Spring Boot application.properties vs. application.yml

By Atul Rai | Last Updated: June 10, 2023 Previous       Next

application.properties and application.yml both are the configuration files used in Spring Boot to configure application-specific properties. The main difference between them lies in their syntax and structure.

1. application.properties

1. It uses a simple key-value pair format.
2. Properties are defined using the key=value syntax.
3. Properties can be written in a single line or multiple lines, but each property is represented by a single key-value pair.

server.port=8080

# MySQL database connection strings
spring.datasource.url=jdbc:mysql://localhost:3306/demo
spring.datasource.username=root
spring.datasource.password=root

# JPA property settings
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.show_sql=true

1.1 Advantages of application.properties

1. Simplicity: The properties file format is straightforward and easy to understand. It uses a simple key-value pair syntax, making it accessible to developers familiar with traditional Java properties files.
2. Familiarity: Properties files have been widely used in Java applications for a long time. Many developers are already familiar with the format, making it easier to understand and maintain.

2. application.yml

1. It uses a YAML (YAML Ain’t Markup Language) format.
2. Properties are defined using indentation and hierarchical structure.
3. Properties can be written in a more structured manner using indentation and nesting.
4. YAML supports lists and maps, making it easier to represent complex configurations.

server:
    port: 8080
	
spring:
    datasource:
        password: root
        url: jdbc:mysql://localhost:3306/demo
        username: root
    jpa:
        hibernate:
            ddl-auto: update
        properties:
            hibernate:
                show_sql: true

2.1 Advantages of application.yml

1. Readability: YAML offers a more human-friendly and readable syntax. Its use of indentation and hierarchical structure allows for a more organized and visually appealing representation of configurations, especially for complex settings.
2. Conciseness: YAML can be more concise than properties files, as it uses indentation to denote structure and eliminates the need for explicit key-value separators and quotation marks. This can lead to shorter and more compact configuration files.
3. Enhanced Features: YAML supports features such as lists and maps, making it easier to represent complex configurations and relationships between properties. This can be beneficial when working with more intricate setups.

Summary

The choice between application.properties and application.yml depends on personal preference and the specific needs of your project. Both formats are supported by Spring Boot, and you can choose the one that you find more readable or convenient for your configuration needs. YAML often provides a more human-friendly and organized way to represent complex configurations, while properties files are simpler and widely used in traditional Java applications.

References

1. Externalized Configuration- Spring Boot Doc