Java environment config loader with defaults

import java.util.Map;

public final class EnvConfig {
    public record Config(String host, int port, boolean debug) {}

    public static Config load(Map<String, String> env) {
        String host = env.getOrDefault("APP_HOST", "localhost");
        if (host.isBlank()) throw new IllegalStateException("APP_HOST must not be blank");
        int port;
        try {
            port = Integer.parseInt(env.getOrDefault("APP_PORT", "8080"));
        } catch (NumberFormatException e) {
            throw new IllegalStateException("APP_PORT must be an integer", e);
        }
        if (port < 1 || port > 65535) throw new IllegalStateException("APP_PORT out of range: " + port);
        return new Config(host, port, Boolean.parseBoolean(env.getOrDefault("APP_DEBUG", "false")));
    }
}