fix(document): remove @BatchSize from @ManyToOne sender — not supported

Hibernate throws AnnotationException at startup when @BatchSize is placed
on a @ManyToOne field. @BatchSize is only valid on collections (@OneToMany,
@ManyToMany, @ElementCollection). The N+1 for sender is already covered by
the @EntityGraph overrides on DocumentRepository.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/main/java/org/raddatz/familienarchiv/document/Document.java

@@ -2,6 +2,7 @@ package org.raddatz.familienarchiv.document;
 
 import jakarta.persistence.*;
 import lombok.*;
+import org.hibernate.annotations.BatchSize;
 import org.hibernate.annotations.CreationTimestamp;
 import org.hibernate.annotations.UpdateTimestamp;
 
@@ -21,6 +22,15 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
 
+@NamedEntityGraph(name = "Document.full", attributeNodes = {
+        @NamedAttributeNode("sender"),
+        @NamedAttributeNode("receivers"),
+        @NamedAttributeNode("tags")
+})
+@NamedEntityGraph(name = "Document.list", attributeNodes = {
+        @NamedAttributeNode("sender"),
+        @NamedAttributeNode("tags")
+})
 @Entity
 @Table(name = "documents")
 @Data // Lombok: Generiert Getter, Setter, ToString, etc.
@@ -118,24 +128,27 @@ public class Document {
     @Builder.Default
     private ScriptType scriptType = ScriptType.UNKNOWN;
 
-    @ManyToMany(fetch = FetchType.EAGER)
+    @ManyToMany(fetch = FetchType.LAZY)
     @JoinTable(name = "document_receivers", joinColumns = @JoinColumn(name = "document_id"), inverseJoinColumns = @JoinColumn(name = "person_id"))
+    @BatchSize(size = 50)
     @Builder.Default
     private Set<Person> receivers = new HashSet<>();
 
-    @ManyToOne
+    @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "sender_id")
     private Person sender;
 
-    @ManyToMany(fetch = FetchType.EAGER)
+    @ManyToMany(fetch = FetchType.LAZY)
     @JoinTable(name = "document_tags", joinColumns = @JoinColumn(name = "document_id"), inverseJoinColumns = @JoinColumn(name = "tag_id"))
+    @BatchSize(size = 50)
     @Builder.Default
     private Set<Tag> tags = new HashSet<>();
 
-    @ElementCollection(fetch = FetchType.EAGER)
+    @ElementCollection(fetch = FetchType.LAZY)
     @CollectionTable(name = "document_training_labels", joinColumns = @JoinColumn(name = "document_id"))
     @Column(name = "label")
     @Enumerated(EnumType.STRING)
+    @BatchSize(size = 50)
     @Builder.Default
     private Set<TrainingLabel> trainingLabels = new HashSet<>();
 

backend/src/main/java/org/raddatz/familienarchiv/document/DocumentRepository.java

@@ -7,6 +7,8 @@ import org.raddatz.familienarchiv.document.DocumentStatus;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 import org.springframework.data.jpa.repository.Query;
@@ -23,6 +25,18 @@ import java.util.UUID;
 @Repository
 public interface DocumentRepository extends JpaRepository<Document, UUID>, JpaSpecificationExecutor<Document> {
 
+    @EntityGraph("Document.full")
+    Optional<Document> findById(UUID id);
+
+    @EntityGraph("Document.list")
+    Page<Document> findAll(Specification<Document> spec, Pageable pageable);
+
+    @EntityGraph("Document.list")
+    List<Document> findAll(Specification<Document> spec);
+
+    @EntityGraph("Document.list")
+    Page<Document> findAll(Pageable pageable);
+
     // Findet ein Dokument anhand des ursprünglichen Dateinamens
     // Wichtig für den Abgleich beim Excel-Import & Datei-Upload
     Optional<Document> findByOriginalFilename(String originalFilename);

backend/src/main/java/org/raddatz/familienarchiv/document/DocumentService.java

@@ -447,6 +447,7 @@ public class DocumentService {
         return saved;
     }
 
+    @Transactional
     public Document updateDocumentTags(UUID docId, List<String> tagNames) {
         Document doc = documentRepository.findById(docId)
                 .orElseThrow(() -> DomainException.notFound(ErrorCode.DOCUMENT_NOT_FOUND, "Document not found: " + docId));
@@ -635,7 +636,9 @@ public class DocumentService {
         return saved;
     }
 
-    // 0. Zuletzt aktive Dokumente (sortiert nach updatedAt DESC)
+    // @Transactional(readOnly=true) keeps the Hibernate session open so the
+    // lazy-loaded sender and tags on returned documents remain accessible to callers.
+    @Transactional(readOnly = true)
     public List<Document> getRecentActivity(int size) {
         return documentRepository.findAll(
                 PageRequest.of(0, size, Sort.by(Sort.Direction.DESC, "updatedAt"))
@@ -843,6 +846,9 @@ public class DocumentService {
         documentRepository.save(doc);
     }
 
+    // @Transactional(readOnly=true) keeps the Hibernate session open so the
+    // lazy-loaded tags and receivers on the returned document remain accessible to callers.
+    @Transactional(readOnly = true)
     public Document getDocumentById(UUID id) {
         Document doc = documentRepository.findById(id)
                 .orElseThrow(() -> DomainException.notFound(ErrorCode.DOCUMENT_NOT_FOUND, "Document not found: " + id));

backend/src/main/java/org/raddatz/familienarchiv/person/Person.java

@@ -1,6 +1,7 @@
 package org.raddatz.familienarchiv.person;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.persistence.*;
 import lombok.*;
@@ -9,6 +10,8 @@ import org.raddatz.familienarchiv.user.DisplayNameFormatter;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
+
+@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
 @Entity
 @Table(name = "persons")
 @Data

backend/src/main/java/org/raddatz/familienarchiv/tag/Tag.java

@@ -2,10 +2,12 @@ package org.raddatz.familienarchiv.tag;
 
 import java.util.UUID;
 
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.persistence.*;
 import lombok.*;
 
+@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
 @Entity
 @Data
 @NoArgsConstructor

backend/src/test/java/org/raddatz/familienarchiv/document/DocumentLazyLoadingTest.java

@@ -0,0 +1,164 @@
+package org.raddatz.familienarchiv.document;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.audit.AuditLogQueryService;
+import org.raddatz.familienarchiv.dashboard.DashboardService;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.raddatz.familienarchiv.tag.TagRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+class DocumentLazyLoadingTest {
+
+    @MockitoBean
+    S3Client s3Client;
+
+    @Autowired
+    DocumentRepository documentRepository;
+
+    @Autowired
+    PersonRepository personRepository;
+
+    @Autowired
+    TagRepository tagRepository;
+
+    @Autowired
+    DocumentService documentService;
+
+    @Autowired
+    DashboardService dashboardService;
+
+    @MockitoBean
+    AuditLogQueryService auditLogQueryService;
+
+    @AfterEach
+    void cleanup() {
+        documentRepository.deleteAll();
+        tagRepository.deleteAll();
+        personRepository.deleteAll();
+    }
+
+    @Test
+    void getDocumentById_tagsAndReceiversAccessible_afterReturnFromService() {
+        Person sender = personRepository.save(Person.builder().firstName("Max").lastName("LzSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("LzReceiver").build());
+        Tag tag = tagRepository.save(Tag.builder().name("LzTag").build());
+        Document doc = documentRepository.save(Document.builder()
+                .title("LazyTest").originalFilename("lazy_test.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        Document result = documentService.getDocumentById(doc.getId());
+
+        assertThatCode(() -> {
+            assertThat(result.getTags()).isNotEmpty();
+            result.getTags().forEach(t -> assertThat(t.getName()).isNotNull());
+            assertThat(result.getReceivers()).isNotEmpty();
+            result.getReceivers().forEach(r -> assertThat(r.getLastName()).isNotNull());
+        }).doesNotThrowAnyException();
+    }
+
+    @Test
+    void getRecentActivity_collectionsAccessibleAfterReturn() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("RaSender").build());
+        Tag tag = tagRepository.save(Tag.builder().name("RaTag").build());
+        for (int i = 0; i < 3; i++) {
+            documentRepository.save(Document.builder()
+                    .title("RaDoc " + i).originalFilename("ra_doc" + i + ".pdf")
+                    .status(DocumentStatus.UPLOADED)
+                    .sender(sender)
+                    .tags(new HashSet<>(Set.of(tag)))
+                    .build());
+        }
+
+        List<Document> results = documentService.getRecentActivity(3);
+
+        assertThatCode(() -> {
+            results.forEach(d -> assertThat(d.getSender()).isNotNull());
+            results.forEach(d -> assertThat(d.getSender().getLastName()).isNotNull());
+            results.forEach(d -> d.getTags().size());
+        }).doesNotThrowAnyException();
+    }
+
+    @Test
+    void searchDocuments_receiverSort_doesNotThrowLazyInitializationException() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("SrSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("SrReceiver").build());
+        Tag tag = tagRepository.save(Tag.builder().name("SrTag").build());
+        documentRepository.save(Document.builder()
+                .title("SrDoc").originalFilename("sr_doc.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        assertThatCode(() -> documentService.searchDocuments(
+                null, null, null, null, null, null, null, null,
+                DocumentSort.RECEIVER, "asc", null,
+                PageRequest.of(0, 20)))
+                .doesNotThrowAnyException();
+    }
+
+    @Test
+    void searchDocuments_senderSort_doesNotThrowLazyInitializationException() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("SsSender").build());
+        Tag tag = tagRepository.save(Tag.builder().name("SsTag").build());
+        documentRepository.save(Document.builder()
+                .title("SsDoc").originalFilename("ss_doc.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        assertThatCode(() -> documentService.searchDocuments(
+                null, null, null, null, null, null, null, null,
+                DocumentSort.SENDER, "asc", null,
+                PageRequest.of(0, 20)))
+                .doesNotThrowAnyException();
+    }
+
+    @Test
+    void dashboardService_getResume_accessesReceiversViaGetDocumentById_withoutException() {
+        Person sender = personRepository.save(Person.builder().firstName("Max").lastName("DsSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("DsReceiver").build());
+        Document doc = documentRepository.save(Document.builder()
+                .title("DashboardTest").originalFilename("dashboard_test.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .build());
+        UUID fakeUserId = UUID.randomUUID();
+        when(auditLogQueryService.findMostRecentDocumentForUser(any())).thenReturn(Optional.of(doc.getId()));
+        when(auditLogQueryService.findRecentContributorsPerDocument(any())).thenReturn(java.util.Map.of());
+
+        assertThatCode(() -> dashboardService.getResume(fakeUserId))
+                .doesNotThrowAnyException();
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/document/DocumentRepositoryTest.java

@@ -1,5 +1,9 @@
 package org.raddatz.familienarchiv.document;
 
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import org.hibernate.SessionFactory;
+import org.hibernate.stat.Statistics;
 import org.junit.jupiter.api.Test;
 import org.raddatz.familienarchiv.PostgresContainerConfig;
 import org.raddatz.familienarchiv.config.FlywayConfig;
@@ -21,6 +25,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.jdbc.test.autoconfigure.AutoConfigureTestDatabase;
 import org.springframework.boot.data.jpa.test.autoconfigure.DataJpaTest;
 import org.springframework.context.annotation.Import;
+import org.springframework.data.jpa.domain.Specification;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -55,6 +60,12 @@ class DocumentRepositoryTest {
     @Autowired
     private TranscriptionBlockRepository transcriptionBlockRepository;
 
+    @Autowired
+    private EntityManagerFactory entityManagerFactory;
+
+    @Autowired
+    private EntityManager entityManager;
+
     // ─── save and findById ────────────────────────────────────────────────────
 
     @Test
@@ -490,6 +501,90 @@ class DocumentRepositoryTest {
         assertThat(ids).containsExactlyInAnyOrder(grandparent.getId(), parent2.getId(), child2.getId());
     }
 
+    // ─── query-count — entity-graph assertions ────────────────────────────────
+
+    @Test
+    void findAll_withSpecAndPageable_loadsDocumentsInAtMostFiveStatements() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("QcSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("QcReceiver").build());
+        Tag tag = tagRepository.save(Tag.builder().name("QcTag").build());
+        for (int i = 0; i < 10; i++) {
+            documentRepository.save(Document.builder()
+                    .title("QcDoc " + i).originalFilename("qcdoc" + i + ".pdf")
+                    .status(DocumentStatus.UPLOADED)
+                    .sender(sender)
+                    .receivers(new HashSet<>(Set.of(receiver)))
+                    .tags(new HashSet<>(Set.of(tag)))
+                    .build());
+        }
+        entityManager.flush();
+        entityManager.clear();
+        Statistics stats = entityManagerFactory.unwrap(SessionFactory.class).getStatistics();
+        stats.setStatisticsEnabled(true);
+        stats.clear();
+
+        Specification<Document> allDocs = (root, query, cb) -> null;
+        documentRepository.findAll(allDocs, PageRequest.of(0, 10));
+
+        assertThat(stats.getPrepareStatementCount())
+                .as("@EntityGraph(Document.list) must load 10 docs in ≤5 statements, not N+1")
+                .isLessThanOrEqualTo(5);
+    }
+
+    @Test
+    void findById_loadsSenderReceiversAndTagsInAtMostTwoStatements() {
+        Person sender = personRepository.save(Person.builder().firstName("Max").lastName("FbSender").build());
+        Set<Person> receivers = new HashSet<>();
+        for (int i = 0; i < 3; i++) {
+            receivers.add(personRepository.save(
+                    Person.builder().firstName("R" + i).lastName("FbReceiver").build()));
+        }
+        Set<Tag> tags = new HashSet<>();
+        for (int i = 0; i < 5; i++) {
+            tags.add(tagRepository.save(Tag.builder().name("FbTag" + i).build()));
+        }
+        Document doc = documentRepository.save(Document.builder()
+                .title("FindByIdQc").originalFilename("findbyid_qc.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender).receivers(receivers).tags(tags)
+                .build());
+        entityManager.flush();
+        entityManager.clear();
+        Statistics stats = entityManagerFactory.unwrap(SessionFactory.class).getStatistics();
+        stats.clear();
+
+        documentRepository.findById(doc.getId());
+
+        assertThat(stats.getPrepareStatementCount())
+                .as("@EntityGraph(Document.full) must load sender+receivers+tags in ≤2 statements, not 4")
+                .isLessThanOrEqualTo(2);
+    }
+
+    @Test
+    void findAll_withPageable_loadsSenderWithoutNPlusOne() {
+        Person sender = personRepository.save(Person.builder().firstName("Maria").lastName("RaSender").build());
+        Tag tag = tagRepository.save(Tag.builder().name("RaTag2").build());
+        for (int i = 0; i < 5; i++) {
+            documentRepository.save(Document.builder()
+                    .title("RaDoc2 " + i).originalFilename("radoc2_" + i + ".pdf")
+                    .status(DocumentStatus.UPLOADED)
+                    .sender(sender)
+                    .tags(new HashSet<>(Set.of(tag)))
+                    .build());
+        }
+        entityManager.flush();
+        entityManager.clear();
+        Statistics stats = entityManagerFactory.unwrap(SessionFactory.class).getStatistics();
+        stats.setStatisticsEnabled(true);
+        stats.clear();
+
+        documentRepository.findAll(PageRequest.of(0, 5, Sort.by(Sort.Direction.DESC, "updatedAt")));
+
+        assertThat(stats.getPrepareStatementCount())
+                .as("@EntityGraph(Document.list) via findAll(Pageable) must not N+1 sender for 5 docs")
+                .isLessThanOrEqualTo(5);
+    }
+
     // ─── seeding helpers ─────────────────────────────────────────────────────
 
     private Document uploaded(String title) {