Mongodb morphia (#7316)

* Adding source code for tutorial tracked by BAEL-2971

* Renaming Integration Test as par standard

* Incorporated review comments on the article.

* Moved the morphia module inside persistence-modules/java-mongodb

* Deleted the module morphia.

persistence-modules/java-mongodb/src/main/java/com/baeldung/morphia/domain/Author.java

@@ -0,0 +1,31 @@
+package com.baeldung.morphia.domain;
+
+import java.util.List;
+
+import dev.morphia.annotations.Entity;
+import dev.morphia.annotations.Id;
+
+@Entity
+public class Author {
+
+    @Id
+    private String name;
+    private List<String> books;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public List<String> getBooks() {
+        return books;
+    }
+
+    public void setBooks(List<String> books) {
+        this.books = books;
+    }
+
+}

persistence-modules/java-mongodb/src/main/java/com/baeldung/morphia/domain/Book.java

@@ -0,0 +1,116 @@
+package com.baeldung.morphia.domain;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import dev.morphia.annotations.Embedded;
+import dev.morphia.annotations.Entity;
+import dev.morphia.annotations.Field;
+import dev.morphia.annotations.Id;
+import dev.morphia.annotations.Index;
+import dev.morphia.annotations.IndexOptions;
+import dev.morphia.annotations.Indexes;
+import dev.morphia.annotations.Property;
+import dev.morphia.annotations.Reference;
+import dev.morphia.annotations.Validation;
+
+@Entity("Books")
+@Indexes({ @Index(fields = @Field("title"), options = @IndexOptions(name = "book_title")) })
+@Validation("{ price : { $gt : 0 } }")
+public class Book {
+    @Id
+    private String isbn;
+    @Property
+    private String title;
+    private String author;
+    @Embedded
+    private Publisher publisher;
+    @Property("price")
+    private double cost;
+    @Reference
+    private Set<Book> companionBooks;
+
+    public Book() {
+
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public double getCost() {
+        return cost;
+    }
+
+    public void addCompanionBooks(Book book) {
+        if (companionBooks != null)
+            this.companionBooks.add(book);
+    }
+
+    public Book(String isbn, String title, String author, double cost, Publisher publisher) {
+        this.isbn = isbn;
+        this.title = title;
+        this.author = author;
+        this.cost = cost;
+        this.publisher = publisher;
+        this.companionBooks = new HashSet<>();
+    }
+
+    @Override
+    public String toString() {
+        return "Book [isbn=" + isbn + ", title=" + title + ", author=" + author + ", publisher=" + publisher + ", cost=" + cost + "]";
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((author == null) ? 0 : author.hashCode());
+        long temp;
+        temp = Double.doubleToLongBits(cost);
+        result = prime * result + (int) (temp ^ (temp >>> 32));
+        result = prime * result + ((isbn == null) ? 0 : isbn.hashCode());
+        result = prime * result + ((publisher == null) ? 0 : publisher.hashCode());
+        result = prime * result + ((title == null) ? 0 : title.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Book other = (Book) obj;
+        if (author == null) {
+            if (other.author != null)
+                return false;
+        } else if (!author.equals(other.author))
+            return false;
+        if (Double.doubleToLongBits(cost) != Double.doubleToLongBits(other.cost))
+            return false;
+        if (isbn == null) {
+            if (other.isbn != null)
+                return false;
+        } else if (!isbn.equals(other.isbn))
+            return false;
+        if (publisher == null) {
+            if (other.publisher != null)
+                return false;
+        } else if (!publisher.equals(other.publisher))
+            return false;
+        if (title == null) {
+            if (other.title != null)
+                return false;
+        } else if (!title.equals(other.title))
+            return false;
+        return true;
+    }
+
+}

persistence-modules/java-mongodb/src/main/java/com/baeldung/morphia/domain/Publisher.java

@@ -0,0 +1,70 @@
+package com.baeldung.morphia.domain;
+
+import org.bson.types.ObjectId;
+
+import dev.morphia.annotations.Entity;
+import dev.morphia.annotations.Id;
+
+@Entity
+public class Publisher {
+
+    @Id
+    private ObjectId id;
+    private String name;
+
+    public Publisher() {
+
+    }
+
+    public Publisher(ObjectId id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public ObjectId getId() {
+        return id;
+    }
+
+    public void setId(ObjectId id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return "Catalog [id=" + id + ", name=" + name + "]";
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Publisher other = (Publisher) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+}