외부 설정 우선순위

package board.config;

import java.util.Map;

import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.StandardEnvironment;

public final class EnvironmentPriorityDemo {
    private EnvironmentPriorityDemo() {
    }

    public static void main(String[] args) {
        var environment = new StandardEnvironment();
        environment.getPropertySources().addLast(new MapPropertySource(
                "packaged-defaults",
                Map.of("board.api.base-url", "https://api.internal")));
        environment.getPropertySources().addFirst(new MapPropertySource(
                "deployment-override",
                Map.of("board.api.base-url", "https://api.production")));

        System.out.println(environment.getRequiredProperty(
                "board.api.base-url"));
        System.out.println(environment.getPropertySources().stream()
                .filter(source -> source.containsProperty("board.api.base-url"))
                .map(source -> source.getName())
                .toList());
    }
}

https://api.production
[deployment-override, packaged-defaults]

package board.config;

import java.net.URI;
import java.time.Duration;

import org.springframework.core.env.Environment;

public record BoardApiSettings(URI baseUrl, Duration timeout, int poolSize) {
    public BoardApiSettings {
        if (!baseUrl.getScheme().equals("https")) {
            throw new IllegalArgumentException("baseUrl must use https");
        }
        if (timeout.isNegative() || timeout.isZero()) {
            throw new IllegalArgumentException("timeout must be positive");
        }
        if (poolSize < 1 || poolSize > 64) {
            throw new IllegalArgumentException("poolSize must be between 1 and 64");
        }
    }

    public static BoardApiSettings from(Environment environment) {
        return new BoardApiSettings(
                URI.create(environment.getRequiredProperty("board.api.base-url")),
                Duration.parse(environment.getProperty(
                        "board.api.timeout", "PT2S")),
                environment.getProperty("board.api.pool-size", Integer.class, 8));
    }
}

package board.config;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class BannerConfiguration {
    @Bean
    Banner banner(
            @Value("${board.banner:회원 게시판}") String text,
            @Value("${board.banner-visible:true}") boolean visible
    ) {
        return new Banner(text, visible);
    }

    public record Banner(String text, boolean visible) {
        public String render() {
            return visible ? text : "";
        }
    }
}

missing key: board.api.base-url -> REQUIRED_PROPERTY_MISSING
raw value: board.api.pool-size=fast -> TYPE_CONVERSION_FAILED
resolved value: board.api.pool-size=128 -> DOMAIN_RANGE_REJECTED
winning source: commandLineArgs -> STALE_OVERRIDE_WON