Merge pull request #14 from gmbrax/feature/Implement-composer-management

Implement Composer Management with CRUD Operations

src/main/java/com/mediamanager/mapper/ArtistMapper.java

@@ -0,0 +1,41 @@
+package com.mediamanager.mapper;
+
+import com.mediamanager.model.Artist;
+import com.mediamanager.protocol.messages.ArtistMessages;
+
+
+public class ArtistMapper {
+    public static ArtistMessages.Artist toProtobuf(Artist entity){
+        if (entity == null) {
+            return null;
+        }
+
+        String name = entity.getName();
+        if (name == null) {
+            throw new IllegalArgumentException("Artist name cannot be null");
+        }
+
+        ArtistMessages.Artist.Builder builder = ArtistMessages.Artist.newBuilder()
+                .setName(name);
+
+        // Only set ID when it's present and valid (> 0). Avoids NPE for null IDs.
+        Integer id = entity.getId();
+        if (id != null && id > 0) {
+            builder.setId(id);
+        }
+
+        return builder.build();
+    }
+    public static Artist toEntity(ArtistMessages.Artist protobuf) {
+        if (protobuf == null) {
+            return null;
+        }
+        Artist entity = new Artist();
+
+        if (protobuf.getId() > 0) {
+            entity.setId(protobuf.getId());
+        }
+        entity.setName(protobuf.getName());
+        return entity;
+    }
+}

src/main/java/com/mediamanager/mapper/ComposerMapper.java

@@ -0,0 +1,38 @@
+package com.mediamanager.mapper;
+
+import com.mediamanager.model.Composer;
+import com.mediamanager.protocol.messages.ComposerMessages;
+
+public class ComposerMapper {
+    public static ComposerMessages.Composer toProtobuf(Composer entity) {
+        if (entity == null) {
+            return null;
+        }
+        ComposerMessages.Composer.Builder builder = ComposerMessages.Composer.newBuilder()
+                .setName(entity.getName());
+
+        Integer id = entity.getId();
+        if (id != null && id > 0) {
+            builder.setId(id);
+        }
+
+        return builder.build();
+
+    }
+
+    public static Composer toEntity(ComposerMessages.Composer protobuf) {
+        if (protobuf == null) {
+            return null;
+        }
+
+        Composer entity = new Composer();
+
+        if (protobuf.getId() > 0) {
+            entity.setId(protobuf.getId());
+        }
+
+        entity.setName(protobuf.getName());
+
+        return entity;
+    }
+}

src/main/java/com/mediamanager/model/Artist.java

@@ -0,0 +1,27 @@
+package com.mediamanager.model;
+
+import jakarta.persistence.*;
+
+@Entity
+@Table(name = "artist")
+public class Artist {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Integer id;
+
+    @Column(nullable = false)
+    private String name;
+
+    public Integer getId() {
+        return id;
+    }
+    public void setId(Integer id) {
+        this.id = id;
+    }
+    public String getName() {
+        return name;
+    }
+    public void setName(String name) {
+        this.name = name;
+    }
+}

src/main/java/com/mediamanager/model/Composer.java

@@ -0,0 +1,31 @@
+package com.mediamanager.model;
+
+
+import jakarta.persistence.*;
+
+@Entity
+@Table(name = "composer")
+public class Composer {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Integer id;
+
+    @Column(nullable = false)
+    private String name;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

src/main/java/com/mediamanager/repository/ArtistRepository.java

@@ -0,0 +1,104 @@
+package com.mediamanager.repository;
+import com.mediamanager.model.Artist;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+import java.util.Optional;
+
+public class ArtistRepository {
+    private static final Logger logger = LogManager.getLogger(ArtistRepository.class);
+
+    private final EntityManagerFactory entityManagerFactory;
+
+    public ArtistRepository(EntityManagerFactory entityManagerFactory) {
+        this.entityManagerFactory = entityManagerFactory;
+    }
+
+    public Artist save(Artist artist){
+        logger.debug("Saving Artist: {}", artist.getName());
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try {
+            em.persist(artist);
+            em.getTransaction().commit();
+            logger.debug("Artist saved with ID: {}", artist.getId());
+            return artist;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error saving Artist", e);
+            throw e;
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public List<Artist> findAll(){
+        logger.debug("Finding all Artists");
+        EntityManager em = entityManagerFactory.createEntityManager();
+        try {
+            return em
+                    .createQuery("SELECT a FROM Artist a ORDER BY a.name", Artist.class)
+                    .getResultList();
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public Optional<Artist> findById(Integer id){
+        logger.debug("Finding artist by ID: {}", id);
+        EntityManager em = entityManagerFactory.createEntityManager();
+        try {
+            Artist artist = em.find(Artist.class, id);
+            return Optional.ofNullable(artist);
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+
+    }
+
+    public Artist update(Artist artist){
+        logger.debug("Updating artist ID: {}", artist.getId());
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try {
+            Artist updated = em.merge(artist);
+            em.getTransaction().commit();
+            logger.debug("Artist updated successfully");
+            return updated;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error updating artist", e);
+            throw e;
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public boolean deleteById(Integer id){
+        logger.debug("Deleting Artist by ID: {}", id);
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try {
+            Artist artist = em.find(Artist.class, id);
+            if (artist == null) {
+                em.getTransaction().rollback();
+                return false;
+            }
+            em.remove(artist);
+            em.getTransaction().commit();
+            logger.debug("Artist deleted successfully");
+            return true;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error deleting artist", e);
+            throw e;
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+        }
+
+

src/main/java/com/mediamanager/repository/ComposerRepository.java

@@ -0,0 +1,102 @@
+package com.mediamanager.repository;
+
+import com.mediamanager.model.Composer;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+import java.util.Optional;
+
+public class ComposerRepository {
+    private static final Logger logger = LogManager.getLogger(ComposerRepository.class);
+
+    private final EntityManagerFactory entityManagerFactory;
+
+    public ComposerRepository(EntityManagerFactory entityManagerFactory) {
+        this.entityManagerFactory = entityManagerFactory;
+    }
+
+    public Composer save(Composer composer) {
+        logger.debug("Saving composer: {}", composer.getName());
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try{
+            //ToDo: Add Id Validation
+            //ToDo: Add to all Repositories
+            em.persist(composer);
+            em.getTransaction().commit();
+            logger.debug("Composer saved with IS: {}", composer.getId());
+            return composer;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error saving composer", e);
+            throw e;
+        }finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public List<Composer> findAll(){
+        logger.debug("Finding all composers");
+        EntityManager em = entityManagerFactory.createEntityManager();
+        try{
+            return em.createQuery("SELECT c FROM Composer c ORDER BY c.name", Composer.class).getResultList();
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public Optional<Composer> findById(Integer id){
+        logger.debug("Finding composer by ID: {}", id);
+        EntityManager em = entityManagerFactory.createEntityManager();
+        try{
+            Composer composer = em.find(Composer.class, id);
+            return Optional.ofNullable(composer);
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public Composer update(Composer composer){
+        logger.debug("Updating composer ID: {}", composer.getId());
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try{
+            Composer updated = em.merge(composer);
+            em.getTransaction().commit();
+            logger.debug("Composer updated successfully");
+            return updated;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error updating composer", e);
+            throw e;
+        } finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+
+    public boolean deleteById(Integer id){
+        logger.debug("Deleting composer by ID: {}", id);
+        EntityManager em = entityManagerFactory.createEntityManager();
+        em.getTransaction().begin();
+        try{
+           Composer composer = em.find(Composer.class, id);
+           if (composer == null) {
+               em.getTransaction().rollback();
+               return false;
+           }
+           em.remove(composer);
+           em.getTransaction().commit();
+           logger.debug("Composer deleted successfully");
+           return true;
+        } catch (Exception e) {
+            em.getTransaction().rollback();
+            logger.error("Error deleting composer", e);
+            throw e;
+        }finally {
+            if (em.isOpen()) em.close();
+        }
+    }
+}

src/main/java/com/mediamanager/service/artist/ArtistService.java

@@ -0,0 +1,65 @@
+package com.mediamanager.service.artist;
+
+import com.mediamanager.model.Artist;
+import com.mediamanager.repository.ArtistRepository;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+import java.util.Optional;
+
+public class ArtistService {
+    private static final Logger logger = LogManager.getLogger(ArtistService.class);
+    private final ArtistRepository artistRepository;
+
+    public ArtistService(ArtistRepository artistRepository) {
+        this.artistRepository = artistRepository;
+    }
+
+    public Artist createArtist(String name){
+        logger.info("Creating artist: {}", name);
+        if (name == null || name.trim().isEmpty()) {
+            throw new IllegalArgumentException("Artist name cannot be empty");
+        }
+        Artist artist = new Artist();
+        artist.setName(name.trim());
+        return artistRepository.save(artist);
+    }
+
+    public List<Artist> getAllArtists(){
+        logger.info("Getting all artists");
+        return artistRepository.findAll();
+    }
+
+    public Optional<Artist> getArtistById(Integer id){
+        logger.info("Getting artist by ID: {}", id);
+        return artistRepository.findById(id);
+    }
+
+    public Optional<Artist> updateArtist(Integer id, String name){
+        logger.info("Updating artist ID {}: {}", id, name);
+
+        if (name == null || name.trim().isEmpty()) {
+            throw new IllegalArgumentException("Artist name cannot be empty");
+        }
+
+        Optional<Artist> existingArtist = artistRepository.findById(id);
+
+        if(existingArtist.isEmpty()){
+            logger.warn("Artist not found with ID: {}", id);
+            return Optional.empty();
+        }
+        Artist artist = existingArtist.get();
+        artist.setName(name.trim());
+        Artist updatedArtist = artistRepository.update(artist);
+        return Optional.of(updatedArtist);
+    }
+
+    public boolean deleteArtist(Integer id){
+        logger.info("Deleting artist ID: {}", id);
+        return artistRepository.deleteById(id);
+    }
+
+
+
+}

src/main/java/com/mediamanager/service/composer/ComposerService.java

@@ -0,0 +1,70 @@
+package com.mediamanager.service.composer;
+
+import com.mediamanager.model.Composer;
+import com.mediamanager.repository.ComposerRepository;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+import java.util.Optional;
+
+public class ComposerService {
+    private static final Logger logger = LogManager.getLogger(ComposerService.class);
+
+    private final ComposerRepository composerRepository;
+
+    public ComposerService(ComposerRepository composerRepository) {
+        this.composerRepository = composerRepository;
+    }
+
+    public Composer createComposer(String name) {
+        logger.info("Creating composer: {}", name);
+        if(name == null || name.trim().isEmpty()) {
+            throw new IllegalArgumentException("Composer name cannot be empty");
+        }
+        Composer composer = new Composer();
+        composer.setName(name.trim());
+        return composerRepository.save(composer);
+
+
+    }
+
+    public List<Composer> getAllComposers() {
+        logger.info("Getting all composers");
+        return composerRepository.findAll();
+    }
+
+    public Optional<Composer> getComposerById(Integer id) {
+        logger.info("Getting composer by ID: {}", id);
+        return composerRepository.findById(id);
+    }
+
+    public Optional<Composer> updateComposer(Integer id, String name) {
+        logger.info("Updating composer ID {}: {}", id, name);
+
+        if(name == null || name.trim().isEmpty()) {
+            throw new IllegalArgumentException("Composer name cannot be empty");
+        }
+
+        Optional<Composer> existingComposer = composerRepository.findById(id);
+
+        if(existingComposer.isEmpty()) {
+            logger.warn("Composer not found with ID: {}", id);
+            return Optional.empty();
+        }
+
+        Composer composer = existingComposer.get();
+        composer.setName(name.trim());
+
+        Composer updated = composerRepository.update(composer);
+        return Optional.of(updated);
+
+    }
+
+    public boolean deleteComposer(Integer id) {
+        logger.info("Deleting composer ID: {}", id);
+        return composerRepository.deleteById(id);
+    }
+
+
+}

src/main/java/com/mediamanager/service/delegate/DelegateActionManager.java

@@ -2,7 +2,12 @@ package com.mediamanager.service.delegate;
 
 import com.google.protobuf.ByteString;
 import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.repository.ComposerRepository;
 import com.mediamanager.repository.GenreRepository;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.repository.ArtistRepository;
+import com.mediamanager.repository.GenreRepository;
+import com.mediamanager.service.artist.ArtistService;
 import com.mediamanager.service.delegate.annotation.Action;
 
 import com.mediamanager.service.genre.GenreService;
@@ -48,6 +53,19 @@ public class DelegateActionManager {
 
         serviceLocator.register(GenreService.class, genreService);
 
+        ArtistRepository artistRepository = new ArtistRepository(entityManagerFactory);
+        ArtistService artistService = new ArtistService(artistRepository);
+
+        serviceLocator.register(ArtistService.class, artistService);
+
+
+
+
+
+        ComposerRepository composerRepository = new ComposerRepository(entityManagerFactory);
+        ComposerService composerService = new ComposerService(composerRepository);
+        serviceLocator.register(ComposerService.class, composerService);
+
 
         serviceLocator.logRegisteredServices();
 

src/main/java/com/mediamanager/service/delegate/handler/artist/CreateArtistHandler.java

@@ -0,0 +1,50 @@
+package com.mediamanager.service.delegate.handler.artist;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ArtistMapper;
+import com.mediamanager.model.Artist;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ArtistMessages;
+import com.mediamanager.service.artist.ArtistService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Action("artist.create")
+public class CreateArtistHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(CreateArtistHandler.class);
+    private final ArtistService artistService;
+
+    public CreateArtistHandler(ArtistService artistService) {
+        this.artistService = artistService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload) throws InvalidProtocolBufferException {
+        try{
+            ArtistMessages.CreateArtistRequest createRequest =
+                    ArtistMessages.CreateArtistRequest.parseFrom(requestPayload);
+            Artist artist = artistService.createArtist(createRequest.getName());
+            ArtistMessages.Artist artistProto = ArtistMapper.toProtobuf(artist);
+            ArtistMessages.CreateArtistResponse createArtistResponse = ArtistMessages.CreateArtistResponse.newBuilder()
+                    .setArtist(artistProto)
+                    .build();
+            return TransportProtocol.Response.newBuilder()
+                    .setPayload(createArtistResponse.toByteString());
+        } catch (IllegalArgumentException e) {
+            logger.error("Validation error", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(400)
+                    .setPayload(ByteString.copyFromUtf8("Validation error: " + e.getMessage()));
+
+        } catch (Exception e) {
+            logger.error("Error creating artist", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+    }
+}
+

src/main/java/com/mediamanager/service/delegate/handler/artist/DeleteArtistHandler.java

@@ -0,0 +1,62 @@
+package com.mediamanager.service.delegate.handler.artist;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ArtistMessages;
+import com.mediamanager.service.artist.ArtistService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Action("artist.delete")
+public class DeleteArtistHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(DeleteArtistHandler.class);
+
+    private final ArtistService artistService;
+
+    public DeleteArtistHandler(ArtistService artistService) {
+        this.artistService = artistService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+
+        try {
+            ArtistMessages.DeleteArtistRequest deleteRequest =
+                    ArtistMessages.DeleteArtistRequest.parseFrom(requestPayload);
+            int id = deleteRequest.getId();
+            boolean success = artistService.deleteArtist(id);
+            ArtistMessages.DeleteArtistResponse deleteResponse;
+            if (success) {
+                deleteResponse = ArtistMessages.DeleteArtistResponse.newBuilder()
+                        .setSuccess(true)
+                        .setMessage("Artist deleted successfully")
+                        .build();
+                return TransportProtocol.Response.newBuilder()
+                        .setPayload(deleteResponse.toByteString());
+            } else {
+                deleteResponse = ArtistMessages.DeleteArtistResponse.newBuilder()
+                        .setSuccess(false)
+                        .setMessage("Artist not found")
+                        .build();
+
+                return TransportProtocol.Response.newBuilder()
+                        .setStatusCode(404)
+                        .setPayload(deleteResponse.toByteString());
+            }
+        } catch (Exception e) {
+            logger.error("Error deleting artist", e);
+            ArtistMessages.DeleteArtistResponse deleteResponse =
+                    ArtistMessages.DeleteArtistResponse.newBuilder()
+                            .setSuccess(false)
+                            .setMessage("Error: " + e.getMessage())
+                            .build();
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(deleteResponse.toByteString());
+        }
+    }
+    }

src/main/java/com/mediamanager/service/delegate/handler/artist/GetArtistByIdHandler.java

@@ -0,0 +1,56 @@
+package com.mediamanager.service.delegate.handler.artist;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ArtistMapper;
+import com.mediamanager.model.Artist;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ArtistMessages;
+import com.mediamanager.service.artist.ArtistService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Optional;
+
+@Action(value = "artist.getById")
+public class GetArtistByIdHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(GetArtistByIdHandler.class);
+    private final ArtistService artistService;
+
+    public GetArtistByIdHandler(ArtistService artistService) {
+        this.artistService = artistService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+        throws InvalidProtocolBufferException{
+
+        try{
+            ArtistMessages.GetArtistByIdRequest getByIdRequest =
+                    ArtistMessages.GetArtistByIdRequest.parseFrom(requestPayload);
+            int id = getByIdRequest.getId();
+
+            Optional<Artist> artistOpt = artistService.getArtistById(id);
+
+            if (artistOpt.isEmpty()){
+                logger.warn("Artist not found with ID: {}", id);
+                return TransportProtocol.Response.newBuilder()
+                        .setStatusCode(404)
+                        .setPayload(ByteString.copyFromUtf8("Artist not found"));
+            }
+            ArtistMessages.Artist artistProto = ArtistMapper.toProtobuf(artistOpt.get());
+            ArtistMessages.GetArtistByIdResponse getByIdResponse = ArtistMessages.GetArtistByIdResponse.newBuilder()
+                    .setArtist(artistProto)
+                    .build();
+            return TransportProtocol.Response.newBuilder()
+                    .setPayload(getByIdResponse.toByteString());
+        } catch (Exception e) {
+            logger.error("Error getting artist by ID", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: "+ e.getMessage()));
+        }
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/artist/GetArtistHandler.java

@@ -0,0 +1,48 @@
+package com.mediamanager.service.delegate.handler.artist;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ArtistMapper;
+import com.mediamanager.model.Artist;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ArtistMessages;
+import com.mediamanager.service.artist.ArtistService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+
+
+@Action("artist.getAll")
+public class GetArtistHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(GetArtistHandler.class);
+
+    private final ArtistService artistService;
+
+    public GetArtistHandler(ArtistService artistService){this.artistService = artistService;}
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload) throws InvalidProtocolBufferException {
+        try{
+            List<Artist> artists = artistService.getAllArtists();
+            ArtistMessages.GetArtistsResponse.Builder responseBuilder = ArtistMessages.GetArtistsResponse.newBuilder();
+
+            for (Artist artist : artists) {
+                ArtistMessages.Artist artistProto = ArtistMapper.toProtobuf(artist);
+                responseBuilder.addArtists(artistProto);
+            }
+            ArtistMessages.GetArtistsResponse getArtistsResponse = responseBuilder.build();
+
+            return TransportProtocol.Response.newBuilder()
+                    .setPayload(getArtistsResponse.toByteString());
+
+        }catch (Exception e){
+            logger.error("Error getting artists", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/artist/UpdateArtistHandler.java

@@ -0,0 +1,65 @@
+package com.mediamanager.service.delegate.handler.artist;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ArtistMapper;
+import com.mediamanager.model.Artist;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ArtistMessages;
+import com.mediamanager.service.artist.ArtistService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Optional;
+
+@Action("artist.update")
+public class UpdateArtistHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(UpdateArtistHandler.class);
+    private final ArtistService artistService;
+
+    public UpdateArtistHandler(ArtistService artistService) {
+        this.artistService = artistService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload) throws InvalidProtocolBufferException {
+        try{
+            ArtistMessages.UpdateArtistRequest updateRequest =
+                    ArtistMessages.UpdateArtistRequest.parseFrom(requestPayload);
+
+            int id = updateRequest.getId();
+            String newName = updateRequest.getName();
+
+            Optional<Artist> artistOpt = artistService.updateArtist(id, newName);
+
+            if(artistOpt.isEmpty()){
+                logger.warn("Artist not found with ID: {}", id);
+                return TransportProtocol.Response.newBuilder()
+                        .setStatusCode(404)
+                        .setPayload(ByteString.copyFromUtf8("Artist not found"));
+            }
+
+            ArtistMessages.Artist artistProto = ArtistMapper.toProtobuf(artistOpt.get());
+
+            ArtistMessages.UpdateArtistResponse updateResponse = ArtistMessages.UpdateArtistResponse.newBuilder()
+                    .setArtist(artistProto)
+                    .build();
+
+            return TransportProtocol.Response.newBuilder()
+                    .setPayload(updateResponse.toByteString());
+
+        } catch (IllegalArgumentException e){
+            logger.error("Validation error", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(400)
+                    .setPayload(ByteString.copyFromUtf8("Validation error: " + e.getMessage()));
+        } catch (Exception e) {
+            logger.error("Error updating artist", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/composer/CreateComposerHandler.java

@@ -0,0 +1,51 @@
+package com.mediamanager.service.delegate.handler.composer;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ComposerMapper;
+import com.mediamanager.model.Composer;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ComposerMessages;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Action("composer.create")
+public class CreateComposerHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(CreateComposerHandler.class);
+    private final ComposerService composerService;
+
+    public CreateComposerHandler(ComposerService composerService) {
+        this.composerService = composerService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+        try{
+            ComposerMessages.CreateComposerRequest CreateRequest = ComposerMessages.CreateComposerRequest
+                    .parseFrom(requestPayload);
+            Composer composer = composerService.createComposer(CreateRequest.getName());
+            ComposerMessages.Composer composerProto = ComposerMapper.toProtobuf(composer);
+            ComposerMessages.CreateComposerResponse createResponse = ComposerMessages.CreateComposerResponse
+                    .newBuilder().setComposer(composerProto).build();
+            return TransportProtocol.Response.newBuilder().setPayload(createResponse.toByteString());
+
+        } catch (IllegalArgumentException e){
+            logger.error("Validation error", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(400)
+                    .setPayload(ByteString.copyFromUtf8("Validation error: " + e.getMessage()));
+
+        } catch (Exception e){
+            logger.error("Error creating composer", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/composer/DeleteComposerHandler.java

@@ -0,0 +1,53 @@
+package com.mediamanager.service.delegate.handler.composer;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ComposerMessages;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Action( "composer.delete")
+public class DeleteComposerHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(DeleteComposerHandler.class);
+    private final ComposerService composerService;
+
+
+    public DeleteComposerHandler(ComposerService composerService){
+        this.composerService = composerService;
+    }
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+        try {
+            ComposerMessages.DeleteComposerRequest deleteRequest =
+                    ComposerMessages.DeleteComposerRequest.parseFrom(requestPayload);
+            int id = deleteRequest.getId();
+            boolean success = composerService.deleteComposer(id);
+            ComposerMessages.DeleteComposerResponse deleteResponse;
+            if(success){
+                deleteResponse = ComposerMessages.DeleteComposerResponse.newBuilder().setSuccess(true)
+                        .setMessage("Composer deleted successfully").build();
+
+
+                return TransportProtocol.Response.newBuilder()
+                        .setPayload(deleteResponse.toByteString());
+            }else {
+                deleteResponse = ComposerMessages.DeleteComposerResponse.newBuilder().setSuccess(false)
+                        .setMessage("Composer not found").build();
+                return TransportProtocol.Response.newBuilder().setStatusCode(404)
+                        .setPayload(deleteResponse.toByteString());
+            }
+
+        } catch (Exception e) {
+            logger.error("Error deleting composer", e);
+            ComposerMessages.DeleteComposerResponse deleteResponse = ComposerMessages.DeleteComposerResponse
+                    .newBuilder().setSuccess(false).setMessage("Error: " + e.getMessage()).build();
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500).setPayload(deleteResponse.toByteString());
+        }
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/composer/GetComposerByIdHandler.java

@@ -0,0 +1,57 @@
+package com.mediamanager.service.delegate.handler.composer;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ComposerMapper;
+import com.mediamanager.model.Composer;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ComposerMessages;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Optional;
+
+@Action( "composer.getById")
+public class GetComposerByIdHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(GetComposerByIdHandler.class);
+    private final ComposerService composerService;
+
+    public GetComposerByIdHandler(ComposerService composerService){
+        this.composerService = composerService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+        try{
+
+            ComposerMessages.GetComposerByIdRequest getByIdRequest = ComposerMessages.GetComposerByIdRequest
+                    .parseFrom(requestPayload);
+            int id = getByIdRequest.getId();
+
+            Optional<Composer> composerOpt = composerService.getComposerById(id);
+
+            if (composerOpt.isEmpty()) {
+              logger.warn("Composer not found with ID: {}", id);
+              return TransportProtocol.Response.newBuilder()
+                      .setStatusCode(404)
+                      .setPayload(ByteString.copyFromUtf8("Composer not found"));
+            }
+
+            ComposerMessages.Composer composerProto = ComposerMapper.toProtobuf(composerOpt.get());
+
+            ComposerMessages.GetComposerByIdResponse getByIdResponse = ComposerMessages.GetComposerByIdResponse
+                    .newBuilder().setComposer(composerProto).build();
+
+            return TransportProtocol.Response.newBuilder().setPayload(getByIdResponse.toByteString());
+        } catch (Exception e) {
+            logger.error("Error getting composer by ID", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+    }
+}

src/main/java/com/mediamanager/service/delegate/handler/composer/GetComposerHandler.java

@@ -0,0 +1,50 @@
+package com.mediamanager.service.delegate.handler.composer;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ComposerMapper;
+import com.mediamanager.model.Composer;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ComposerMessages;
+import com.mediamanager.protocol.messages.GenreMessages;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.List;
+
+@Action( "composer.getAll")
+public class GetComposerHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(GetComposerHandler.class);
+    private final ComposerService composerService;
+
+    public GetComposerHandler(ComposerService composerService){
+        this.composerService = composerService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+
+        try{
+            List<Composer> composers = composerService.getAllComposers();
+
+            ComposerMessages.GetComposersResponse.Builder responseBuilder = ComposerMessages.GetComposersResponse.newBuilder();
+            for(Composer composer : composers){
+                ComposerMessages.Composer composerProto = ComposerMapper.toProtobuf(composer);
+                responseBuilder.addComposers(composerProto);
+            }
+            ComposerMessages.GetComposersResponse getGenresResponse = responseBuilder.build();
+            return TransportProtocol.Response.newBuilder().setPayload(getGenresResponse.toByteString());
+        } catch (Exception e) {
+            logger.error("Error getting composers", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+
+    }
+
+}

src/main/java/com/mediamanager/service/delegate/handler/composer/UpdateComposerHandler.java

@@ -0,0 +1,56 @@
+package com.mediamanager.service.delegate.handler.composer;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.mediamanager.mapper.ComposerMapper;
+import com.mediamanager.model.Composer;
+import com.mediamanager.protocol.TransportProtocol;
+import com.mediamanager.protocol.messages.ComposerMessages;
+import com.mediamanager.service.composer.ComposerService;
+import com.mediamanager.service.delegate.ActionHandler;
+import com.mediamanager.service.delegate.annotation.Action;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Optional;
+
+@Action("composer.update")
+public class UpdateComposerHandler implements ActionHandler {
+    private static final Logger logger = LogManager.getLogger(UpdateComposerHandler.class);
+    private final ComposerService composerService;
+    public UpdateComposerHandler(ComposerService composerService){
+        this.composerService = composerService;
+    }
+
+    @Override
+    public TransportProtocol.Response.Builder handle(ByteString requestPayload)
+            throws InvalidProtocolBufferException {
+        try{
+            ComposerMessages.UpdateComposerRequest updateRequest = ComposerMessages.UpdateComposerRequest
+                    .parseFrom(requestPayload);
+            int id = updateRequest.getId();
+            String newName = updateRequest.getName();
+            Optional<Composer> composerOpt = composerService.updateComposer(id, newName);
+            if (composerOpt.isEmpty()) {
+                logger.warn("Composer not found with ID: {}", id);
+                return TransportProtocol.Response.newBuilder()
+                        .setStatusCode(404)
+                        .setPayload(ByteString.copyFromUtf8("Composer not found"));
+            }
+            ComposerMessages.Composer composerProto = ComposerMapper.toProtobuf(composerOpt.get());
+            ComposerMessages.UpdateComposerResponse updateResponse = ComposerMessages.UpdateComposerResponse
+                    .newBuilder().setComposer(composerProto).build();
+            return TransportProtocol.Response.newBuilder().setPayload(updateResponse.toByteString());
+        }catch (IllegalArgumentException e){
+            logger.error("Validation error", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(400)
+                    .setPayload(ByteString.copyFromUtf8("Validation error: " + e.getMessage()));
+        } catch (Exception e) {
+            logger.error("Error updating composer", e);
+            return TransportProtocol.Response.newBuilder()
+                    .setStatusCode(500)
+                    .setPayload(ByteString.copyFromUtf8("Error: " + e.getMessage()));
+        }
+    }
+}

src/main/proto/artist.proto

@@ -0,0 +1,53 @@
+syntax = "proto3";
+
+option java_package = "com.mediamanager.protocol.messages";
+option java_outer_classname = "ArtistMessages";
+
+package mediamanager.messages;
+
+message Artist {
+  int32 id = 1;
+  string name = 2;
+}
+
+message CreateArtistRequest {
+  string name = 1;
+}
+
+message CreateArtistResponse {
+  Artist artist = 1;
+}
+
+message GetArtistsRequest {
+
+}
+
+message GetArtistsResponse {
+  repeated Artist artists = 1;
+}
+
+message GetArtistByIdRequest {
+  int32 id = 1;
+}
+
+message GetArtistByIdResponse {
+  Artist artist = 1;
+}
+
+message UpdateArtistRequest {
+  int32 id = 1;
+  string name = 2;  // Novo nome
+}
+
+message UpdateArtistResponse {
+  Artist Artist = 1;
+}
+
+message DeleteArtistRequest {
+  int32 id = 1;
+}
+
+message DeleteArtistResponse {
+  bool success = 1;
+  string message = 2;
+}

src/main/proto/composer.proto

@@ -0,0 +1,51 @@
+syntax = "proto3";
+
+option java_package = "com.mediamanager.protocol.messages";
+option java_outer_classname = "ComposerMessages";
+
+package mediamanager.messages;
+
+message Composer {
+  int32 id =1;
+  string name =2;
+}
+
+message CreateComposerRequest{
+  string name =1;
+}
+
+message CreateComposerResponse{
+  Composer composer = 1;
+}
+
+message GetComposersRequest{}
+
+message GetComposersResponse{
+  repeated Composer composers = 1;
+}
+
+message GetComposerByIdRequest{
+  int32 id =1;
+}
+
+message GetComposerByIdResponse{
+  Composer composer =1;
+}
+
+message UpdateComposerRequest{
+  int32 id = 1;
+  string name=2;
+}
+
+message UpdateComposerResponse{
+  Composer composer = 1;
+}
+
+message DeleteComposerRequest{
+  int32 id = 1;
+}
+
+message DeleteComposerResponse{
+  bool success = 1;
+  string message = 2;
+}