models, repos, test (#1225)

* models, repos, test

* update models and test

* updated test location

* update test location

spring-data-rest/src/main/java/com/baeldung/models/Book.java

@@ -0,0 +1,70 @@
+package com.baeldung.models;
+
+import java.util.List;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+
+@Entity
+public class Book {
+
+    @Id
+    @GeneratedValue
+    private long id;
+
+    @Column(nullable = false)
+    private String title;
+
+    @ManyToOne
+    @JoinColumn(name = "library_id")
+    private Library library;
+
+    @ManyToMany(mappedBy = "books")
+    private List<Author> authors;
+
+    public Book() {
+    }
+
+    public Book(String title) {
+        super();
+        this.title = title;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public Library getLibrary() {
+        return library;
+    }
+
+    public void setLibrary(Library library) {
+        this.library = library;
+    }
+
+    public List<Author> getAuthors() {
+        return authors;
+    }
+
+    public void setAuthors(List<Author> authors) {
+        this.authors = authors;
+    }
+
+}