Gp 130 migrate photo comment dao exercise MAIN

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/README.MD

@@ -0,0 +1,25 @@
+# <img src="https://raw.githubusercontent.com/bobocode-projects/resources/master/image/logo_transparent_background.png" height=50/>Photo comment DAO exercise :muscle:
+Improve your *Hibernate ORM* and *JPA One-To-Many* relationship mapping skills
+### Task
+Each `Photo` has a list of `PhotoComments`. Comments cannot exits without photo associated. You job is to provide a mapping
+for this **bidirectional *one to many* relationship** and **implement required DAO methods.** Please follow the instructions 
+in the todo sections. 
+
+To verify your mapping, run `PhotoCommentMappingTest.java`
+To verify your DAO implementation, run `PhotoDaoTest.java`
+
+
+### Pre-conditions :heavy_exclamation_mark:
+You're supposed to be familiar with *JPA* mapping strategies and *Hibernate ORM*
+
+### How to start :question:
+* Just clone the repository and start implementing the **todo** section, verify your changes by running tests
+* If you don't have enough knowledge about this domain, check out the [links below](#related-materials-information_source)
+* Don't worry if you got stuck, checkout the **exercise/completed** branch and see the final implementation
+
+### Related materials :information_source:
+ * [JPA and Hibernate basics tutorial](https://github.com/boy4uck/jpa-hibernate-tutorial/tree/master/jpa-hibernate-basics) <img src="https://raw.githubusercontent.com/bobocode-projects/resources/master/image/logo_transparent_background.png" height=20/>
+ * [@OneToMany association](http://docs.jboss.org/hibernate/orm/5.3/userguide/html_single/Hibernate_User_Guide.html#associations-one-to-many)<img src="https://upload.wikimedia.org/wikipedia/commons/2/22/Hibernate_logo_a.png" height=15/>
+ * [The best way to map a @OneToMany relationship with JPA and Hibernate](https://vladmihalcea.com/the-best-way-to-map-a-onetomany-association-with-jpa-and-hibernate/)
+
+

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>3-0-jpa-and-hibernate</artifactId>
+        <groupId>com.bobocode</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>3-2-2-photo-comment-dao</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.bobocode</groupId>
+            <artifactId>jpa-hibernate-util</artifactId>
+            <version>1.0-SNAPSHOT</version>
+        </dependency>
+    </dependencies>
+
+</project>

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/src/main/java/com/bobocode/dao/PhotoDao.java

@@ -0,0 +1,49 @@
+package com.bobocode.dao;
+
+import com.bobocode.model.Photo;
+
+import java.util.List;
+
+/**
+ * {@link PhotoDao} defines and API of Data-Access Object for entity {@link Photo}
+ */
+public interface PhotoDao {
+
+    /**
+     * Saves photo into db and sets an id
+     *
+     * @param photo new photo
+     */
+    void save(Photo photo);
+
+    /**
+     * Retrieves a photo from the database by its id
+     *
+     * @param id photo id
+     * @return photo instance
+     */
+    Photo findById(long id);
+
+    /**
+     * Returns a list of all stored photos
+     *
+     * @return list of stored photos
+     */
+    List<Photo> findAll();
+
+    /**
+     * Removes a photo from the database
+     *
+     * @param photo an instance of stored photo
+     */
+    void remove(Photo photo);
+
+    /**
+     * Adds a new comment to an existing photo. This method does not require additional SQL select methods to load
+     * {@link Photo}.
+     *
+     * @param photoId
+     * @param comment
+     */
+    void addComment(long photoId, String comment);
+}

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/src/main/java/com/bobocode/dao/PhotoDaoImpl.java

@@ -0,0 +1,43 @@
+package com.bobocode.dao;
+
+import com.bobocode.model.Photo;
+import com.bobocode.util.ExerciseNotCompletedException;
+
+import javax.persistence.EntityManagerFactory;
+import java.util.List;
+
+/**
+ * Please note that you should not use auto-commit mode for your implementation.
+ */
+public class PhotoDaoImpl implements PhotoDao {
+    private EntityManagerFactory entityManagerFactory;
+
+    public PhotoDaoImpl(EntityManagerFactory entityManagerFactory) {
+        this.entityManagerFactory = entityManagerFactory;
+    }
+
+    @Override
+    public void save(Photo photo) {
+        throw new ExerciseNotCompletedException(); // todo
+    }
+
+    @Override
+    public Photo findById(long id) {
+        throw new ExerciseNotCompletedException(); // todo
+    }
+
+    @Override
+    public List<Photo> findAll() {
+        throw new ExerciseNotCompletedException(); // todo
+    }
+
+    @Override
+    public void remove(Photo photo) {
+        throw new ExerciseNotCompletedException(); // todo
+    }
+
+    @Override
+    public void addComment(long photoId, String comment) {
+        throw new ExerciseNotCompletedException(); // todo
+    }
+}

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/src/main/java/com/bobocode/model/Photo.java

@@ -0,0 +1,40 @@
+package com.bobocode.model;
+
+import com.bobocode.util.ExerciseNotCompletedException;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+
+/**
+ * todo:
+ * - make a setter for field {@link Photo#comments} {@code private}
+ * - implement equals() and hashCode() based on identifier field
+ *
+ * - configure JPA entity
+ * - specify table name: "photo"
+ * - configure auto generated identifier
+ * - configure not nullable and unique column: url
+ *
+ * - initialize field comments
+ * - map relation between Photo and PhotoComment on the child side
+ * - implement helper methods {@link Photo#addComment(PhotoComment)} and {@link Photo#removeComment(PhotoComment)}
+ * - enable cascade type {@link javax.persistence.CascadeType#ALL} for field {@link Photo#comments}
+ * - enable orphan removal
+ */
+@Getter
+@Setter
+public class Photo {
+    private Long id;
+    private String url;
+    private String description;
+    private List<PhotoComment> comments;
+
+    public void addComment(PhotoComment comment) {
+        throw new ExerciseNotCompletedException();
+    }
+
+    public void removeComment(PhotoComment comment) {
+        throw new ExerciseNotCompletedException();
+    }
+}

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/src/main/java/com/bobocode/model/PhotoComment.java

@@ -0,0 +1,27 @@
+package com.bobocode.model;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+/**
+ * todo:
+ * - implement equals and hashCode based on identifier field
+ *
+ * - configure JPA entity
+ * - specify table name: "photo_comment"
+ * - configure auto generated identifier
+ * - configure not nullable column: text
+ *
+ * - map relation between Photo and PhotoComment using foreign_key column: "photo_id"
+ * - configure relation as mandatory (not optional)
+ */
+@Getter
+@Setter
+public class PhotoComment {
+    private Long id;
+    private String text;
+    private LocalDateTime createdOn;
+    private Photo photo;
+}

3-0-jpa-and-hibernate/3-2-2-photo-comment-dao/src/main/resources/META-INF/persistence.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
+
+    <persistence-unit name="PhotoComments">
+        <class>com.bobocode.model.Photo</class>
+        <class>com.bobocode.model.PhotoComment</class>
+
+        <properties>
+            <property name="hibernate.connection.url" value="jdbc:h2:mem:movie_db;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false"/>
+            <property name="hibernate.connection.driver_class" value="org.h2.Driver"/>
+            <property name="hibernate.connection.username" value="movie_user"/>
+            <property name="hibernate.connection.password" value="movie_pass"/>
+            <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
+            <property name="hibernate.hbm2ddl.auto" value="create"/>
+            <property name="hibernate.show_sql" value="true"/>
+            <property name="hibernate.format_sql" value="true"/>
+        </properties>
+    </persistence-unit>
+
+</persistence>