Fix LazyInitializationException for all lazy collections in MediaModel (virtual threads)

src/main/java/com/espacogeek/geek/data/impl/GenericMediaDataControllerImpl.java

@@ -32,6 +32,7 @@
 import com.espacogeek.geek.services.GenreService;
 import com.espacogeek.geek.services.MediaService;
 import com.espacogeek.geek.services.SeasonService;
+import com.espacogeek.geek.utils.MediaLazyLoader;
 
 import jakarta.persistence.Id;
 import jakarta.persistence.ManyToMany;
@@ -48,20 +49,23 @@ public class GenericMediaDataControllerImpl implements MediaDataController {
     private final AlternativeTitlesService alternativeTitlesService;
     private final ExternalReferenceService externalReferenceService;
     private final SeasonService seasonService;
+    private final MediaLazyLoader mediaLazyLoader;
 
     @Autowired
     public GenericMediaDataControllerImpl(
             @Lazy MediaService mediaService,
             GenreService genreService,
             AlternativeTitlesService alternativeTitlesService,
             ExternalReferenceService externalReferenceService,
-            SeasonService seasonService
+            SeasonService seasonService,
+            MediaLazyLoader mediaLazyLoader
     ) {
         this.mediaService = mediaService;
         this.genreService = genreService;
         this.alternativeTitlesService = alternativeTitlesService;
         this.externalReferenceService = externalReferenceService;
         this.seasonService = seasonService;
+        this.mediaLazyLoader = mediaLazyLoader;
     }
 
     public GenericMediaDataControllerImpl getInstance() {
@@ -73,6 +77,8 @@ public GenericMediaDataControllerImpl getInstance() {
      */
     @Override
     public MediaModel updateAllInformation(MediaModel media, MediaModel result, TypeReferenceModel typeReference, MediaApi mediaApi) {
+        mediaLazyLoader.initializeCollections(media);
+
         if (result == null) {
             Collection<ExternalReferenceModel> externalReferences = media.getExternalReference();
             if (externalReferences == null || !Hibernate.isInitialized(externalReferences)) {

src/main/java/com/espacogeek/geek/data/impl/MovieControllerImpl.java

@@ -28,6 +28,7 @@
 import com.espacogeek.geek.services.MediaCategoryService;
 import com.espacogeek.geek.services.SeasonService;
 import com.espacogeek.geek.services.TypeReferenceService;
+import com.espacogeek.geek.utils.MediaLazyLoader;
 
 import jakarta.annotation.PostConstruct;
 
@@ -51,9 +52,10 @@ public MovieControllerImpl(
             GenreService genreService,
             AlternativeTitlesService alternativeTitlesService,
             ExternalReferenceService baseExternalReferenceService,
-            SeasonService seasonService
+            SeasonService seasonService,
+            MediaLazyLoader mediaLazyLoader
     ) {
-        super(mediaService, genreService, alternativeTitlesService, baseExternalReferenceService, seasonService);
+        super(mediaService, genreService, alternativeTitlesService, baseExternalReferenceService, seasonService, mediaLazyLoader);
         this.movieAPI = movieAPI;
         this.mediaCategoryService = mediaCategoryService;
         this.externalReferenceService = externalReferenceService;

src/main/java/com/espacogeek/geek/data/impl/SerieControllerImpl.java

@@ -8,6 +8,7 @@
 import java.util.List;
 
 import com.espacogeek.geek.services.*;
+import com.espacogeek.geek.utils.MediaLazyLoader;
 import lombok.extern.slf4j.Slf4j;
 import org.json.simple.JSONObject;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -33,8 +34,8 @@ public class SerieControllerImpl extends GenericMediaDataControllerImpl {
 
     private TypeReferenceModel typeReference;
 
-    public SerieControllerImpl(MediaService mediaService, GenreService genreService, AlternativeTitlesService alternativeTitlesService, ExternalReferenceService externalReferenceService, SeasonService seasonService, MediaApi tvSeriesApi, MediaCategoryService mediaCategoryService, ExternalReferenceService externalReferenceService1, TypeReferenceService typeReferenceService) {
-        super(mediaService, genreService, alternativeTitlesService, externalReferenceService, seasonService);
+    public SerieControllerImpl(MediaService mediaService, GenreService genreService, AlternativeTitlesService alternativeTitlesService, ExternalReferenceService externalReferenceService, SeasonService seasonService, MediaApi tvSeriesApi, MediaCategoryService mediaCategoryService, ExternalReferenceService externalReferenceService1, TypeReferenceService typeReferenceService, MediaLazyLoader mediaLazyLoader) {
+        super(mediaService, genreService, alternativeTitlesService, externalReferenceService, seasonService, mediaLazyLoader);
         this.tvSeriesApi = tvSeriesApi;
         this.mediaCategoryService = mediaCategoryService;
         this.externalReferenceService = externalReferenceService1;

src/main/java/com/espacogeek/geek/repositories/AlternativeTitlesRepository.java

@@ -12,6 +12,8 @@
 @Repository
 public interface AlternativeTitlesRepository extends JpaRepository<AlternativeTitleModel, Integer> {
 
+    List<AlternativeTitleModel> findByMedia(MediaModel media);
+
     List<AlternativeTitleModel> findByMediaIn(Collection<MediaModel> medias);
 
 }

src/main/java/com/espacogeek/geek/repositories/GenreRepository.java

@@ -3,11 +3,16 @@
 import java.util.List;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import com.espacogeek.geek.models.GenreModel;
 
 @Repository
 public interface GenreRepository extends JpaRepository<GenreModel, Integer> {
     public List<GenreModel> findAllByNameIn(List<String> nameGenres);
+
+    @Query("SELECT g FROM MediaModel m JOIN m.genre g WHERE m.id = :mediaId")
+    List<GenreModel> findByMediaId(@Param("mediaId") Integer mediaId);
 }

src/main/java/com/espacogeek/geek/repositories/SeasonRepository.java

@@ -12,6 +12,8 @@
 @Repository
 public interface SeasonRepository extends JpaRepository<SeasonModel, Integer> {
 
+    List<SeasonModel> findByMedia(MediaModel media);
+
     List<SeasonModel> findByMediaIn(Collection<MediaModel> medias);
 
 }

src/main/java/com/espacogeek/geek/services/AlternativeTitlesService.java

@@ -5,7 +5,10 @@
 import org.springframework.dao.DataIntegrityViolationException;
 
 import com.espacogeek.geek.models.AlternativeTitleModel;
+import com.espacogeek.geek.models.MediaModel;
 
 public interface AlternativeTitlesService {
     public List<AlternativeTitleModel> saveAll(List<AlternativeTitleModel> alternativeTitles) throws DataIntegrityViolationException;
+
+    public List<AlternativeTitleModel> findAll(MediaModel media);
 }

src/main/java/com/espacogeek/geek/services/GenreService.java

@@ -3,9 +3,12 @@
 import java.util.List;
 
 import com.espacogeek.geek.models.GenreModel;
+import com.espacogeek.geek.models.MediaModel;
 
 public interface GenreService {
     public List<GenreModel> findAllByNames(List<String> names);
 
+    public List<GenreModel> findAll(MediaModel media);
+
     public List<GenreModel> saveAll(List<GenreModel> genres);
 }

src/main/java/com/espacogeek/geek/services/SeasonService.java

@@ -2,8 +2,11 @@
 
 import java.util.List;
 
+import com.espacogeek.geek.models.MediaModel;
 import com.espacogeek.geek.models.SeasonModel;
 
 public interface SeasonService {
     public List<SeasonModel> saveAll(List<SeasonModel> seasons);
+
+    public List<SeasonModel> findAll(MediaModel media);
 }

src/main/java/com/espacogeek/geek/services/impl/AlternativeTitlesServiceImpl.java

@@ -7,6 +7,7 @@
 import org.springframework.stereotype.Service;
 
 import com.espacogeek.geek.models.AlternativeTitleModel;
+import com.espacogeek.geek.models.MediaModel;
 import com.espacogeek.geek.repositories.AlternativeTitlesRepository;
 import com.espacogeek.geek.services.AlternativeTitlesService;
 
@@ -18,4 +19,9 @@ public class AlternativeTitlesServiceImpl implements AlternativeTitlesService {
     public List<AlternativeTitleModel> saveAll(List<AlternativeTitleModel> alternativeTitles) throws DataIntegrityViolationException {
         return alternativeTitlesRepository.saveAll(alternativeTitles);
     }
+
+    @Override
+    public List<AlternativeTitleModel> findAll(MediaModel media) {
+        return alternativeTitlesRepository.findByMedia(media);
+    }
 }

src/main/java/com/espacogeek/geek/services/impl/GenreServiceImpl.java

@@ -6,6 +6,7 @@
 import org.springframework.stereotype.Service;
 
 import com.espacogeek.geek.models.GenreModel;
+import com.espacogeek.geek.models.MediaModel;
 import com.espacogeek.geek.repositories.GenreRepository;
 import com.espacogeek.geek.services.GenreService;
 
@@ -23,6 +24,14 @@ public List<GenreModel> findAllByNames(List<String> names) {
         return genreRepository.findAllByNameIn(names);
     }
 
+    /**
+     * @see GenreService#findAll(MediaModel)
+     */
+    @Override
+    public List<GenreModel> findAll(MediaModel media) {
+        return genreRepository.findByMediaId(media.getId());
+    }
+
     /**
      * @see GenreService#saveAll(List<GenreModel>)
      */

src/main/java/com/espacogeek/geek/services/impl/MediaServiceImpl.java

@@ -1,10 +1,6 @@
 package com.espacogeek.geek.services.impl;
 
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.ThreadLocalRandom;
@@ -31,13 +27,10 @@
 import com.espacogeek.geek.types.MediaPage;
 import com.espacogeek.geek.types.MediaSimplefied;
 import com.espacogeek.geek.utils.MediaUtils;
-import jakarta.persistence.ManyToMany;
-import jakarta.persistence.OneToMany;
+import com.espacogeek.geek.utils.MediaLazyLoader;
 import jakarta.transaction.Transactional;
 import org.hibernate.Hibernate;
 
-import static com.espacogeek.geek.utils.TextUtils.capitalize;
-
 /**
  * A Implementation class of MediaService @see MediaService
  */
@@ -69,6 +62,8 @@ public class MediaServiceImpl implements MediaService {
     @Qualifier("tvSeriesApi")
     private final MediaApi tvSeriesApi;
 
+    private final MediaLazyLoader mediaLazyLoader;
+
     public MediaServiceImpl(
             MediaRepository mediaRepository,
             ExternalReferenceRepository externalsRepo,
@@ -78,7 +73,8 @@ public MediaServiceImpl(
             TypeReferenceService typeReferenceService,
             @Qualifier("gamesAndVNsAPI") MediaApi gamesAndVNsAPI,
             @Qualifier("movieAPI") MediaApi movieAPI,
-            @Qualifier("tvSeriesApi") MediaApi tvSeriesApi
+            @Qualifier("tvSeriesApi") MediaApi tvSeriesApi,
+            MediaLazyLoader mediaLazyLoader
     ) {
         this.mediaRepository = mediaRepository;
         this.externalsRepo = externalsRepo;
@@ -89,6 +85,7 @@ public MediaServiceImpl(
         this.gamesAndVNsAPI = gamesAndVNsAPI;
         this.movieAPI = movieAPI;
         this.tvSeriesApi = tvSeriesApi;
+        this.mediaLazyLoader = mediaLazyLoader;
     }
 
     /**
@@ -175,31 +172,12 @@ public Optional<MediaModel> findByReferenceAndTypeReference(ExternalReferenceMod
     @Override
     @Transactional
     public Optional<MediaModel> findByIdEager(Integer id) {
-        var fieldList = new ArrayList<Field>();
         MediaModel media = (MediaModel) mediaRepository.findById(id).orElse(null);
 
         if (media == null)
             return Optional.empty();
 
-        for (Field field : media.getClass().getDeclaredFields()) {
-            field.setAccessible(true);
-            if (field.isAnnotationPresent(OneToMany.class) || field.isAnnotationPresent(ManyToMany.class)) {
-                fieldList.add(field);
-            }
-        }
-
-        for (Field field : fieldList) {
-            try {
-                String getterName = "get" + capitalize(field.getName());
-                Method getter = media.getClass().getMethod(getterName);
-                var fieldValue = getter.invoke(media);
-                if (fieldValue instanceof Collection) {
-                    ((Collection<?>) fieldValue).size(); // This will initialize the collection
-                }
-            } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
-                log.error("Failed to initialize field {} for media id={}: {}", field.getName(), media.getId(), e.getMessage());
-            }
-        }
+        mediaLazyLoader.initializeCollections(media);
 
         media = update(media);
 

src/main/java/com/espacogeek/geek/services/impl/SeasonServiceImpl.java

@@ -5,6 +5,7 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+import com.espacogeek.geek.models.MediaModel;
 import com.espacogeek.geek.models.SeasonModel;
 import com.espacogeek.geek.repositories.SeasonRepository;
 import com.espacogeek.geek.services.SeasonService;
@@ -18,4 +19,9 @@ public class SeasonServiceImpl implements SeasonService {
     public List<SeasonModel> saveAll(List<SeasonModel> seasons) {
         return seasonRepository.saveAll(seasons);
     }
+
+    @Override
+    public List<SeasonModel> findAll(MediaModel media) {
+        return seasonRepository.findByMedia(media);
+    }
 }

src/main/java/com/espacogeek/geek/utils/MediaLazyLoader.java

@@ -0,0 +1,75 @@
+package com.espacogeek.geek.utils;
+
+import java.util.LinkedHashSet;
+
+import org.hibernate.Hibernate;
+import org.springframework.stereotype.Component;
+
+import com.espacogeek.geek.models.MediaModel;
+import com.espacogeek.geek.services.AlternativeTitlesService;
+import com.espacogeek.geek.services.ExternalReferenceService;
+import com.espacogeek.geek.services.GenreService;
+import com.espacogeek.geek.services.SeasonService;
+
+/**
+ * Utility Spring bean that guarantees all lazy-loaded {@code Set<>} collections
+ * of a {@link MediaModel} are available for use outside an active Hibernate session.
+ *
+ * <p>With Java 21 virtual threads, thread-local Hibernate sessions can be closed
+ * before update methods finish processing a detached entity, causing
+ * {@code LazyInitializationException}. This class solves the problem once and for all
+ * by checking {@link Hibernate#isInitialized} for every lazy collection and falling
+ * back to a fresh repository query when the session is no longer active.
+ *
+ * <p>Covered collections: {@code externalReference}, {@code alternativeTitles},
+ * {@code genre}, {@code season}.
+ */
+@Component
+public class MediaLazyLoader {
+
+    private final ExternalReferenceService externalReferenceService;
+    private final AlternativeTitlesService alternativeTitlesService;
+    private final GenreService genreService;
+    private final SeasonService seasonService;
+
+    public MediaLazyLoader(
+            ExternalReferenceService externalReferenceService,
+            AlternativeTitlesService alternativeTitlesService,
+            GenreService genreService,
+            SeasonService seasonService) {
+        this.externalReferenceService = externalReferenceService;
+        this.alternativeTitlesService = alternativeTitlesService;
+        this.genreService = genreService;
+        this.seasonService = seasonService;
+    }
+
+    /**
+     * Ensures all lazy {@link java.util.Set} collections of the given {@link MediaModel}
+     * are initialized. For each collection that is {@code null} or not yet initialized
+     * by Hibernate (e.g., because the session that loaded the entity has been closed),
+     * the data is loaded directly from the corresponding service and set back on the entity.
+     *
+     * @param media the {@link MediaModel} to initialize; no-op when {@code null} or unsaved
+     */
+    public void initializeCollections(MediaModel media) {
+        if (media == null || media.getId() == null) {
+            return;
+        }
+
+        if (media.getExternalReference() == null || !Hibernate.isInitialized(media.getExternalReference())) {
+            media.setExternalReference(new LinkedHashSet<>(externalReferenceService.findAll(media)));
+        }
+
+        if (media.getAlternativeTitles() == null || !Hibernate.isInitialized(media.getAlternativeTitles())) {
+            media.setAlternativeTitles(new LinkedHashSet<>(alternativeTitlesService.findAll(media)));
+        }
+
+        if (media.getGenre() == null || !Hibernate.isInitialized(media.getGenre())) {
+            media.setGenre(new LinkedHashSet<>(genreService.findAll(media)));
+        }
+
+        if (media.getSeason() == null || !Hibernate.isInitialized(media.getSeason())) {
+            media.setSeason(new LinkedHashSet<>(seasonService.findAll(media)));
+        }
+    }
+}