@SpringBootTest for integration tests - Mini Project: Build & Apply

Using @SpringBootTest for Integration Tests

📖 Scenario: You are building a simple Spring Boot application that manages a list of books. You want to write integration tests to check that your application context loads correctly and that your service works as expected.

🎯 Goal: Create a Spring Boot integration test class using @SpringBootTest to load the full application context and test a simple service method.

📋 What You'll Learn

Create a Spring Boot test class annotated with @SpringBootTest

Inject the BookService bean into the test class

Write a test method that calls getAllBooks() from BookService

Use assertions to verify the returned list is not null and contains expected data

💡 Why This Matters

🌍 Real World

Integration tests ensure that Spring Boot components work together correctly, catching issues early before deployment.

💼 Career

Spring Boot integration testing is a common task for backend developers to verify application behavior in a real environment.

1

Create the BookService class

Create a Spring service class called BookService with a method getAllBooks() that returns a list containing exactly these two strings: "Spring Boot Guide" and "Learning Java".

Spring Boot

# Create the BookService class with getAllBooks() method
# Your code here

Need a hint?

Use @Service annotation and return a list with List.of().

2

Create the test class with @SpringBootTest

Create a test class called BookServiceIntegrationTest annotated with @SpringBootTest. Inside it, declare a private field bookService of type BookService and annotate it with @Autowired.

Spring Boot

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.junit.jupiter.api.Test;

@SpringBootTest
public class BookServiceIntegrationTest {
    // Declare bookService here
    // Your code here
}

Need a hint?

Use @SpringBootTest on the class and @Autowired on the service field.

3

Write a test method to call getAllBooks()

Inside BookServiceIntegrationTest, write a test method called testGetAllBooks() annotated with @Test. In this method, call bookService.getAllBooks() and store the result in a variable called books.

Spring Boot

import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class BookService {
    public List getAllBooks() {
        return List.of("Spring Boot Guide", "Learning Java");
    }
}

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.junit.jupiter.api.Test;

@SpringBootTest
public class BookServiceIntegrationTest {
    @Autowired
    private BookService bookService;

    @Test
    // Call getAllBooks() and store in books
    // Your code here
}

Need a hint?

Use @Test annotation and call the service method inside the test.

4

Add assertions to verify the books list

In the testGetAllBooks() method, add assertions using org.junit.jupiter.api.Assertions to check that books is not null and that it contains exactly two items: "Spring Boot Guide" and "Learning Java".

Spring Boot

import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class BookService {
    public List getAllBooks() {
        return List.of("Spring Boot Guide", "Learning Java");
    }
}

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.junit.jupiter.api.Test;
import java.util.List;
import static org.junit.jupiter.api.Assertions.*;

@SpringBootTest
public class BookServiceIntegrationTest {
    @Autowired
    private BookService bookService;

    @Test
    public void testGetAllBooks() {
        List books = bookService.getAllBooks();
        // Add assertions here
        // Your code here
    }
}

Need a hint?

Use assertNotNull, assertEquals, and assertTrue to check the list contents.