Finalize the repository layer

Author: Chamal-Peiris

src/main/java/lk/ijse/dep/notes/repository/CrudRepository.java

@@ -10,7 +10,7 @@
 
 public interface CrudRepository<T extends SuperEntity,ID extends Serializable> extends SuperRepository {
 
-    ID save(T entity);
+    T save(T entity);
     void deleteById(ID pk);
     boolean existById(ID pk);
     Optional<T>findById(ID pk);

src/main/java/lk/ijse/dep/notes/repository/CrudRepositoryImpl.java

@@ -0,0 +1,53 @@
+package lk.ijse.dep.notes.repository;
+
+import lk.ijse.dep.notes.entity.SuperEntity;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.io.Serializable;
+import java.lang.reflect.ParameterizedType;
+import java.util.List;
+import java.util.Optional;
+
+public abstract class CrudRepositoryImpl <T extends SuperEntity,ID extends Serializable> implements CrudRepository<T,ID>{
+
+    @PersistenceContext
+    protected EntityManager entityManager;
+
+    private  Class<T> entityClzObj;
+
+    public CrudRepositoryImpl(){
+       this.entityClzObj= (Class<T>) ((ParameterizedType)this.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
+    }
+    @Override
+    public T save(T entity) {
+       return entityManager.merge(entity);
+
+    }
+
+    @Override
+    public void deleteById(ID pk) {
+
+        entityManager.remove(entityManager.getReference(entityClzObj,pk));
+    }
+
+    @Override
+    public boolean existById(ID pk) {
+      return findById(pk).isPresent();
+    }
+
+    @Override
+    public Optional<T> findById(ID pk) {
+       return Optional.of( entityManager.find(entityClzObj,pk));
+    }
+
+    @Override
+    public List<T> findAll() {
+       return entityManager.createQuery("SELECT e FROM "+entityClzObj.getName()+" e",entityClzObj).getResultList();
+    }
+
+    @Override
+    public long count() {
+        return entityManager.createQuery("SELECT COUNT(e) FROM "+entityClzObj.getName()+" e",Long.class).getSingleResult();
+    }
+}

src/main/java/lk/ijse/dep/notes/repository/custom/NoteRepository.java

@@ -0,0 +1,7 @@
+package lk.ijse.dep.notes.repository.custom;
+
+import lk.ijse.dep.notes.entity.Note;
+import lk.ijse.dep.notes.repository.CrudRepository;
+
+public interface NoteRepository extends CrudRepository<Note,Integer> {
+}

src/main/java/lk/ijse/dep/notes/repository/custom/QueryRepository.java

@@ -0,0 +1,7 @@
+package lk.ijse.dep.notes.repository.custom;
+
+import lk.ijse.dep.notes.repository.CrudRepository;
+import lk.ijse.dep.notes.repository.SuperRepository;
+
+public interface QueryRepository extends SuperRepository {
+}

src/main/java/lk/ijse/dep/notes/repository/custom/UserRepository.java

@@ -0,0 +1,7 @@
+package lk.ijse.dep.notes.repository.custom;
+
+import lk.ijse.dep.notes.entity.User;
+import lk.ijse.dep.notes.repository.CrudRepository;
+
+public interface UserRepository extends CrudRepository<User,String> {
+}

src/main/java/lk/ijse/dep/notes/repository/custom/impl/NoteRepositoryImpl.java

@@ -0,0 +1,9 @@
+package lk.ijse.dep.notes.repository.custom.impl;
+
+import lk.ijse.dep.notes.entity.Note;
+import lk.ijse.dep.notes.repository.CrudRepositoryImpl;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class NoteRepositoryImpl extends CrudRepositoryImpl<Note,String> {
+}

src/main/java/lk/ijse/dep/notes/repository/custom/impl/QueryRepositoryImpl.java

@@ -0,0 +1,11 @@
+package lk.ijse.dep.notes.repository.custom.impl;
+
+import lk.ijse.dep.notes.repository.custom.QueryRepository;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+
+public class QueryRepositoryImpl implements QueryRepository {
+    @PersistenceContext
+    private EntityManager em;
+}

src/main/java/lk/ijse/dep/notes/repository/custom/impl/UserRepositoryImpl.java

@@ -0,0 +1,9 @@
+package lk.ijse.dep.notes.repository.custom.impl;
+
+import lk.ijse.dep.notes.entity.User;
+import lk.ijse.dep.notes.repository.CrudRepositoryImpl;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class UserRepositoryImpl extends CrudRepositoryImpl<User,String> {
+}