Maven Properties und Konfiguration

<?xml version="1.0" encoding="UTF-8"?>
        <project xmlns="http://maven.apache.org/POM/4.0.0"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
            <modelVersion>4.0.0</modelVersion>
            <parent>
                <groupId>at.aydin.academy</groupId>
                <artifactId>21mavenpropertiesconfig-pair</artifactId>
                <version>1.0.0</version>
                <relativePath>../pom.xml</relativePath>
            </parent>
            <artifactId>typed-config-modern</artifactId>
            <packaging>jar</packaging>
            <name>Typed Config Modern</name>

            <dependencies>

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <scope>test</scope>
</dependency>

            </dependencies>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                    </plugin>

                </plugins>
            </build>
        </project>

package at.aydin.lab.config.modern;

// Design Pattern: Configuration Object
// Zweck: Zusammengehörige Einstellungen werden typisiert und validiert gebündelt.
public record ApplicationConfig(int serverPort, boolean featureEnabled) {
    public ApplicationConfig {
        if (serverPort < 1 || serverPort > 65535) throw new IllegalArgumentException("serverPort");
    }
}

package at.aydin.lab.config.modern;

import java.util.*;

// Design Pattern: Factory
// Zweck: Zentralisiert Priorität, Parsing und Validierung verschiedener Konfigurationsquellen.
public final class ConfigFactory {
    public ApplicationConfig from(Properties p, Map<String, String> env) {
        int port = Integer.parseInt(env.getOrDefault("APP_PORT", p.getProperty("server.port", "8080")));
        boolean enabled = Boolean.parseBoolean(env.getOrDefault("FEATURE_ENABLED", p.getProperty("feature.enabled", "false")));
        return new ApplicationConfig(port, enabled);
    }
}

package at.aydin.lab.config.modern;

import org.junit.jupiter.api.Test;
import java.util.*;
import static org.junit.jupiter.api.Assertions.*;

class ConfigFactoryTest {
    @Test
    void environmentOverridesProperties() {
        Properties p = new Properties();
        p.setProperty("server.port", "8080");
        assertEquals(9090, new ConfigFactory().from(p, Map.of("APP_PORT", "9090")).serverPort());
    }
}