Java E-commerce Tutorial: Getting Started393

In this tutorial, we will build a simple e-commerce application using Java. We will use Spring Boot as the framework and Hibernate as the ORM. We will also use MySQL as the database.

Prerequisites

Before you start, make sure you have the following installed:
Java 8 or later
Maven
MySQL

Creating a new Spring Boot project

Let's start by creating a new Spring Boot project. Open your terminal and run the following command:```
mvn archetype:generate -DgroupId= -DartifactId=e-commerce -Dversion=0.0.1-SNAPSHOT -DarchetypeGroupId= -DarchetypeArtifactId=spring-boot-starter-parent
```

This will create a new directory called `e-commerce`. Navigate to this directory and open the `` file.

Add the following dependency to the `` file:```xml

spring-boot-starter-data-jpa

```

This dependency will add support for JPA to our project.

Creating the database

Next, we need to create the database. Open your MySQL command line and run the following commands:```
CREATE DATABASE e-commerce;
USE e-commerce;
CREATE TABLE products (
id INT NOT NULL AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
price DECIMAL(10,2) NOT NULL,
PRIMARY KEY (id)
);
```

This will create a new database called `e-commerce` and a table called `products`.

Creating the entities

Now, we need to create the entities. Entities are classes that represent our data model. We will create two entities: `Product` and `Order`.

Create a new file called `` in the `src/main/java/com/example/e-commerce/model` package.```java
@Entity
public class Product {
@Id
@GeneratedValue(strategy = )
private Integer id;
private String name;
private BigDecimal price;
// Getters and setters
}
```

Create a new file called `` in the `src/main/java/com/example/e-commerce/model` package.```java
@Entity
public class Order {
@Id
@GeneratedValue(strategy = )
private Integer id;
private String customerName;
private Date orderDate;
private BigDecimal totalAmount;
// Getters and setters
}
```

Creating the repository

Next, we need to create the repository. Repositories are interfaces that provide CRUD operations for our entities.

Create a new file called `` in the `src/main/java/com/example/e-commerce/repository` package.```java
public interface ProductRepository extends JpaRepository {
}
```

Create a new file called `` in the `src/main/java/com/example/e-commerce/repository` package.```java
public interface OrderRepository extends JpaRepository {
}
```

Creating the service

Next, we need to create the service. Services are classes that contain the business logic of our application.

Create a new file called `` in the `src/main/java/com/example/e-commerce/service` package.```java
@Service
public class ProductService {
@Autowired
private ProductRepository productRepository;
public List getAllProducts() {
return ();
}
public Product getProductById(Integer id) {
return (id).orElseThrow(() -> new ResourceNotFoundException("Product not found"));
}
public Product createProduct(Product product) {
return (product);
}
public Product updateProduct(Integer id, Product product) {
Product existingProduct = (id).orElseThrow(() -> new ResourceNotFoundException("Product not found"));
(());
(());
return (existingProduct);
}
public void deleteProduct(Integer id) {
(id);
}
}
```

Create a new file called `` in the `src/main/java/com/example/e-commerce/service` package.```java
@Service
public class OrderService {
@Autowired
private OrderRepository orderRepository;
public List getAllOrders() {
return ();
}
public Order getOrderById(Integer id) {
return (id).orElseThrow(() -> new ResourceNotFoundException("Order not found"));
}
public Order createOrder(Order order) {
return (order);
}
public Order updateOrder(Integer id, Order order) {
Order existingOrder = (id).orElseThrow(() -> new ResourceNotFoundException("Order not found"));
(());
(());
(());
return (existingOrder);
}
public void deleteOrder(Integer id) {
(id);
}
}
```

Creating the controller

Finally, we need to create the controller. Controllers are classes that handle HTTP requests.

Create a new file called `` in the `src/main/java/com/example/e-commerce/controller` package.```java
@RestController
@RequestMapping("/api/products")
public class ProductController {
@Autowired
private ProductService productService;
@GetMapping
public List getAllProducts() {
return ();
}
@GetMapping("/{id}")
public Product getProductById(@PathVariable Integer id) {
return (id);
}
@PostMapping
public Product createProduct(@RequestBody Product product) {
return (product);
}
@PutMapping("/{id}")
public Product updateProduct(@PathVariable Integer id, @RequestBody Product product) {
return (id, product);
}
@DeleteMapping("/{id}")
public void deleteProduct(@PathVariable Integer id) {
(id);
}
}
```

Create a new file called `` in the `src/main/java/com/example/e-commerce/controller` package.```java
@RestController
@RequestMapping("/api/orders")
public class OrderController {
@Autowired
private OrderService orderService;
@GetMapping
public List getAllOrders() {
return ();
}
@GetMapping("/{id}")
public Order getOrderById(@PathVariable Integer id) {
return (id);
}
@PostMapping
public Order createOrder(@RequestBody Order order) {
return (order);
}
@PutMapping("/{id}")
public Order updateOrder(@PathVariable Integer id, @RequestBody Order order) {
return (id, order);
}
@DeleteMapping("/{id}")
public void deleteOrder(@PathVariable Integer id) {
(id);
}
}
```