Spring Boot: ConfigFileApplicationListener Deprecated - Use EnvironmentPostProcessor

The class 'ConfigFileApplicationListener' in the 'org.springframework.boot.context.config' package is deprecated and can only be used as an 'EnvironmentPostProcessor'. This means that instead of using 'ConfigFileApplicationListener' directly, you should implement your own 'EnvironmentPostProcessor' and use that to perform any necessary configuration file processing.

To implement your own 'EnvironmentPostProcessor', you need to create a class that implements the 'EnvironmentPostProcessor' interface and override the 'postProcessEnvironment()' method. In this method, you can perform any necessary configuration file processing based on the provided 'Environment' object.

Here's an example of how you can implement your own 'EnvironmentPostProcessor':

import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.core.env.ConfigurableEnvironment;

public class MyEnvironmentPostProcessor implements EnvironmentPostProcessor {

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        // Perform your configuration file processing here
    }
}

To use your 'EnvironmentPostProcessor', you need to register it in your Spring Boot application by adding a 'META-INF/spring.factories' file in your resources directory. In this file, you can specify your 'EnvironmentPostProcessor' implementation as follows:

org.springframework.boot.env.EnvironmentPostProcessor=com.example.MyEnvironmentPostProcessor

Make sure to replace 'com.example.MyEnvironmentPostProcessor' with the fully qualified name of your 'EnvironmentPostProcessor' implementation.

By implementing your own 'EnvironmentPostProcessor', you can perform any necessary configuration file processing without relying on the deprecated 'ConfigFileApplicationListener'.