JPA entity with @Entity annotation in Spring Boot - Mini Project: Build & Apply

JPA Entity with @Entity Annotation

📖 Scenario: You are building a simple Spring Boot application to manage a list of books in a library. Each book has an ID, a title, and an author.

🎯 Goal: Create a JPA entity class called Book using the @Entity annotation. This class will represent the books table in the database.

📋 What You'll Learn

Create a class named Book

Add the @Entity annotation to the Book class

Add a private field id of type Long annotated with @Id and @GeneratedValue

Add private fields title and author of type String

Add public getter and setter methods for all fields

💡 Why This Matters

🌍 Real World

JPA entities are used in real applications to represent database tables as Java classes. This helps developers work with databases using Java objects instead of SQL queries.

💼 Career

Understanding how to create JPA entities is essential for Java backend developers working with Spring Boot and relational databases.

1

Create the Book class

Create a public class named Book in a file called Book.java.

Spring Boot

// Your code here

Need a hint?

Start by defining a public class named Book.

2

Add the @Entity annotation

Add the @Entity annotation above the Book class declaration. Also import jakarta.persistence.Entity.

Spring Boot

@Entity
public class Book {
    // Your code here
}

Need a hint?

Use @Entity to tell Spring Boot this class is a database entity.

3

Add id, title, and author fields

Inside the Book class, add a private Long field named id annotated with @Id and @GeneratedValue. Also add private String fields named title and author. Import jakarta.persistence.Id and jakarta.persistence.GeneratedValue.

Spring Boot

import jakarta.persistence.Id;
import jakarta.persistence.GeneratedValue;

@Entity
public class Book {
    // Your code here
}

Need a hint?

Use @Id and @GeneratedValue to mark the primary key field.

4

Add getters and setters

Add public getter and setter methods for the id, title, and author fields inside the Book class.

Spring Boot

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.GeneratedValue;

@Entity
public class Book {
    @Id
    @GeneratedValue
    private Long id;
    private String title;
    private String author;

    // Your code here
}

Need a hint?

Write simple getter and setter methods for each field.