MODLD-957: Hub preview API

NEWS.md

@@ -84,6 +84,7 @@
 - Include tenant ID in cache [MODLD-952](https://folio-org.atlassian.net/browse/MODLD-952)
 - Handle free form language text values in HUBs in GET, PUT /resource APIs [MODLD-977](https://folio-org.atlassian.net/browse/MODLD-977)
 - Index modified Hubs in mod-search [MODLD-969](https://folio-org.atlassian.net/browse/MODLD-969)
+- Hub preview API [MODLD-957](https://folio-org.atlassian.net/browse/MODLD-957)
 
 ## 1.0.4 (04-24-2025)
 - Work Edit form - Instance read-only section: "Notes about the instance" data is not shown [MODLD-716](https://folio-org.atlassian.net/browse/MODLD-716)

README.md

@@ -271,6 +271,10 @@ curl --location '{{ base-uri }}/linked-data/resource/{id}/graph' \
 --header 'x-okapi-tenant: {tenant}' \
 --header 'x-okapi-token: {token}'
 ```
+
+### Preview of a remote Hub resource
+A preview of a remote Hub resource can be retrieved by making a GET request to the `/linked-data/hub` endpoint with the Hub URI as a query parameter.
+
 # Integration with FOLIO
 When running in FOLIO mode, this module integrates with multiple Folio modules via Kafka.
 ## Search module

descriptors/ModuleDescriptor-template.json

@@ -108,6 +108,12 @@
             "source-storage.records.formatted.item.get",
             "search.authorities.collection.get"
           ]
+        },
+        {
+          "methods": [ "GET" ],
+          "pathPattern": "/linked-data/hub",
+          "permissionsRequired": [ "linked-data.hub.preview.get" ],
+          "modulePermissions": []
         }
       ]
     },
@@ -300,6 +306,11 @@
       "permissionName": "linked-data.resources.rdf.get",
       "displayName": "Linked Data: Export an Instance to RDF JSON-LD",
       "description": "Export an Instance to RDF JSON-LD"
+    },
+    {
+      "permissionName": "linked-data.hub.preview.get",
+      "displayName": "Linked Data: Get the preview of a remote Hub resource",
+      "description": "Get the preview of a remote Hub resource by Hub URI"
     }
   ],
   "launchDescriptor": {

src/main/java/org/folio/linked/data/configuration/RestClientConfiguration.java

@@ -0,0 +1,17 @@
+package org.folio.linked.data.configuration;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.client.JdkClientHttpRequestFactory;
+import org.springframework.web.client.RestClient;
+
+@Configuration
+public class RestClientConfiguration {
+
+  @Bean
+  public RestClient restClient() {
+    return RestClient.builder()
+      .requestFactory(new JdkClientHttpRequestFactory())
+      .build();
+  }
+}

src/main/java/org/folio/linked/data/controller/HubController.java

@@ -0,0 +1,21 @@
+package org.folio.linked.data.controller;
+
+import lombok.RequiredArgsConstructor;
+import org.folio.linked.data.domain.dto.ResourceResponseDto;
+import org.folio.linked.data.rest.resource.HubApi;
+import org.folio.linked.data.service.hub.HubService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequiredArgsConstructor
+public class HubController implements HubApi {
+
+  private final HubService hubService;
+
+  @Override
+  public ResponseEntity<ResourceResponseDto> getHubPreviewByUri(String hubUri) {
+    return ResponseEntity.ok(hubService.previewHub(hubUri));
+  }
+
+}

src/main/java/org/folio/linked/data/exception/RequestProcessingExceptionBuilder.java

@@ -48,6 +48,11 @@ public RequestProcessingException notFoundSourceRecordException(String idType, S
     return requestProcessingException(notFoundError, "Source Record", idType, idValue, "Source Record storage");
   }
 
+  public RequestProcessingException notFoundHubByUriException(String hubUri) {
+    var notFoundError = errorResponseConfig.getNotFound();
+    return requestProcessingException(notFoundError, "Hub", "URI", hubUri, "remote source");
+  }
+
   public RequestProcessingException failedDependencyException(String message, String reason) {
     return requestProcessingException(errorResponseConfig.getFailedDependency(), message, reason);
   }

src/main/java/org/folio/linked/data/integration/http/HttpClient.java

@@ -0,0 +1,19 @@
+package org.folio.linked.data.integration.http;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestClient;
+
+@Component
+@RequiredArgsConstructor
+public class HttpClient {
+
+  private final RestClient restClient;
+
+  public String downloadString(String url) {
+    return restClient.get()
+      .uri(url)
+      .retrieve()
+      .body(String.class);
+  }
+}

src/main/java/org/folio/linked/data/service/hub/HubService.java

@@ -0,0 +1,9 @@
+package org.folio.linked.data.service.hub;
+
+import org.folio.linked.data.domain.dto.ResourceResponseDto;
+
+public interface HubService {
+
+  ResourceResponseDto previewHub(String hubUri);
+
+}

src/main/java/org/folio/linked/data/service/hub/HubServiceImpl.java

@@ -0,0 +1,41 @@
+package org.folio.linked.data.service.hub;
+
+import static org.apache.commons.lang3.StringUtils.substringAfterLast;
+import static org.apache.commons.lang3.StringUtils.substringBefore;
+import static org.folio.ld.dictionary.PropertyDictionary.LINK;
+import static org.folio.linked.data.mapper.dto.resource.base.SingleResourceMapperUnit.ResourceMappingContext;
+import static org.folio.linked.data.util.ResourceUtils.getPropertyValues;
+
+import lombok.RequiredArgsConstructor;
+import org.folio.linked.data.domain.dto.ResourceResponseDto;
+import org.folio.linked.data.exception.RequestProcessingExceptionBuilder;
+import org.folio.linked.data.integration.http.HttpClient;
+import org.folio.linked.data.mapper.dto.resource.hub.HubMapperUnit;
+import org.folio.linked.data.service.rdf.RdfImportService;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class HubServiceImpl implements HubService {
+
+  private final HttpClient httpClient;
+  private final HubMapperUnit hubMapperUnit;
+  private final RdfImportService rdfImportService;
+  private final RequestProcessingExceptionBuilder requestProcessingExceptionBuilder;
+
+  @Override
+  public ResourceResponseDto previewHub(String hubUri) {
+    var jsonString = httpClient.downloadString(hubUri);
+    var imported = rdfImportService.importRdfJsonString(jsonString, false);
+    var id = substringBefore(substringAfterLast(hubUri, "/"), ".");
+    return imported.stream()
+      .filter(r -> getPropertyValues(r, LINK).stream().anyMatch(p -> p.contains(id)))
+      .map(hubResource -> {
+        var rmc = new ResourceMappingContext(null, null);
+        return hubMapperUnit.toDto(hubResource, new ResourceResponseDto(), rmc);
+      })
+      .findFirst()
+      .orElseThrow(() -> requestProcessingExceptionBuilder.notFoundHubByUriException(hubUri));
+  }
+
+}

src/main/java/org/folio/linked/data/service/rdf/RdfImportService.java

@@ -1,8 +1,10 @@
 package org.folio.linked.data.service.rdf;
 
 import java.time.OffsetDateTime;
+import java.util.Set;
 import org.folio.linked.data.domain.dto.ImportFileResponseDto;
 import org.folio.linked.data.domain.dto.ImportOutputEvent;
+import org.folio.linked.data.model.entity.Resource;
 import org.springframework.web.multipart.MultipartFile;
 
 public interface RdfImportService {
@@ -11,4 +13,6 @@ public interface RdfImportService {
 
   void importOutputEvent(ImportOutputEvent event, OffsetDateTime startTime);
 
+  Set<Resource> importRdfJsonString(String rdfJson, Boolean save);
+
 }

src/main/java/org/folio/linked/data/service/rdf/RdfImportServiceImpl.java

@@ -1,14 +1,25 @@
 package org.folio.linked.data.service.rdf;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.stream.Collectors.toSet;
+import static org.folio.linked.data.util.ImportUtils.APPLICATION_LD_JSON_VALUE;
+import static org.folio.linked.data.util.ImportUtils.ImportReport;
+import static org.folio.linked.data.util.ImportUtils.ImportedResource;
+import static org.folio.linked.data.util.ImportUtils.Status;
+import static org.folio.linked.data.util.ImportUtils.Status.CONVERTED;
 import static org.folio.linked.data.util.ImportUtils.Status.CREATED;
 import static org.folio.linked.data.util.ImportUtils.Status.FAILED;
 import static org.folio.linked.data.util.ImportUtils.Status.UPDATED;
+import static org.folio.linked.data.util.ImportUtils.toRdfMediaType;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.time.OffsetDateTime;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicLong;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.log4j.Log4j2;
 import org.folio.linked.data.domain.dto.ImportFileResponseDto;
@@ -18,10 +29,10 @@
 import org.folio.linked.data.exception.RequestProcessingExceptionBuilder;
 import org.folio.linked.data.mapper.ResourceModelMapper;
 import org.folio.linked.data.mapper.kafka.ldimport.ImportEventResultMapper;
+import org.folio.linked.data.model.entity.Resource;
 import org.folio.linked.data.service.lccn.LccnResourceService;
 import org.folio.linked.data.service.resource.graph.ResourceGraphService;
 import org.folio.linked.data.service.resource.meta.MetadataService;
-import org.folio.linked.data.util.ImportUtils;
 import org.folio.rdf4ld.service.Rdf4LdService;
 import org.folio.spring.tools.kafka.FolioMessageProducer;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -50,9 +61,7 @@ public class RdfImportServiceImpl implements RdfImportService {
   @Override
   public ImportFileResponseDto importFile(MultipartFile multipartFile) {
     try (var is = multipartFile.getInputStream()) {
-      var resources = rdf4LdService.mapBibframe2RdfToLd(is, ImportUtils.toRdfMediaType(multipartFile.getContentType()));
-      var resourcesWithLineNumbers = resources.stream().map(r -> new ResourceWithLineNumber(1L, r)).collect(toSet());
-      var importReport = doImport(resourcesWithLineNumbers);
+      var importReport = importInputStream(is, toRdfMediaType(multipartFile.getContentType()), true);
       var reportCsv = importReport.toCsv();
       return new ImportFileResponseDto(importReport.getIdsWithStatus(CREATED, UPDATED), reportCsv);
     } catch (IOException e) {
@@ -66,13 +75,35 @@ public ImportFileResponseDto importFile(MultipartFile multipartFile) {
   @Override
   @Transactional(propagation = Propagation.REQUIRES_NEW)
   public void importOutputEvent(ImportOutputEvent event, OffsetDateTime startTime) {
-    var report = doImport(event.getResourcesWithLineNumbers());
+    var report = doImport(event.getResourcesWithLineNumbers(), true);
     var importEventResult = importEventResultMapper.fromImportReport(event, startTime, report);
     importResultEventProducer.sendMessages(List.of(importEventResult));
   }
 
-  private ImportUtils.ImportReport doImport(Set<ResourceWithLineNumber> resourcesWithLineNumbers) {
-    var report = new ImportUtils.ImportReport();
+  @Override
+  public Set<Resource> importRdfJsonString(String rdfJson, Boolean save) {
+    try (var inputStream = new ByteArrayInputStream(rdfJson.getBytes(UTF_8))) {
+      var importReport = importInputStream(inputStream, APPLICATION_LD_JSON_VALUE, save);
+      return importReport.getImports().stream()
+        .map(ImportedResource::getResourceEntity)
+        .filter(Objects::nonNull)
+        .collect(toSet());
+    } catch (IOException e) {
+      throw exceptionBuilder.badRequestException("Rdf JSON import error", e.getMessage());
+    }
+  }
+
+  private ImportReport importInputStream(InputStream input, String contentType, Boolean save) {
+    var resources = rdf4LdService.mapBibframe2RdfToLd(input, contentType);
+    var lineNumber = new AtomicLong(1);
+    var resourcesWithLineNumbers = resources.stream()
+      .map(r -> new ResourceWithLineNumber(lineNumber.getAndIncrement(), r))
+      .collect(toSet());
+    return doImport(resourcesWithLineNumbers, save);
+  }
+
+  private ImportReport doImport(Set<ResourceWithLineNumber> resourcesWithLineNumbers, boolean save) {
+    var report = new ImportReport();
     var mockResourcesSearchResult = lccnResourceService.findMockResources(
       resourcesWithLineNumbers.stream().map(ResourceWithLineNumber::getResource).collect(toSet())
     );
@@ -82,12 +113,17 @@ private ImportUtils.ImportReport doImport(Set<ResourceWithLineNumber> resourcesW
           mockResourcesSearchResult);
         var resource = resourceModelMapper.toEntity(resourceModel);
         metadataService.ensure(resource);
-        var saveGraphResult = resourceGraphService.saveMergingGraphInNewTransaction(resource);
-        var status = saveGraphResult.newResources().contains(resource) ? CREATED : UPDATED;
-        report.addImport(new ImportUtils.ImportedResource(resourceWithLineNumber, status, null));
+        Status status;
+        if (save) {
+          var saveGraphResult = resourceGraphService.saveMergingGraphInNewTransaction(resource);
+          status = saveGraphResult.newResources().contains(resource) ? CREATED : UPDATED;
+        } else {
+          status = CONVERTED;
+        }
+        report.addImport(new ImportedResource(resourceWithLineNumber, status, null, resource));
       } catch (Exception e) {
         log.debug("Exception during import of a resource from line {}", resourceWithLineNumber.getLineNumber(), e);
-        report.addImport(new ImportUtils.ImportedResource(resourceWithLineNumber, FAILED, e.getMessage()));
+        report.addImport(new ImportedResource(resourceWithLineNumber, FAILED, e.getMessage(), null));
       }
     });
     return report;

src/main/java/org/folio/linked/data/util/ImportUtils.java

@@ -15,8 +15,8 @@
 import lombok.extern.log4j.Log4j2;
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVPrinter;
-import org.folio.ld.dictionary.model.Resource;
 import org.folio.linked.data.domain.dto.ResourceWithLineNumber;
+import org.folio.linked.data.model.entity.Resource;
 
 @Log4j2
 @UtilityClass
@@ -55,6 +55,7 @@ private enum ReportHeader {
   public enum Status {
     CREATED("Created"),
     UPDATED("Updated"),
+    CONVERTED("Converted"),
     FAILED("Failed");
 
     private final String value;
@@ -67,15 +68,18 @@ public static class ImportedResource {
     private Long lineNumber;
     private Status status;
     private String failureReason;
-    private Resource failedResource;
+    private Resource resourceEntity;
 
-    public ImportedResource(ResourceWithLineNumber resourceWithLineNumber, Status status, String failureReason) {
+    public ImportedResource(ResourceWithLineNumber resourceWithLineNumber,
+                            Status status,
+                            String failureReason,
+                            Resource resourceEntity) {
       this.id = resourceWithLineNumber.getResource().getId();
       this.label = resourceWithLineNumber.getResource().getLabel();
       this.lineNumber = resourceWithLineNumber.getLineNumber();
       this.status = status;
       this.failureReason = failureReason;
-      this.failedResource = status == FAILED ? resourceWithLineNumber.getResource() : null;
+      this.resourceEntity = resourceEntity;
     }
   }
 

src/main/resources/swagger.api/mod-linked-data.yaml

@@ -451,6 +451,26 @@ paths:
         '500':
           $ref: '#/components/responses/internalServerErrorResponse'
 
+  /linked-data/hub:
+    get:
+      operationId: getHubPreviewByUri
+      tags:
+        - hub
+      description: Get the preview of a remote Hub resource
+      parameters:
+        - $ref: '#/components/parameters/hubUri'
+      responses:
+        '200':
+          description: Resource as json string
+          content:
+            application/json:
+              schema:
+                $ref: schema/resourceResponseDto.json
+        '404':
+          description: No Hub resource is found by Hub URI
+        '500':
+          $ref: '#/components/responses/internalServerErrorResponse'
+
 components:
   parameters:
     id:
@@ -491,6 +511,13 @@ components:
       schema:
         type: integer
         format: int16
+    hubUri:
+      name: hubUri
+      in: query
+      required: true
+      description: URI of a remote Hub resource
+      schema:
+        type: string
   schemas:
     errorResponse:
       $ref: schema/error/errors.json