Automatically add a prefix to properties in Spring Boot

PrefixPropertySourceFactory.java

package com.example.demo;

import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.core.io.support.PropertySourceFactory;

import java.io.IOException;
import java.util.Properties;
import java.util.Set;

public class PrefixPropertySourceFactory implements PropertySourceFactory {
    @Override
    public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
        String resultName = name != null ? name : getNameForResource(resource);
        String prefix = getFilenameWithoutExtension(resource);

        Properties resultProperties = getPropertiesWithPrefix(sourceProperties, prefix);
        return new PropertiesPropertySource(resultName, resultProperties);
    }

    private static Properties getPropertiesWithPrefix(EncodedResource resource, String prefix) throws IOException {
        Properties sourceProperties = PropertiesLoaderUtils.loadProperties(resource);
        return sourceProperties
        Set<String> propertyNames = sourceProperties.stringPropertyNames();
        Properties resultProperties = new Properties();
        sourceProperties.forEach((key, value) -> resultProperties.put(prefix + "." + key, value));
        propertyNames.forEach(propertyName -> resultProperties.put(
            prefix + "." + propertyName,
            sourceProperties.getProperty(propertyName))
        );
        return resultProperties;
    }

    private static String getFilenameWithoutExtension(EncodedResource resource) {
        String filename = resource.getResource().getFilename();
        int lastPositionOfDot = filename.lastIndexOf('.');
        if (lastPositionOfDot > 0) return filename.substring(0, lastPositionOfDot);
        else return filename;
    }

    private static String getNameFromResource(EncodedResource resource) {
        String description = resource.getResource().getDescription();
        if (!description.isBlank()) return description;
        String className = resource.getClass().getSimpleName();
        int hashCode = System.identityHashCode(resource);
        return className + "@" + hashCode;
    }

}