Testcontainers container lifecycle management using JUnit 5

In this guide, you will learn how to:

• Start and stop containers using JUnit 5 lifecycle callbacks
• Manage containers using JUnit 5 extension annotations (@Testcontainers and @Container)
• Share containers across multiple test classes using the singleton containers pattern
• Avoid a common misconfiguration when combining extension annotations with singleton containers

Prerequisites

• Java 17+
• Your preferred IDE
• A Docker environment supported by Testcontainers

[!NOTE] If you're new to Testcontainers, visit the Testcontainers overview to learn more about Testcontainers and the benefits of using it.

Create the project and business logic

Set up the project

Create a Java project with Maven and add the required dependencies:

<dependencies>
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>42.7.3</version>
    </dependency>
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.5.6</version>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter</artifactId>
        <version>5.10.2</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.testcontainers</groupId>
        <artifactId>testcontainers-junit-jupiter</artifactId>
        <version>2.0.4</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.testcontainers</groupId>
        <artifactId>testcontainers-postgresql</artifactId>
        <version>2.0.4</version>
        <scope>test</scope>
    </dependency>
</dependencies>

Create the business logic

Create a Customer record:

package com.testcontainers.demo;

public record Customer(Long id, String name) {}

Create a CustomerService class with methods to create, retrieve, and delete customers:

package com.testcontainers.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

public class CustomerService {

  private final String url;
  private final String username;
  private final String password;

  public CustomerService(String url, String username, String password) {
    this.url = url;
    this.username = username;
    this.password = password;
    createCustomersTableIfNotExists();
  }

  public void createCustomer(Customer customer) {
    try (Connection conn = this.getConnection()) {
      PreparedStatement pstmt = conn.prepareStatement(
        "insert into customers(id,name) values(?,?)"
      );
      pstmt.setLong(1, customer.id());
      pstmt.setString(2, customer.name());
      pstmt.execute();
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }

  public List<Customer> getAllCustomers() {
    List<Customer> customers = new ArrayList<>();
    try (Connection conn = this.getConnection()) {
      PreparedStatement pstmt = conn.prepareStatement(
        "select id,name from customers"
      );
      ResultSet rs = pstmt.executeQuery();
      while (rs.next()) {
        long id = rs.getLong("id");
        String name = rs.getString("name");
        customers.add(new Customer(id, name));
      }
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
    return customers;
  }

  public Optional<Customer> getCustomer(Long customerId) {
    try (Connection conn = this.getConnection()) {
      PreparedStatement pstmt = conn.prepareStatement(
        "select id,name from customers where id = ?"
      );
      pstmt.setLong(1, customerId);
      ResultSet rs = pstmt.executeQuery();
      if (rs.next()) {
        long id = rs.getLong("id");
        String name = rs.getString("name");
        return Optional.of(new Customer(id, name));
      }
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
    return Optional.empty();
  }

  public void deleteAllCustomers() {
    try (Connection conn = this.getConnection()) {
      PreparedStatement pstmt = conn.prepareStatement("delete from customers");
      pstmt.execute();
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }

  private void createCustomersTableIfNotExists() {
    try (Connection conn = this.getConnection()) {
      PreparedStatement pstmt = conn.prepareStatement(
        """
        create table if not exists customers (
            id bigint not null,
            name varchar not null,
            primary key (id)
        )
        """
      );
      pstmt.execute();
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }

  private Connection getConnection() {
    try {
      return DriverManager.getConnection(url, username, password);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
}

JUnit 5 lifecycle callbacks

When testing with Testcontainers, you want to start the required containers before executing any tests and remove them afterwards. You can use JUnit 5 @BeforeAll and @AfterAll lifecycle callback methods for this:

package com.testcontainers.demo;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.List;
import java.util.Optional;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.testcontainers.postgresql.PostgreSQLContainer;

class CustomerServiceWithLifeCycleCallbacksTest {

  static PostgreSQLContainer postgres = new PostgreSQLContainer(
    "postgres:16-alpine"
  );

  CustomerService customerService;

  @BeforeAll
  static void startContainers() {
    postgres.start();
  }

  @AfterAll
  static void stopContainers() {
    postgres.stop();
  }

  @BeforeEach
  void setUp() {
    customerService =
    new CustomerService(
      postgres.getJdbcUrl(),
      postgres.getUsername(),
      postgres.getPassword()
    );
    customerService.deleteAllCustomers();
  }

  @Test
  void shouldCreateCustomer() {
    customerService.createCustomer(new Customer(1L, "George"));

    Optional<Customer> customer = customerService.getCustomer(1L);
    assertTrue(customer.isPresent());
    assertEquals(1L, customer.get().id());
    assertEquals("George", customer.get().name());
  }

  @Test
  void shouldGetCustomers() {
    customerService.createCustomer(new Customer(1L, "George"));
    customerService.createCustomer(new Customer(2L, "John"));

    List<Customer> customers = customerService.getAllCustomers();
    assertEquals(2, customers.size());
  }
}

Here's what the code does:

• PostgreSQLContainer is declared as a static field. The container starts before all tests and stops after all tests in this class.
• @BeforeAll starts the container, @AfterAll stops it.
• @BeforeEach initializes CustomerService with the container's JDBC parameters and deletes all rows to give each test a clean database.

Key observations:

• Because the container is a static field, it's shared across all test methods in the class. You can declare it as a non-static field and use @BeforeEach/@AfterEach to start a new container per test, but this isn't recommended as it's resource-intensive.
• Even without explicitly stopping the container in @AfterAll, Testcontainers uses the Ryuk container to clean up containers automatically when the JVM exits.

JUnit 5 extension annotations

The Testcontainers library provides a JUnit 5 extension that simplifies starting and stopping containers using annotations. To use it, add the org.testcontainers:testcontainers-junit-jupiter test dependency.

package com.testcontainers.demo;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.List;
import java.util.Optional;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.testcontainers.postgresql.PostgreSQLContainer;
import org.testcontainers.junit.jupiter.Container;
import org.testcontainers.junit.jupiter.Testcontainers;

@Testcontainers
class CustomerServiceWithJUnit5ExtensionTest {

  @Container
  static PostgreSQLContainer postgres = new PostgreSQLContainer(
    "postgres:16-alpine"
  );

  CustomerService customerService;

  @BeforeEach
  void setUp() {
    customerService =
    new CustomerService(
      postgres.getJdbcUrl(),
      postgres.getUsername(),
      postgres.getPassword()
    );
    customerService.deleteAllCustomers();
  }

  @Test
  void shouldCreateCustomer() {
    customerService.createCustomer(new Customer(1L, "George"));

    Optional<Customer> customer = customerService.getCustomer(1L);
    assertTrue(customer.isPresent());
    assertEquals(1L, customer.get().id());
    assertEquals("George", customer.get().name());
  }

  @Test
  void shouldGetCustomers() {
    customerService.createCustomer(new Customer(1L, "George"));
    customerService.createCustomer(new Customer(2L, "John"));

    List<Customer> customers = customerService.getAllCustomers();
    assertEquals(2, customers.size());
  }
}

Instead of manually starting and stopping the container in @BeforeAll and @AfterAll, the @Testcontainers annotation on the class and the @Container annotation on the field handle it automatically:

• The extension finds all @Container-annotated fields.
• Static fields start once before all tests and stop after all tests.
• Instance fields start before each test and stop after each test (not recommended — it's resource-intensive).

Singleton containers pattern

As the number of test classes grows, starting containers for each class adds up. The singleton containers pattern starts all required containers once in a common base class and reuses them across all integration tests.

Define the base class

Create an abstract base class that starts the containers in a static initializer:

package com.testcontainers.demo;

import org.testcontainers.postgresql.PostgreSQLContainer;
import org.testcontainers.kafka.ConfluentKafkaContainer;

public abstract class AbstractIntegrationTest {

   static PostgreSQLContainer postgres = new PostgreSQLContainer(
           "postgres:16-alpine");
   static ConfluentKafkaContainer kafka = new ConfluentKafkaContainer(
           "confluentinc/cp-kafka:7.8.0");

   static {
       postgres.start();
       kafka.start();
   }
}

The containers start once when the class loads and Testcontainers uses the Ryuk container to remove them after the JVM exits.

[!TIP] Instead of starting containers sequentially, start them in parallel using Startables.deepStart(postgres, kafka).join();

Extend the base class

Each test class inherits from the base class and reuses the same containers:

class ProductControllerTest extends AbstractIntegrationTest {

   ProductRepository productRepository;

   @BeforeEach
   void setUp() {
       productRepository = new ProductRepository(...);
       productRepository.deleteAll();
   }

   @Test
   void shouldGetAllProducts() {
       // test logic using the shared postgres container
   }
}

Avoid a common misconfiguration

A common mistake is combining singleton containers with the @Testcontainers and @Container annotations:

// DON'T DO THIS — containers will stop after each test class
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@Testcontainers
public abstract class AbstractIntegrationTest {

   @Container
   static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>(
           DockerImageName.parse("postgres:16-alpine"));

   @DynamicPropertySource
   static void configureProperties(DynamicPropertyRegistry registry) {
       registry.add("spring.datasource.url", postgres::getJdbcUrl);
       registry.add("spring.datasource.username", postgres::getUsername);
       registry.add("spring.datasource.password", postgres::getPassword);
   }
}

The @Testcontainers extension stops containers at the end of each test class. Subsequent test classes reuse the cached Spring context, but the containers are already stopped — causing connection failures.

Instead, use a static initializer or @BeforeAll to start the containers, without the @Testcontainers and @Container annotations.

Summary

• Use JUnit 5 lifecycle callbacks (@BeforeAll/@AfterAll) for explicit control over container startup and shutdown.
• Use extension annotations (@Testcontainers/@Container) for less boilerplate in single test classes.
• Use the singleton containers pattern (static initializer in a base class) to share containers across multiple test classes.
• Don't mix singleton containers with @Testcontainers/@Container annotations.

Further reading

• Testcontainers JUnit 5 quickstart
• Testcontainers singleton containers pattern
• Testing a Spring Boot REST API with Testcontainers