Test profiles and configuration in Spring Boot - Mini Project: Build & Apply

Test profiles and configuration

📖 Scenario: You are building a Spring Boot application that needs to behave differently in testing and production environments. You want to use Spring profiles to separate configuration for tests and for normal running.

🎯 Goal: Create a Spring Boot application with two profiles: test and default. Configure a property app.message differently for each profile. Write a simple test that uses the test profile and checks the message.

📋 What You'll Learn

Create an application property app.message with value Production Message in the default profile

Create a test profile property app.message with value Test Message

Write a Spring Boot test class that activates the test profile

Write a test method that asserts the app.message property value is Test Message

💡 Why This Matters

🌍 Real World

Many applications need different settings for testing, development, and production. Spring profiles help manage these differences cleanly.

💼 Career

Understanding Spring profiles and configuration is essential for backend developers working with Spring Boot to write maintainable and testable applications.

1

Create default application properties

Create a file named src/main/resources/application.properties and add the line app.message=Production Message to set the default message.

Spring Boot

# Create src/main/resources/application.properties with app.message=Production Message
# Your code here

Need a hint?

This file sets the default configuration for your Spring Boot app.

2

Create test profile properties

Create a file named src/test/resources/application-test.properties and add the line app.message=Test Message to set the message for the test profile.

Spring Boot

app.message=Production Message
# Create src/test/resources/application-test.properties with app.message=Test Message
# Your code here

Need a hint?

This file overrides properties when the test profile is active.

3

Write a Spring Boot test class with test profile

Create a test class named MessageServiceTest in package com.example.demo. Annotate it with @SpringBootTest and @ActiveProfiles("test"). Inject Environment and write a test method testAppMessage() that asserts environment.getProperty("app.message") equals Test Message.

Spring Boot

app.message=Production Message

# In src/test/resources/application-test.properties
app.message=Test Message

// Create MessageServiceTest.java with @SpringBootTest and @ActiveProfiles("test")
// Inject Environment and write testAppMessage() to assert app.message equals "Test Message"
// Your code here

Need a hint?

Use @ActiveProfiles("test") to activate the test profile during this test.

4

Add main application class

Create a main Spring Boot application class named DemoApplication in package com.example.demo with @SpringBootApplication annotation and a main method that runs SpringApplication.run(DemoApplication.class, args).

Spring Boot

app.message=Production Message

# In src/test/resources/application-test.properties
app.message=Test Message

package com.example.demo;

// Create DemoApplication.java with @SpringBootApplication and main method
// Your code here

Need a hint?

This is the entry point of your Spring Boot application.