public class Constants {



    public static String getUploadDir() {
        // 获取 JAR 包所在目录
        ApplicationHome home = new ApplicationHome(Constants.class);
        File jarDir = home.getDir();

        // 构建上传文件存储路径（JAR 同级目录下的 uploads 文件夹）
        File uploadDir = new File(jarDir, "uploads");
        if (!uploadDir.exists()) {
            uploadDir.mkdirs();
        }
        return uploadDir.getAbsolutePath();
    }

    public final static   String UploadDir = getUploadDir();
    }

public static String getUploadDir() 方法为获取路径 在java - jar 启动方式目录如下

打印即可看到绝对路径