Gp 128 migrate company products exercise COMPLETED

3-0-jpa-and-hibernate/3-1-2-company-products/src/main/java/com/bobocode/dao/CompanyDaoImpl.java

@@ -1,9 +1,13 @@
 package com.bobocode.dao;
 
+import com.bobocode.exception.CompanyDaoException;
 import com.bobocode.model.Company;
 import com.bobocode.util.ExerciseNotCompletedException;
+import org.hibernate.Session;
 
+import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
+import java.util.function.Function;
 
 public class CompanyDaoImpl implements CompanyDao {
     private EntityManagerFactory entityManagerFactory;
@@ -14,6 +18,27 @@ public CompanyDaoImpl(EntityManagerFactory entityManagerFactory) {
 
     @Override
     public Company findByIdFetchProducts(Long id) {
-        throw new ExerciseNotCompletedException(); // todo
+        return readWithinTx(entityManager ->
+                entityManager
+                        .createQuery("select c from Company c join fetch c.products where c.id = :id", Company.class)
+                        .setParameter("id", id)
+                        .getSingleResult()
+        );
+    }
+
+    private <T> T readWithinTx(Function<EntityManager, T> entityManagerFunction) {
+        EntityManager entityManager = entityManagerFactory.createEntityManager();
+        entityManager.unwrap(Session.class).setDefaultReadOnly(true);
+        entityManager.getTransaction().begin();
+        try {
+            T queryResult = entityManagerFunction.apply(entityManager);
+            entityManager.getTransaction().commit();
+            return queryResult;
+        } catch (Exception e) {
+            entityManager.getTransaction().rollback();
+            throw new CompanyDaoException("Error performing read operation", e);
+        } finally {
+            entityManager.close();
+        }
     }
 }

3-0-jpa-and-hibernate/3-1-2-company-products/src/main/java/com/bobocode/model/Company.java

@@ -1,10 +1,9 @@
 package com.bobocode.model;
 
 import com.bobocode.util.ExerciseNotCompletedException;
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
+import lombok.*;
 
+import javax.persistence.*;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -25,16 +24,28 @@
 @NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "company")
 public class Company {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String name;
+
+    @Setter(AccessLevel.PRIVATE)
+    @OneToMany(mappedBy = "company", fetch = FetchType.LAZY)
     private List<Product> products = new ArrayList<>();
 
     public void addProduct(Product product) {
-        throw new ExerciseNotCompletedException();
+        products.add(product);
+        product.setCompany(this);
     }
 
     public void removeProduct(Product product) {
-        throw new ExerciseNotCompletedException();
+        products.remove(product);
+        product.setCompany(null);
     }
 }

3-0-jpa-and-hibernate/3-1-2-company-products/src/main/java/com/bobocode/model/Product.java

@@ -1,9 +1,12 @@
 package com.bobocode.model;
 
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
+import javax.persistence.*;
+
 /**
  * todo:
  * - configure JPA entity
@@ -17,8 +20,18 @@
 @NoArgsConstructor
 @Getter
 @Setter
+@EqualsAndHashCode(of = "id")
+@Entity
+@Table(name = "product")
 public class Product {
+    @Id
+    @GeneratedValue
     private Long id;
+
+    @Column(nullable = false)
     private String name;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "company_id")
     private Company company;
 }