Configuring the Application using Application Properties or YAML Files

In Spring Boot, configuring your application is a crucial step in ensuring it can function as intended. One way to configure your Spring Boot application is by using application properties or YAML files. This article will explore in detail how to leverage these configuration options effectively.

Application Properties vs YAML Files

Before diving into its usage, it's important to understand the difference between and YAML files. While both serve the purpose of application configuration, they have slight differences:

Application Properties:

  • Written in a key-value pair format.
  • Relies on .properties file extension.
  • Can be written in a plain text format.
  • Easy to use for small to medium-sized projects.

YAML Files:

  • Relies on .yml or .yaml file extension.
  • Written in a structured format using indentation.
  • Supports complex data structures like lists and maps.
  • Ideal for larger projects with more complex configurations.


Regardless of the chosen configuration format, Spring Boot will automatically pick up the configuration file during the bootstrap process. By default, it will search for or application.yml at the root of the classpath.

To configure the application, follow these simple steps:

  1. Create the configuration file: Create either or application.yml file in the appropriate location.

  2. Define the properties: Specify the necessary properties in the chosen configuration format. For example, to set the server port to 8080, you can use the following in


Or, in application.yml:

  port: 8080
  1. Access the properties in the application: In your Spring Boot application, you can now make use of these properties by using @Value annotation or the @ConfigurationProperties annotation.

For example, with @Value annotation:

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

public class MyComponent {

    private int serverPort;

    // Use the serverPort property as needed

Or, with @ConfigurationProperties annotation:

import org.springframework.stereotype.Component;

@ConfigurationProperties(prefix = "server")
public class MyComponent {

    private int port;

    // Generate the getter and setter for port property

    // Use the port property as needed

With these configuration options, you can easily customize various aspects of your Spring Boot application, from database connection settings to logging levels and more.


Configuring your Spring Boot application using application properties or YAML files allows you to easily fine-tune your application's behavior without modifying the source code. Whether you choose the simplicity of application properties or the versatility of YAML files, both options provide a flexible way to configure your application based on different environments, making your application development process more convenient and efficient.

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