参考：

https://www.zhangshengrong.com/p/2EaE59vBaM/

依赖 spring 的方式：

import jakarta.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

import java.lang.reflect.Field;
import java.nio.charset.StandardCharsets;
import java.util.Objects;

/**
 * @Author FengHao
 * @Date 2023/3/29
 * @Description: 项目启动时获取配置信息，根据需要添加
 **/
@Component
public class ConfigConstant {
    @Autowired
    private Environment env;

    public static String spring_application_name;
    public static String server_port;

    @PostConstruct
    public void readConfig() throws Exception {
        Field[] fields = ConfigConstant.class.getFields();
        for (Field field : fields) {
            field.set(null, getProperty(field.getName().replace("_", ".")));
        }
    }

    private String getProperty(String key) {
        return new String(Objects.requireNonNull(env.getProperty(key)).getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8);
    }
}

静态代码块的方式：

import java.io.InputStreamReader;
import java.lang.reflect.Field;
import java.nio.charset.StandardCharsets;
import java.util.Objects;
import java.util.Properties;

/**
 * @Author FengHao
 * @Date 2023/3/29
 * @Description: 不依赖spring, 单测调代码时使用
 **/
public class ConfigConstantNoSpring {
    public static String spring_application_name;
    public static String server_port;

    static {
        try {
            Properties props = new Properties();
            props.load(new InputStreamReader(
                    Objects.requireNonNull(ConfigConstantNoSpring.class
                            .getClassLoader().getResourceAsStream("application.properties")),
                    StandardCharsets.UTF_8));
            String profile = props.getProperty("spring.profiles.active");
            String envFile = "application-" + profile + ".properties";
            Properties envProps = new Properties();
            envProps.load(new InputStreamReader(
                    Objects.requireNonNull(ConfigConstantNoSpring.class
                            .getClassLoader().getResourceAsStream(envFile)), StandardCharsets.UTF_8));
            Field[] fields = ConfigConstant.class.getFields();
            for (Field field : fields) {
                field.set(null, envProps.getProperty(field.getName().replace("_", ".")));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}