Mastering Property Override: spring.datasource.url in Spring Boot Explained

When working with a Spring Boot application, you might need to override the spring.datasource.url property in the application.properties file to connect to a different database.

Ways to Override the Property

There are several ways to override the spring.datasource.url property:

1. Using Command Line Arguments: You can pass the property value as a command line argument when running the application. For example:

java -jar my-application.jar --spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase

2. Using System Environment Variables: Set the property value as an environment variable. For example, in a Unix-based system:

export SPRING_DATASOURCE_URL=jdbc:mysql://localhost:3306/mydatabase

3. Using an External Configuration File: You can provide an external properties file containing the override value. For example, create a file named application.yaml with the following content:

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mydatabase

Place this file in the application's classpath or provide its location through the --spring.config.name or --spring.config.location command line arguments.

Example

Let's consider an example where we want to override the spring.datasource.url property to connect to a PostgreSQL database:

1. Create a file named application.properties in your project's src/main/resources directory.

spring.datasource.url=jdbc:postgresql://localhost:5432/mydatabase

2. Start your Spring Boot application, and it will use the overridden property value.

By following one of the above methods, you can override the spring.datasource.url property in a Spring Boot application.properties file.