps all 32 OpenAIRE Literature v4 guidelines to Crossref Works API JSON document fields. It is the JSON counterpart of LiteratureGuidelinesV4Profile.

Guideline mapping

#	Guideline	Requirement level	Crossref JSON field(s)	Notes
1	Title	MANDATORY	$.title	Non-empty string array.
2	Creator	MANDATORY	$.author (fallback $.editor)	At least one contributor entry.
3	Contributor	MANDATORY_IF_APPLICABLE	$.editor, $.contributor	Validated when present; each entry must have a name.
4	Funding Reference	MANDATORY_IF_APPLICABLE	$.funder	Validated when present; each funder must have name.
5	Alternate Identifier	RECOMMENDED	$.ISSN, $.ISBN, $.alternative-id	Passes when all three are absent.
6	Related Identifier	RECOMMENDED	$.relation	Non-empty relation object when present.
7	Embargo Period Date	MANDATORY_IF_APPLICABLE	—	Not available in Crossref API; always passes.
8	Publication Date	MANDATORY	$.issued, $.created, $.published-online, $.published-print	Year extracted from date-parts.
9	Language	MANDATORY_IF_APPLICABLE	$.language	ISO 639-1 string; validated when present.
10	Publisher	MANDATORY_IF_APPLICABLE	$.publisher	Non-empty string; validated when present.
11	Resource Type	MANDATORY	$.type	Must be a known Crossref type (see vocabulary below).
12	Description	MANDATORY_IF_APPLICABLE	$.abstract	Non-empty string; validated when present.
13	Format	RECOMMENDED	$.link[*].content-type	At least one MIME-type entry when $.link is present.
14	Resource Identifier	MANDATORY	$.DOI	Primary persistent identifier.
15	Access Rights	MANDATORY_IF_APPLICABLE	—	Not available in Crossref API; always passes.
16	Source	RECOMMENDED	$.source, $.container-title	Passes when both are absent.
17	Subject	MANDATORY_IF_APPLICABLE	$.subject	Non-empty array; validated when present.
18	License Condition	RECOMMENDED	$.license[*].URL	At least one entry with a URL; passes when absent.
19	Coverage	RECOMMENDED	—	Not available in Crossref API; always passes.
20	Size	OPTIONAL	—	Not available in Crossref API; always passes.
21	Geo Location	OPTIONAL	—	Not available in Crossref API; always passes.
22	Resource Version	RECOMMENDED	—	Not a standard Crossref field; always passes.
23	File Location	MANDATORY_IF_APPLICABLE	$.link	Each link must have a non-empty URL; validated when present.
24	Citation Title	RECOMMENDED	$.container-title	Validated when present; passes when absent.
25	Citation Volume	RECOMMENDED	$.volume	Validated when present; passes when absent.
26	Citation Issue	RECOMMENDED	$.issue	Validated when present; passes when absent.
27	Citation Start Page	RECOMMENDED	$.page	Extracted as the part before - in start-end format.
28	Citation End Page	RECOMMENDED	$.page	Extracted as the part after -; passes if no range present.
29	Citation Edition	RECOMMENDED	$.edition-number	Validated when present; passes when absent.
30	Citation Conference Place	RECOMMENDED	$.event.location	Validated when $.event is present.
31	Citation Conference Date	RECOMMENDED	$.event.start	Year extracted from date-parts; validated when $.event is present.
32	Audience	OPTIONAL	—	Not available in Crossref API; always passes.

Crossref type vocabulary (guideline 11)

The $.type value is validated against the official Crossref type vocabulary and mapped to the corresponding OpenAIRE/COAR resource type category:

Crossref type(s)	OpenAIRE general type
journal-article, book, book-chapter, proceedings-article, edited-book, monograph, report, dissertation, peer-review, posted-content, reference-entry, …	literature
dataset	dataset
software	software
component, grant, standard, standard-series, other	other research product

Behavior conventions

• RECOMMENDED fields: follow the same "pass when absent, validate when present" convention as forRecommendedRepeatableElement in the XML profiles — absence does not reduce the score.
• MANDATORY_IF_APPLICABLE fields not available in the Crossref API (rows 7, 15) use a predicate that always returns true, meaning they are treated as not applicable and always pass.
• Access Rights (#15): the OpenAIRE spec designates this as MANDATORY; since the Crossref API does not carry access-rights data, the guideline is modelled as MANDATORY_IF_APPLICABLE (always passes) to avoid penalising valid Crossref records for data their source cannot provide.
• Publication date: the profile accepts any of the four Crossref date fields (issued, created, published-online, published-print) and requires only that a year can be extracted from the date-parts array.

Usage example

import com.jayway.jsonpath.DocumentContext;
import eu.dnetlib.validator2.result_models.ValidationResult;
import eu.dnetlib.validator2.validation.json.CrossrefApiV4Profile;
import eu.dnetlib.validator2.validation.json.JsonUtils;

String crossrefJson = /* fetch from https://api.crossref.org/works/{doi} */;
DocumentContext dc = JsonUtils.parse(crossrefJson);

CrossrefApiV4Profile profile = new CrossrefApiV4Profile();
ValidationResult result = profile.validate("10.1234/example", dc);

System.out.printf("Score: %.1f %%\n", result.getScore());
result.getResults().forEach((name, r) ->
    System.out.printf("  %-30s %s\n", name, r.getStatus()));

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DataCiteApiV4Profile

eu.dnetlib.validator2.validation.json.DataCiteApiV4Profile

A comprehensive JSON validation profile that maps all 32 OpenAIRE Literature V4 guidelines to DataCite REST API attributes object fields. It is the JSON counterpart of LiteratureGuidelinesV4Profile for DataCite-hosted records.

Expected input: pass the data.attributes object (not the full API response wrapper) to validate().

Because DataCite's metadata schema is the same one used by OpenAIRE, the mapping is nearly one-to-one. DataCite carries rich information for fields that are absent in Crossref: Access Rights, Size, Geo Location, Resource Version, Embargo Period dates, and most citation fields via $.container.

Guideline mapping

#	Guideline	Requirement level	DataCite attributes field(s)	Notes
1	Title	MANDATORY	$.titles[*].title	At least one non-empty title.
2	Creator	MANDATORY	$.creators[*].name / givenName+familyName	At least one creator with a name.
3	Contributor	MANDATORY_IF_APPLICABLE	$.contributors	Each entry needs name + contributorType.
4	Funding Reference	MANDATORY_IF_APPLICABLE	$.fundingReferences	Each entry needs funderName.
5	Alternate Identifier	RECOMMENDED	$.alternateIdentifiers (v4.5+) / $.identifiers (legacy)	Passes when absent.
6	Related Identifier	RECOMMENDED	$.relatedIdentifiers	Each entry needs relatedIdentifier, relatedIdentifierType, relationType.
7	Embargo Period Date	MANDATORY_IF_APPLICABLE	$.dates[dateType=Available/Accepted]	Applicable when Available date exists; both dates must be ISO 8601.
8	Publication Date	MANDATORY	$.publicationYear or $.dates[dateType=Issued]	Year integer or ISO 8601 date.
9	Language	MANDATORY_IF_APPLICABLE	$.language	Validated when present.
10	Publisher	MANDATORY_IF_APPLICABLE	$.publisher (string or {name})	Supports legacy string and v4.5+ object format.
11	Resource Type	MANDATORY	$.types.resourceTypeGeneral	Must be a known DataCite type (see vocabulary below).
12	Description	MANDATORY_IF_APPLICABLE	$.descriptions[*].description	At least one non-empty description.
13	Format	RECOMMENDED	$.formats[*]	MIME-type strings; passes when absent.
14	Resource Identifier	MANDATORY	$.doi	Primary persistent identifier.
15	Access Rights	MANDATORY	$.rightsList	Must be present and non-empty (COAR access right entries expected).
16	Source	RECOMMENDED	$.container.title	Passes when $.container is absent.
17	Subject	MANDATORY_IF_APPLICABLE	$.subjects[*].subject	At least one non-empty subject.
18	License Condition	RECOMMENDED	$.rightsList[*].rightsUri	At least one entry with a URI; passes when absent.
19	Coverage	RECOMMENDED	—	No DataCite equivalent; always passes.
20	Size	OPTIONAL	$.sizes[*]	Non-empty string array; validated when present.
21	Geo Location	OPTIONAL	$.geoLocations[*]	Each entry must have at least one geo sub-field.
22	Resource Version	RECOMMENDED	$.version	Validated when present; passes when absent.
23	File Location	MANDATORY_IF_APPLICABLE	$.url	Landing page URL; validated when present.
24	Citation Title	RECOMMENDED	$.container.title	Validated when present; passes when absent.
25	Citation Volume	RECOMMENDED	$.container.volume	Validated when present; passes when absent.
26	Citation Issue	RECOMMENDED	$.container.issue	Validated when present; passes when absent.
27	Citation Start Page	RECOMMENDED	$.container.firstPage	Validated when present; passes when absent.
28	Citation End Page	RECOMMENDED	$.container.lastPage	Validated when present; passes when absent.
29	Citation Edition	RECOMMENDED	—	No container edition field; always passes.
30	Citation Conference Place	RECOMMENDED	—	No dedicated DataCite field; always passes.
31	Citation Conference Date	RECOMMENDED	—	No dedicated DataCite field; always passes.
32	Audience	OPTIONAL	—	No DataCite equivalent; always passes.

DataCite resourceTypeGeneral vocabulary (guideline 11)

DataCite type(s)	OpenAIRE general type
JournalArticle, Book, BookChapter, ConferencePaper, ConferenceProceeding, DataPaper, Dissertation, Journal, PeerReview, Preprint, Report, Text, …	literature
Dataset, DataPaper	dataset
Software, ComputationalNotebook	software
Audiovisual, Collection, Event, Image, Instrument, InteractiveResource, Model, OutputManagementPlan, PhysicalObject, Service, Sound, Standard, StudyRegistration, Workflow, Other	other research product

Behavior conventions

• RECOMMENDED fields: pass when absent, validate when present (same as Crossref profile).
• Embargo Period Date: applicable only when $.dates contains a dateType=Available entry; when applicable both Available and Accepted dates must be valid ISO 8601 (YYYY, YYYY-MM, or YYYY-MM-DD).
• Access Rights (MANDATORY): requires $.rightsList to be present and non-empty. Records without rights information fail this guideline. COAR Access Right concept URIs (open access, embargoed access, restricted access, metadata only access) are the expected values in each entry.
• License Condition (RECOMMENDED): also reads $.rightsList, but checks that at least one entry has a non-empty rightsUri. Passes when $.rightsList is absent.
• Publisher: accepts the legacy string format and the v4.5+ {name: ...} object format.

Usage example

import com.jayway.jsonpath.DocumentContext;
import eu.dnetlib.validator2.result_models.ValidationResult;
import eu.dnetlib.validator2.validation.json.DataCiteApiV4Profile;
import eu.dnetlib.validator2.validation.json.JsonUtils;

// Extract attributes from the DataCite API response:
// String attrJson = fullResponse.get("data").get("attributes").toString();
String attrJson = /* data.attributes JSON string */;
DocumentContext dc = JsonUtils.parse(attrJson);

DataCiteApiV4Profile profile = new DataCiteApiV4Profile();
ValidationResult result = profile.validate("10.1234/example", dc);

System.out.printf("Score: %.1f %%\n", result.getScore());
result.getResults().forEach((name, r) ->
    System.out.printf("  %-30s %s\n", name, r.getStatus()));

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Documentation

• Code Overview: A high-level overview of the most important packages and classes in the project.
• Logic Flow: A detailed description of the validation process, from the entry point to the final result.
• Extending the Engine: A guide on how to create custom rules and profiles.
• Usage Guide: Examples of how to use the validator, both from the command line and programmatically.

Install and run instructions

• Have JDK 8 and maven installed.
• Build with mvn clean install -U.
• Run with java -jar target/uoa-validator-engine2-<VERSION>.jar.

License

This project is licensed under the Apache License, Version 2.0. See the LICENSE.md file for details.